Forensic Chemistry DFS MANNUAL.doc

8/14/2019 Forensic Chemistry DFS MANNUAL.doc

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INTRODUCTION

The identification and estimation of different types of crime exhibits such asdrugs, cement, petroleum product and their residues, liquor, egetable oiland fats, dyes, gold, chemicals etc in forensic science laboratories required

high degree of s!ill and expertise" The forensic scientists are follo#ingarious methods for the chemical analysis of these substances in thelaboratories" The $or!ing %rocedure &anual of Chemistry had been made atC'(), *yderabad #ith the consultation of a team of arious 'orensic(cientists of the country in the year +"

SECTION - 1

CEMENT, MORTAR AND CONCRETE

1.1. Title- Cement, mortar and concrete

1.2. Scope: Detection and estimation of the constituents of cement, mortarand concrete in crime cases"

1.3. Purpose:To !no# the precise chemical composition of cement, mortarand concrete and to assist inestigating agencies and la# enforcementbodies"

1.4 Resposi!ilit": Reporting officers and supporting scientific staff"

1.#. Itro$uctio:

'orensic (cience )aboratories receie cement cases under different crimeheads li!e .ssential Commodities /ct", Indian %enal Code 0I%C1 andoccasionally under Cement Orders /ct" Cement is one of the mostimportant materials in building construction" In chemical examination,testing of cement is done to chec! its purity and characteri2ation" *enceonly a fe# parameters li!e soluble calcium oxide, silica etc" are determinedas per Indian (tandards specifications" Concrete and &ortar are referred to'orensic (cience )aboratories in cases of building collapse"

1.% Ce&et

%ortland cement may be defined 31'as a product obtained by intimatelymixing together calcareous and argillaceous, or other silica, alumina, andiron oxide4bearing materials, burning them at a clin!ering temperature andgrinding the resulting clin!er" In +567 8oseph /spdin gae the name portland


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cement because this product resembled the colour of the stones from%ortland, .ngland" Cements are mainly mono silicates of calcium, soluble indilute acids and al!ali"

1.%.1. COMPOSITION O( PORT)AND CEMENT:

)ime CaO 9:49;4:5 ++ ++

1.%.3.1.Ce&et:

1.%.3.1*..$hen the sample is dra#n from a cement bag, the details printedon the bag and another mar!ing thereon should be carefully noted andincorporated in the for#arding letter" + !g sample of cement should be sentin an airtight plastic ?ar if aailable or it should be securely pac!ed inpolythene bag and then in bro#n paper to aoid exposure to moisture"(ampling is done as per the procedure as laid do#n in the Indian (tandard%rocedures of random sampling"

1.%.3.1!.S*&pli o0 S&*ll u*tities0)ess than +6 bags or pac!ages1-$hen number of bags or other pac!ages containing the cement bears thesame label on all the pac!ages and are appearing to be similar, in such casesabout +!g sample of cement 0in an air tight plastic ?ar1 shall be dra#n fromeach bag and sent for analysis"

1.%.3.1c.S*&pli o0 l*re u*tities 0&ore than +6 bags or pac!ages1-$hen number of bags containing the cement bear the same labels on thepac!ages and are appearing to be similar, in such cases the grouping mustbe done" .ach group should contain about equal no" of bags and 6: percent

of sample #eighing + !g 0in an air tight plastic ?ar1 from each group shall bedra#n into air tight plastic ?ar and sent for analysis"

1.%.3.2.MORTAR:

+46 Bg of mortar sample accompanied by + !g each of cement and or limeand sand if aailable from the field shall be sent for analysis" .ery articleshould be independently pac!ed"

1.%.3.3.CONCRETE:

Concrete lumps, about >4=!g accompanied by + !g each of cement, sand andaggregate if aailable from the field shall be sent for analysis" .ery articleshould be independently pac!ed"

1.%.4. METODS O( ANA)?SIS E@PERIMENTA) re0.3':

1.%.4.1.Ce&et:


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1.%.4.1.1.T"&olpt*leiTest:

0Thymolphthalein Indicator :"+< in ethyl alcohol1

Ta!e +::4+=: mg of cement sample in a test tube, add +46 ml #ater and 6

drops of indicator, deelopment of blue colour indicates the presence ofcement, No colour indicates that the sample is stone po#der"

1.%.4.1.2.e*ti test:

Ta!e :"= gm of sample, heat it for about 6: min" on a steel plate"

a1" Change in colouradulterated cement"

b1" No change in colour

unadulterated cement"

1.%.4.1.3.Per0or&*ce Test-

&a!e thic! slurry of cement #ith about + part of cement #ith one part of#ater and put in an empty matchbox" The cement gets hardened" Theperformance is tested after 67 hrs" ?ust by remoing matchbox and chec!ingapprox" strength of the cement by fingers, if the bloc! brea!s easily, thesetting property is said to be poor" If the bloc! does not brea! by fingers" Theperformance is said to be good"

1.%.4.1.4.Aci$ isolu!le-

Ta!e :"= 4+": gm cement in a +:: ml bea!er add 6: ml #ater to ma!e apaste follo#ed by = ml conc" hydrochloric acid, add 6: ml #ater, stir, digeston #ater bath for fie minutes, no lumps should be formed" Digest further foranother +: minutes, filter through ashless filter paper till chloride free"Residue dried in oen and further incinerated in furnace at 5::C4::C for+ hr" #eigh the residue, till constant #eight" Calculate percent acid insoluble"

1.%.4.1.#.Silic*-

Concentrate filtrate from 6"9"7"+"7 on hot plate to dryness, further drycompletely #ithout charring, then add 6: ml +-+ *ydrochloric acid and digeston #ater bath for +: minutes stir #ell, and filter on ashless filter paper tillchloride free" Dry the residue 0%recipitated silica1 in oen for +hr and thenincinerate in furnace at 5::C4::C for +hr"#eigh the residue, till constant#eight" $eight of silica obtained is noted" 06:< (ilica E +::< cement1"

1.%.4.1.%.Co&!ie$ (erric Oi$e *$ Alu&i*:

Concentrate the filtrate from 6"9"7"+"= to about 6::4ml by boiling then add 64> drops of nitric acid to oxidise any ferrous iron to ferric condition" /dd +46


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grams of ammonium chloride, stir, and then treat the filtrate #ith conc"ammonia solution till smell of ammonia persists then boil the solutioncontaining the ppts" of 'e and /l hydroxides for fe# minute" 'ilter and #ashthe ppt" #ith hot #ater" Dry the ppt" in oen and ignite in platinum crucibletill constant #eight at +:=:C to ++::C" $eigh as alumina and ferric oxide"

1.%.4.1.8.Deter&i*tio o0 BC*lciu&B!" EDTA Titr*tio- 4

0@y %atton ReederFs indicator1

Ta!e filtrate from ferric oxide and alumina determination in 6=: ml Aol" flas!ad?ust Aol" to 6=: ml" Ta!e out 6=ml soln" in titration flas! add =: ml #ater,=ml 0+-+1 glycerol #ith constant stirring then add =ml diethylamine, furtheradd =49 pellets of NaO* 0p* should be more than +61 sha!e #ell, further add=:mg of %atton ReederFs indicator, sha!e #ell and titrate against :":+&.DT/ soln" colour change iolet to blue"

+ml :":+ & .DT/ E :"=9:5 mg of CaO"

09: < CaO E +::< Cement1 and CaO< E > (ilica : minutes, add =: ml #ater and titrate against :"= N NaO* usingphenolphthalein as an indicator" /lso perform a blan! titration" Colour

change is colourless to pin!"

Cement < E 65 H N H Diff" in Reading 0NE Normality of NaO*1

1.8. Mort*r:

&ortar is the blend of cement and sand in arious proportions used forarious purposes" The mortar used for bric!#or! in house #alls is generally+-7 in proportions" 'or testing of mortar and bric! good piece of mortaradhering to bric! from debris should be collected"

1.8.1 Testi o0 Mort*r:

*eat good piece of mortar approx" 6:: gms is heated in oen at ++:C for +=min" cool and then #eigh" (eparate the cement portion from sand by slo#lygrinding the lump in iron mortar" 0to separate sand from cement lumps"1(iee the material and ma!e three fractions" %o#der, fine sand and coarsesand" $eigh indiidually and record" Ta!e about =4+: gm of each fraction inbea!er, add =4+: ml >"> N *Cl till all the material is #et #ith *Cl, if required,


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add further =4+: ml *Cl, to dissole the material" The cement portion getsdissoled and sand portion gets separated from cement, digest on #aterbath for +: minutes filter the liquid through filter paper, #ash #ith #atertill chloride free" The filtrate is eaporated and silica determined as in earlierpart, from silica cement portion in each fraction is determined, from total

#eight, #eight of sand obtained by subtracting #t" Of cement and hence theratio of cement to sand is calculated" /lso < of cement in the sample iscalculated"

1.8.2 EDTA Titr*tios: 'or filtrate same as cement normally the ratio ofcement- sand used in plastering #or! is +-7 0The ratio used for compound#alls and such other #or! is +-9 to +-51"

1.;. Cocrete:

1.;.1. Cocrete is a blend of cement, sand and aggregate in different

proportions used for different purposes" Normally samples from debrisselected are pieces of beams and slabs ta!en for analysis" /bout +6!gsample is required for analysis dry the piece from slabbeam in oen at++:C for += minutes", cool, and #eigh" Then grind the sample so thatcement particle gets separated from sand and aggregate" (iee the bul!#ith different mesh si2e siees, to separate po#der, fine sand, coarse sandand aggregate" $eigh the fractions so separated indiidually" Ta!e about =49gm from po#der fraction and fine sand fraction, about =:49: gm fromcoarse sand and about +::4+=: gms of aggregate fraction for actual silicaand calcium oxide determination" Ta!e all the four fractions as aboe in 6=:ml bea!ers, add sufficient quantity of >"> N *Cl to dissole the adhering

cement particles" Then digest on #ater bath for +:4+= minutes and filter" Thefiltrate so obtained is used for silica determination"

1.;.2. Silic*

'iltrate eaporate the filtrate to dryness on hot plate, dry silica remains inthe bea!er along#ith calcium and aluminium salts" Then add >"> N *Cl anddigest on #ater bath for = mins" 'ilter the silica through ashless filter paper,#ash #ith #ater until chloride free" Dry the silica in oen and further infurnace at 5::C4+:::C for 6 hrs, $ash the silica so obtained" 'rom silicacalculate the #eight of cement obtained in different fractions 06:< silica E

+::< cement1" .ach fraction contains some cement portion and rest beingfine sand, sand and aggregate respectiely" Ta!e sand and fine sandfractions together" Thus calculate the total cement, total sand and totalaggregates present in the sample, and hence calculate the ratio of cement-sand- aggregate also calculate the cement percentage" 'rom filtrate of silica,calculate CaO < as detailed in cement, from CaO< also calculate the : mlminute


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Oen Temperature- %rogrammed from 9:oC to 6=:oC at 7oC per min"

Detector Temperature- 6;=oC

In?ector Temp- 6=:oC

2.%.3 C*pill*r" >*s Cro&*tor*p" 3

Oper*ti Co$itios

Column- =: M +::m Glass Capillary x :":+:P ID

%ac!ing- OA +:+, or its equialent column

Detector- 'lame Ioni2ation Detector 0'ID1

Carrier Gas- Nitrogen

'lo# Rate- + mlminute

Oen Temperature- %rogrammed from 9:oC to 6=:oC at 6oC per min"

Detector Temperature- 6;=oC

In?ector Temp- 6=:oC

Re0ereces:

+" @aggi TR, &urthy *RB, %rasad Aeena /, Detection and characteri2ation ofpetroleum residues by Thin )ayer Chromatography, 8" Indian /cad" 'orens"(ci",+5;, ol"69 No"6, pp >94>5

6" /rora BB, Golani *C, Narayans#ami B, Detection of adulteration inpetroleum products by gas liquid chromatography, 8" Indian /cad" 'orens"(ci" +;=+7- pp 74+>"

>" / unified scheme for the analysis of light petroleum products used as fireaccelerants by Daid $illson, 'orensic (cience, +;;, ol"+:, pp 67>46=6"

+" /B, @hat @(, %andya A(, Detection of !erosene residue on T)C, 8" Indian/cad" 'orens" (ci",+;;, ol"+9 No"+, pp =74=9"

6" Chhabra B(, Ra?anshi /C, Narain (ri, Thin )ayer Chromatography methodfor identification of petrol as fire accelerants, Indian 8ournal of 'orensic(ciences, ++, ol"=, pp+;>4+;="

>" Narayans#ami B, @ami *), Gas4chromatography in detection of !eroseneresidues, International Criminal %olice Reie#, +;+, No"6=+, pp 6+9466+"

7" &attoo @N, %ai %%, $ani /B, (pectroscopic detection of !erosene residuesin forensic #or!, 8" Indian /cad" 'orens" (ci",+;:, ol", No"+, pp 745"


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=" /rora @@, Transmission .lectron &icroscopic (tudies of &orphologyand Crystallography of %articulate .missions in (mo!es, 'orensic(cience International, >6, +59, pp +5=4+6


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SECTION - 3

OI)( '/T(

1.1 Title- Oils and 'ats"

3.2 Scope- /nalysis and characteri2ation of arious oils and fats"

3.3 Purpose- To determine the quality and adulteration of oils and fats"

3.4. Resposi!ilit"- Reporting officer and supporting scientific staff"

3.#. Itro$uctio

Oils and fats analysis coers a ma?or area in forensic chemistry as these areoften adulterated in arious #ays i2 adulteration of lo#er grade, differentorigin 0egetable oil by animal fat or ice4ersa1 or misbranding orcontrabanding of products etc" the cases as aboe may occur frequently asoils and fats are extremely used as coo!ing media and also in industries li!epaints, arnishes, pharmaceutical industries" There may be theft cases orillegal possession related to oils and fats" In the aboe case the samples arefrequently sent for their examinations for different purposes under .ssentialCommodities /ct 0."C /ct1"

Oils and fats may be diided into t#o classes based on their origin, egetable

oil and animal fat" The #ords oil and fat are synonymous" They differ in theirphysical state i"e oil is liquid and fat is solid" The egetable oils includegroundnut, sunflo#er, linseed, coconut, mustard, palm, sesame, cottonseed,rapeseed, soyabean, castor, pea4nut, rice bran oils etc" there may behardened fat from egetable oil by the hydrogenation of oils 0product4Aanaspati1" The animal fat is aailable in the form of butter, ghee, tallo#and lard" (ome times tallo# or lard is added to egetabledesi4ghee oranaspati"

In case of analysis of samples for#arded to forensic laboratories under."C"/ct, the samples are ery often required to be examined for arious

parameters based on physical and chemical properties of indiidual oil andfat to ascertain the nature, quality, adulteration etc" (ometimes chemicaltests are performed to identify a specific oil, adulteration, or rancidity0fouling of oils1"

The examination of oils and fats is based on their composition" Oils and fatsare tri4glycerides of fatty acids of saturated and unsaturated acids 0oleic,linoleic, linolenic1 in arying proportions" These may contain fatty acids of


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definite carbon number in higher proportion in some oils i2 arachidic acid inarachis oil, groundnut, nut and peanut oil, crucic acid 0in mustard, rapeseedand rape oil1, normal and iso propionic and butyric acid in butter and ghee0both animal fat1 or ary in the percentage of free acids 0 due to hydrolyticsplitting of glycerides of en2ymes1 or ary in the nature and percentage of

sterols in the unsaponifiable matter in animal fats and egetable oils0cholesterol in animal fat and phytosterols in egetable oils1 or ary in dryingproperties 0 the tendency to form solid film due to unsaturation"1 or ary intheir tendency to undergo addition #ith iodine or iodine monochloride 0dueto ariation in unsaturation present1" The aboe ariation in fatty acid profileand other not fatty acid or non glyceride constituent 0unsaponifiable matteri"e" sterols- higher alcohols1 are responsible to impart effect on their physicaland their chemical properties i2" colour, refractie index, melting point,saponification point, al!aline hydrolysis behaiour, additie reactions etc" thedifferences in physical behaiour and parameters based on chemicalcharacteristics 0saponification alue, acid alue, acetyl alue, Reichert4

&eissel alue, polens!e alue etc"1 proide analytical guideline or clues tothe classification or characteri2ation of different oils and fats" Chemical testsare often performed to detect adulteration or rancidity" *o#eer, qualityassurance or adulteration chec!ing become ery often difficult #hen alueson some parameters oerlap" Then the help of other physical characteristicsor special parameter i2" Reichert4&eissel alue, polens!y alue in case ofadulteration of ghee or anaspati by hard and tallo# or by instrumentaltechnique specially GC for fatty acid profiling" Aarious options are to beapplied profitably to get the analysis done in a short time" The interpretationof the alues on parameters requires special !no#ledge and expertise"

3.%. Meto$s- 3.%.1.SAMP)IN>:

Te s*&pli o0 te ei!its to !e collecte$ 0or **l"sis &*" !e$oe *s per te proce$ure l*i$ $o7 i te I$i* St*$*r$Proce$ures o0 S*&pli o0 Oils + (*ts.

>"; /N/)L(I(-

>";"+" (ample %reparation-

>";"+"+" )iquid oils-

'ilter the oil sample through $hatmann filter paper no"+"

>";"+"6" (olid and (emi solid oils-

&elt the solid or semi solid samples of oils and fats heated in an oen to +::Caboe the melting point of the fat" 'ilter the melted sample through$hatmann filter paper no"+"


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3.8.2. CEMICA) TESTS:

3.8.2.1 >RO=ND N=T OI): 1

Ta!e one ml of the sample of oil in a conical flas!, add = ml of +"= N alcoholic

potash and saponify completely on a boiling #ater bath using an aircondenser to aoid loss of alcohol" It ta!es about +: minute" During thesaponification s#irl the flas! many times, cool, add :"+ ml of phenolphthaleinindicator" Neutrali2e the solution exactly by adding dil" /cetic acid 0Oneolume of glacial acetic acid Q t#o olumes of distilled #ater1 follo#ed byan extra amount of :"7 ml of acetic acid" &ix =: ml of ;:< alcohol fit athermometer into the flas! #ith the help of a cor! in such a #ay that thebulb of thermometer is dipped in the liquid but does not touch the bottom ofthe flas!" *eat the flas! on a #ater bath until the temperature reaches =::Cto become solution clear" Beep the flas! for cooling in air #ith frequentsha!ing until the temperature of the solution comes to 7::C" /ppearance of

turbidity in bet#een > to 7::

C indicates the presence pure groundnut oil"Cool the flas! #ith constant sha!ing in a cooling bath at += :Q +:C in such a#ay that the temperature falls roughly at the rate of 6:C per minute" Notethe turbidity temperature, #hich is the temperature at #hich the first distinctturbidity appears" This turbidity temperature is once again confirmed by alittle further cooling #hich results in the deposition of precipitate" Dissolethe precipitate by heating the contents at =::C on a #ater bath" /gain coolas aboe and ma!e an experiment for duplicate determination of turbiditytemperature" Duplicate shall agree #ith in Q :"=:C"

Re*ets-

1. Alcoolic Pot*s G1.# NF:

Dissole 5"= g of potassium hydroxide in +:: ml purified rectified spirit" Thesolution may be !ept in dar! colour bottle preferably"

6" %urified Rectified (pirit-

Reflux +"6 litre of rectified spirit for half an hour in a distillation flas!containing +:g of caustic potash and 9 g of granulated aluminium oraluminium foil pieces" Distil and collect one litre after discarding the first

=:mm, this is purified, rectified spirit used for reagents"

3. Peolpt*lei I$ic*tor:

Ta!e :"= g of phenolphthalein and dissole in =:ml of purified rectified spiritand mix the solution #ith =:ml of distilled #ater"

3.8.2.2. SESAME OI): 1


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Ta!e = ml of the oil sample or melted fat in a cylinder or test tube #ith aglass stopper add = ml of hydrochloric acid and :"=ml of furfural solution 06AMIA >)A


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about :"= ml of chloroform and used it to carry out the T)C #ith follo#ingconditions"

St*tio*r" p*se: -(ilica gel G, :"6=mm thic!ness"

DeHelopi solHet:

%etroleum ether 07:49::C1 , diethyl ether and acetic acid0 9-7-+1"

DeHelop&et: 6: minutes

isu*li9*tio: Dry the plate at room temp" and #atch under U"A" )ight

O!serH*tio: -

+" /ppearance of > bluish green spots at about Rf alues:">7,

:"66, and :"+; on the plate indicates the positie test for thepresence of Baran?a oil" The detection limit is up to :":+


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DeHelop&et: /bout 7 minutes, 9 cm

isu*li9*tio: Dry the plate in air at room temperature, spray #ithfluorescin solution 0 6< soln" Of 6,;4dichloro4fluoresein in 9 < ethanol and#atch under U"A" )ight

O!serH*tio: - /ppearance of yello# fluorescent spots on the solent frontindicates the positie test for the presence of mineral oil" The egetable oilgies a yello# strea! about 64> cm long from the base"

3.8.2.11. DETECTION O( RANCIDIT? IN EDI


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>rou$ut oil:>::;, 6=7, 669, 65=7, +;7;, +79=, +7+5, +>;5, +6>;,++9>, +++,+:, 99, ;66

Cocout oil:6==, 667, 65=7, +;7;, +799, +7+5, +>;5, +665, ++9+, 96,;66"

3.8.4. DETECTION O( ACID AND CO)ORS IN EDI";"7"6" D.T.CTION O' CO/) T/R OI) (O)U@). CO)OR( IN .DI@). OI)(-

Ta!e about = ml of suspected sample of oil in test tubes, add about += ml ofpetroleum ether to each tube follo#ed by =ml of *Cl of differentconcentrations 07-+, >-+, 6-+, and +-+ *cl and #ater1 to different tubes"

Change in color indicate the presence of coal tar oil soluble colors in thesample"

3.8.4.3. ISO)ATATION AND DETECTION O( OI) SO)=47 times #ith 6= ml ofhexane and draining out the solent each time to remoe almost all the oil

leaing behind the silica gel in the flas!" .lute the coloring matter absorbedby the silica gel in the flas! by sha!ing #ith 6: ml of diethyl ether 64> times"Collect the diethyl ether extract in a bea!er" .aporate the solent on a hot#ater bath to concentrate, #hich can used to carry out the T)C #ithfollo#ing conditions"

St*tio*r" p*se: -(ilica gel G, :"6=mm thic!ness"


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DeHelopi solHet: @en2ene, hexane and acetic acid 09-7-+1"

DeHelop&et: +64+= cm

isu*li9*tio: Dry the plate at room temp" and heat the plate at +:::oc in

an oen for + hour"

O!serH*tios: - Natural colors li!e carotenes fades a#ay leaing oil solublecoal tar colors"

>";"=" D.T.R&IN/TION O' %*L(IC/) %RO%.RTI.( O' OI)(-

3.8.#.1. Deter&i*tio o0 &oisture *$ Hol*tile su!st*ces:

Carry out the determination of moisture and olatiles in duplicate"

Meto$-1$eigh =4+: gms of suspected sample of oil or fat in a tared metaldish of about ;cm dia and >47 cm deep #ith lid" &ixed the sample thoroughlybi stirring" )oose the lid and heat in an oen at +:>Q 6oC for > hours" Ta!eout the dish from the oen and close its lid" Cool it in desicator haingphosphorous pentoxide and #eigh" *eat once again for + hour and #eigh"Repeat the process to get concurrent readings #ith a difference of 6 mg

/*e o0 &oisture J $eight )oss$eight of oil ta!en K +::

Meto$-2 $eigh about +: gms but accurately of suspected sample of oil orfat in a tared glass bea!er #ith glass rod, cool it in a desiccator haing

phosphorous pentoxide and #eigh" *eat the bea!er #ith sample on anelectric hot plate #ith continuous stirring by glass rod" The complete remoalof moisture is indicated by the cessation of the rising bubbles and byabsence of foam, #hich can also be tested by !eeping a clean and dry #atchglass on the top of the bea!er and obsere the #ater apours, if any" Coolthe bea!er to room temperature in the desiccator and #eigh"

/ *e !" 6t. o0 &oisture *$ Hol*tiles cotet E $t" )oss$t"ofsample ta!en K +::

3.8.#.2 Deter&i*tio o0 Speci0ic >r*Hit"- 4 Determine the specific

graity of the oil by specific graity density bottle or a py!nometer methodat ambient temperature by noting do#n the #eight of specific graity bottle#ith oil, #ith #ater and the empty bottle"

$eight of bottle #ith oil 4 $eight empty bottle

Speci0ic >r*Hit" E 44444444444444444444444444444444444444444444444444444444


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$eight bottle #ith #ater M $t of empty bottle

3.8.%. CEMICA) CARACTERISTCS

3.8.%.1 Aci$ *lue:It is the number of milligrams of potassium hydroxide

required to neutralise the free fatty acid present in one gm of the oil or fat"The acid alue is determined by directly titrating the material in an alcoholicmedium #ith aqueous sodium or potassium hydroxide solution"

Re*ets-

*F Et"l *lcool 0=


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Re*ets: -

*F Alcoolic pot*ssiu& "$roi$e solutio:-Dissole >= to 7: gm ofpotassium hydroxide in 6: ml of distilled #ater, and add sufficient aldehydefree rectified spirit to ma!e up +::: ml" /llo# to stand oernight, decant the

clear liquid and !eep in a bottle closed tight #ith cor! or rubber stopper"

!F Peolpt*lei I$ic*tor solutio: - Dissole +": gm ofphenolphthalein in +:: ml of rectified spirit"

cF St*$*r$ "$rocloric *ci$: -approximately :"= N"

Proce$ure-

&elt the sample, if it is not already liquid, and filter through a filter paper toremoe any impurities and the last traces of moisture" &a!e sure the sample

is completely dry, mix the sample thoroughly, and #eigh by difference about+"= to 6": gm of the sample in a conical flas!" /dd 6= ml of the alcoholicpotassium hydroxide solution #ith pipette and connect the reflux aircondenser to the flas!" *eat the flas! on #ater bath or an electric hot platefor not more than one hour" @oil gently but steadily until the sample iscompletely saponified as indicated by absence of any oily matter andappearance of clear solution" /fter the flas! and condenser hae cooledsome#hat, #ash do#n the inside of the condenser #ith about +: ml of hotethyl alcohol neutral to phenolphthalein" /dd about + ml of phenolphthaleinindicator solution and titrate #ith standard hydrochloric acid" Conduct aparallel blan! determination at the same time"

C*lcul*tios: -

S*poi0ic*tio *lueE =9"+ 0@4(1 N

$

$here,

@ E Aolume of standard hydrochloric acid required for the blan! in ml,

( E Aolume of standard hydrochloric acid required forsample in ml,

N E Normality of the standard hydrochloric acid,and

$ E $eight of the sample of oilfat ta!en in gms"


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3.8.%.3 Io$ie H*lue- 4 Iodine alue is the number of gram of iodineabsorbed by +:: gm of oil or fat" &any methods for its determination are inuse" Out of these $i?s is #idely accepted and recommended method by the@I(" It gies the information about the amount of unsaturation or number ofdouble bonds in a fat sample"

3.8.%.3. *F Deter&i*tio o0 Io$ie *lue G6iKsF

>eer*l: -The material is treated in carbon tetrachloride medium #ith a!no#n excess of iodine mono chloride solution in glacial acetic acid 0$i?ssolution1" The excess of iodine mono chloride is treated #ith potassiumiodide and liberated iodine estimated by titration #ith sodium thiosulphatesolution"

Reagents-

iF Pot*ssiu& Dicro&*te GARF

GiiF. "$rocloric *ci$ - Concentrated

GiiiF. Pot*ssiu& io$i$e solutio4 %repare a fresh solution by dissoling+: gm potassium iodide free from potassium iodate, in : ml of #ater"

GiHF. St*rc solutio 4 Triturate = gm of starch and :":+gm of mercuriciodide #ith >: ml cold #ater and slo#ly pour it #ith stirring into + litre ofboiling #ater" @oil it for three minutes, allo# it to cool and decant off thesupernatant clear liquid"

GHF. St*$*r$ So$iu& Tiosulp*te solutio G.1NF M Dissoleapproximately 67"5 gm of sodium thiosulphate 0Na6 (6O>"=*6O1 in distilled#ater and ma!e up to +::: ml" /nd standardise it as belo#

$eigh accurately about =": gm of preiously dried to a constant #eight at+:= Q 6C potassium dichromate into a clean one litre olumetric flas!"Dissole in #ater, ma!e up to mar!, and sha!e thoroughly" %ipette out 6=ml of this solution into a clean 6=:4ml conical flas!" /dd = ml of conc" *Cland += ml of +: < potassium iodide solution" /llo# it to stand in the dar! for= minutes and titrate the mixture #ith solution of sodium thiosulphate

solution using starch solution as an internal indicator to#ards the end" Theend point is ta!en #hen the blue colour changes to green"

Calculate the normality 0N1 of the sodium thiosulphate solution as bello#

N E 6= $ 7":>A

$here,


29/60

$ E $eight of the potassium dichromate in gm,

A E Aolume of sodium thiosulphate solution required for the titration inml

i1 Glacial acetic acid 4 'ree from alcohol"

ii1 Carbon tetrachloride

iii1 Iodine &onochloride 0 ICl1

ix1 $i?s Iodine &onochloride (oution

Dissole +: ml of iodine monochloride in about +5:: ml of glacialacetic acid and sha!e igorously" %ipette = ml of this solution, add +: ml ofpotassium iodide solution and titrate #ith :"+ N standard sodium

thiosulphate solution using starch solution as an indicator" /d?ust the olumeof the solution till it is approx" :"6 N"

%rocedure -

&elt the sample if it is not already completely liquid, and filterthrough a filter paper to remoe any impurities and the lasttraces of moisture" Use absolutely clean and dry glass#are"$eigh accurately by difference an approx" quantity of the oil orfat bet#een the limits indicated in col" 6 and > of Table4+ into aclean dry 6=:=:: ml iodine flas! or #ell ground glass stoppered

bottle to #hich 6= ml of carbon tetra chloride hae been addedand agitate to dissole the contents" The #eight of the sampleshall be such that there is an excess of =: to 9: percent of $i?ssolution oer that actually needed" /dd 6= ml of the $i?s solutionand replace the glass stopper after #etting #ith potassium iodidesolution, s#irl for intimate mixing and allo# the flas! to stand inthe dar! for >: minutes in the case of non4drying and semidryingoils and one hour in the case of drying oils" Carry out a blan! testsimultaneously under similar experimental conditions" /fterstanding, add += ml of potassium iodide solution and +:: ml of#ater, rinsing in the stopper also, and titrate the liberated iodine

#ith standard thiosulphate solution, s#irling the contents of thebottle continuously to aoid any local excess until the colour ofthe solution is stra# yello#" /dd one millilitre of the starchsolution and continue the titration until the blue colour formeddisappears after thorough sha!ing #ith the stopper on"

T*!le 1- $eight of oil or fat for determination of iodine alue"


30/60

Io$ieH*lue

G1F

Mii&u& 6eito0 s*&ple &

G2F

M*i&u&7eit o0s*&ple &

G3F)ess than > +: +:= =":;; 9">79+: 6"=>57 >"+;>=: :"=655 :"99+6+:: :"6=>5 :">+;>+=: :"+;:: :"6+6=6:: :"+69 :"+=59

C*lcul*tio :-

Io$ie *lue J 12.% G< - SF N

6

$here,

@ E Aolume of standard sodium thiosulphate solution required for theblan! in ml,

( E Aolume of standard sodium thiosulphate solution required for theoil fat sample in ml, and

N E Normality of the standard sodium thiosulphate solution,

$ E $eight of the oil fat sample ta!en for the test in gm"

T*!le 2- %roperties of some commonly encountered Aegetable Oils"#,%

e. Oil Sp.>r*Hit"

3L 3LC

Re0r*ctiHeI$e *t4LC

S*p.*lue

Io$ie

*lue

G6iKsFGroundnut oil

:":4:"+>

+"796:4+"797:

+55 M+=

5; 4 5

Coconutoil

:"+=4:"6:

+"775:4+77:

67=469: ;"=4+:

(esameoil

:"+=4:"+

+"797=4+"799=

+5=4+> +:=4++=

&ustardoil

4444444444444 +"79794+"7999

+94+;; 54++:


31/60

Cottonseed oil

:"+:4:"6:

+"79>:4+"799:

+:4+5 54++6

(oyabeanoil

4444444444444 +"79=:4+7;+:

+54+= +6=4+7:

(unflo#eroil

4444444444444 +"797:4+75::

+554+7 +::4+7:

&ahua oil :"5964:"5;=

+"7=:4+"79+:

+5;4+9 =54;:

Ricebranoil

:"+:4:"6:

+"79::4+"7;::

+5:4+= :4+:=

%alm oil 4444444444444 +"77+4+"7==6

+=46:= 7=4=9

%almolein 4444444444444 +"7==:4+"79+:

+=46:= =7496

Castor oil :"=74:"9:

+"79=4+"7;>:

+;;4+5> 5645

)inseed

oil

:"6>4

:"65

+"7;6:4

+"7;=:

+:4+9 +;:46:6

Re0ereces:

1. &anual of &ethods of Tests and /nalysis for food 0Oils and 'ats1,Directorate General of *ealth (erices, &inistry of *ealth and 'amily$elfare, Goernment of India, Ne# Delhi"

2. (a?id *usain, R" Narsimha, and R" Nages#ara Rao, (eparation,Identification and determination of (anguinarine in argemone and otheradulterated edible oils by reersed4phase high perfomance liquidchromatography, 8ournal of Chromatography /, 59> 0+1, pp"+6> to+69"

3.&ethods of sampling and test for oil and fats, I(- =75 0%art I1, +97"

4. R( Aerma, /B Dalela and .( @abu, 'T4IR (pectrophotometric analysis oforganic explosie formulations, %roceedings of KIII /ll India'orensic (cience Conference, /hmedabad, Gu?rat, from to ++,Noember, 6::+ %% ++;4+79"

#F" Indian (tandard Institutions (pecifications for respectie egetable oils"

%F" &erc! Index" .leenth edition"

OTER RE(ERENCES:

+1" @ulletins of Indian Industrial Research, No" +: , Indian Aegetable Oilsby N" @rodie , +>5"

61" I(- =75 0%art I1 4 +97, &ethods of (ampling and test for oils and fats"


32/60

>1" I(- =75 0%art II1 4 %urity tests"

71" Indian (tandard Institutions (pecifications for respectie egetable oils"

=1" &erc! Index" .leenth edition"


33/60

SECTION - 4

/N/)L(I( O' GO)D OT*.R &.T/)( IN C*./TING C/(.(

4.1. Title - .xamination of Gold and other metals"

4.2. Scope - Gold other metals in crime exhibits"

4.3. Purpose - Sualitatie and quantitatie estimation of Gold"

4.4. Responsibility - Reporting officers and supporting scientif" staff"

4.#. Itro$uctio

Gold is a precious and aluable metal" The human beings are fascinated for

their ornaments" These ornaments are required their maintenance #hichincludes repairing and polishing etc" The criminals often polish the

ornaments #ith polishing po#der and by using aqua4regia solution" The gold

is not soluble in most of the acids, it is soluble in aqua4regia #hich is a

mixture of one part of nitric acid and three parts of hydrochloric acid"

Generally, criminals dupe the house#ies in the name of cleaning and

polishing their ornament and dissole the gold from their ornament in aqua4

regia during the process of cleaning polishing" This aqua4regia solution and

gold etc" sei2ed from the scene of crime by the police are referred to forensic

laboratory under I%C (ection 76:" These exhibits are to be examined in the

laboratory for the analysis of gold" Colour test and modern sophisticated

analytical techniquesmethods, depending upon the nature of samples and

examination, are used for the analysis of samples in the laboratory"

7"9 (ample preparation-

4.%.1.The aqua4regia solution, about 6=: ml from the crime scene should be

sent in glass bottle #ith plastic lid or plastic bottle"

4.%.2. &aterial such as polishing po#ders from the crime scene should bepac!ed in polythene bag and sent to the laboratory"

4.8. Meto$s o0 A*l"sis-

7";"+ Test for aqua4regia -

Test the aqua4regia solution for acidic nature, nitrate ions and chloride ions"


34/60

4.8.1.1 Test0orAci$icN*ture :

*F pP*perTest: &oist the p* paper #ith distilled #ater and impregnate it

#ith exhibit as such or its distilled #ater extract and obsere the p*" p* lessthan ; indicates the presence of acid and more than ; indicates thepresence of al!ali"

/lternate &ethod

*F )it&usP*perTest : &oist the blue litmus paper #ith distilled #ater andimpregnate it #ith exhibit as such or its distilled #ater extract and obserethe colour change of the paper" Colour changing from blue to red indicatesthe presence of acid" If red litmus paper changes to blue, than it indicatesthe presence of al!ali"

4.8.1.2 Test for Chlorie1.2:

*F SilHer Nitr*te Test 1,2: Ta!e the appropriate portion of the exhibit in atest tube and add + drop of nitric acid follo#ed by fe# drops of :"6 & silernitrate solution" / #hite curdy precipitate is obtained #hich is soluble inexcess of ammonium hydroxide solution but insoluble in #ater and dilutenitric acid"

!F Test 6it Sulpuric Aci$3- Ta!e the appropriate portion of the exhibitin a test tube and add fe# drops of conc" (ulphuric acid if required #arm it"

*ydrogen chloride gas is eoled, #hich can be tested by blue litmus paperturns to red or by formation of #hite clouds of ammonium chloride #hen aglass rod moistened #ith ammonia solution is brought near the mouth of testtube"

4.8.3 Test for !itric "ci

4.8.3.1 Test 0or Aci$ic N*ture:

*F pP*perTest: &oist the p* paper #ith distilled #ater and impregnate it#ith exhibit as such or its distilled #ater extract and obsere the p*" %*

less than ; indicates the presence of acid"

/lternate &ethod

!F )it&us P*per Test: &oist the blue litmus paper #ith distilled #ater andimpregnate it #ith exhibit as such or its distilled #ater extract and obserethe colour change of the paper" Colour changing from blue to red indicatesthe presence of acid"


35/60

4.8.3.2 Test 0or Nitr*te: Depending upon the nature of exhibits andaailability of resources, any one of the follo#ing methods can be used forthe detection of nitrate" Ta!e the appropriate portion of the exhibit in abea!er add distilled #ater, sha!e #ell and filter it" The filtrate may be usedfor performing the tests"

*F Ri Test3: 0i1 /dd about > ml of a freshly prepared saturated solutionof ferrous sulphate to about 6 ml of the nitrate solution 0filtrate of theexhibit1 in a test tube and pour >4= ml conc" sulphuric acid slo#ly do#n theside of the test tube so that acid forms a layer beneath the mixture" /bro#n ring #ill form #here the liquids meet #hich indicates the positie testfor the presence of nitrate"

0ii1 /dd about 7 ml of conc" sulphuric acid slo#ly to about 6 ml of the nitratesolution 0filtrate of the exhibit1 in a test tube and mix the liquids thoroughlyand cool the mixture in tap #ater" No# a saturate solution of ferrous

sulphate in added slo#ly do#n the inner side#all of the test tube to form alayer on the top of the liquid" 'ormation of a bro#n ring at the ?unction oft#o liquids indicates the presence of nitrate"3

!F Dipe"l*&ie Re*et Test3:To a small amount of diphenylaminereagent 0dissole :"= gm" Of diphenylamine in 5= ml conc" sulphuric acid anddilute to +:: ml #ith #ater1 in a test tube add a small portion of the filtratecarefully to the side of the test tube, a blue ring at the ?unction indicates thepresence of nitrate"cF (errous Sulp*te Test4 : To a drop of filtrate on a spot plate add acrystal of ferrous sulphate 0pin head1, a drop of conc" sulphuric acid is

allo#ed to run in at the side" In the presence of nitrate, a bro#n ring isformed around the ferrous sulphate crystal"

$F


36/60

4.8.2.1 Tests 0or *&&oiu& ios:

a1 Nessler Reagent Test 7-

Ta!e one drop of test sample or extract, add one drop of conc" NaO* solution

0=gms in = ml #ater13 on a #atch glass or in a small test tube" Ta!e out amicro drop from this and !ept on a filter paper and add to it one drop ofNessler reagent" /ppearance of a yello# or orange red stain or ring indicatesthe positie test for the presence of ammonium ions"

Prep*r*tio o0 Nessler re*et 3-

(olution +- Dissole +: gms of BI in +: ml of #ater"

(olution 6- Dissole 9 gms of mercury 0II1 chloride in +:: ml of #ater"

(olution >- Dissole 7= gms of NaO* in #ater and dilute to 5: ml"

No# add solution 6 to solution + drop #ise until a slight permanent ppt" isformed then add solution >, mix and dilute #ith #ater to 6:: ml" Beep it foroernight and decant the clear solution" The solution may be used for onemonth"

!Fta!e an appropriate amount of the suspected sample , add to it fe# dropof NaO* solution in a test tube and heat it" (mell of ammonia is obsered"This can be confirmed by bringing a glass rod dipped in *Cl acid on themouth of the test tube" $hite fumes are produced"%

4.8.2.2 Test 0or Clori$e1.2:

*F SilHer Nitr*te Test:Ta!e the appropriate portion of the exhibit in abea!er add distilled #ater, sha!e #ell and filter it" Ta!e fe# ml" of thefiltrate in a test tube and add + drop of nitric acid follo#ed by fe# drops of:"6 & siler nitrate solution" / #hite curdy precipitate is obtained #hich issoluble in excess of ammonium but insoluble in #ater and dilute nitric acid"

!F Test 6it Sulpuric Aci$: /s mentioned under section 6"="+"6 b"

4.8.2.3 Test 0or Sulp*te#.$:

*F


37/60

*FRo$i9o*te Test3: ta!e a drop of barium chloride solution 0:"6=& M9+"+ g barium chloride dihydrate diluted in + litre of #ater1 on a filter paperand add a drop of fresh solution of sodium rhodi2onate 0=


38/60

Alter*teMeto$o0(l*&eTest11

Ta!e a platinum or nichrom #ire and #et it #ith conc" *ydrochloric acid andheat it in the non4luminous flame of the burner until the yello# colour of theflame disappears" Dip the #ire into test exhibit solution as such or its

distilled #ater extract 0or po#der if exhibit is solid1 and heat it in the non4luminous flame of the burner" Obsere the color of the flame as aboe" /persistence golden yello# flame indicates the presence of sodium"

4.8.2.# Test 0or Pot*ssiu& ios:

iF Dipicr"l*&ie Re*et Test 4:

%repare a drop reaction paper by soa!ing the filter paper in sodiumdipicrylaminate reagent 0:"6 g dipicrylamine in 6 ml of 6N sodium carbonateand += ml #ater1 and dried in a blast of heated air"

%lace a drop of neutral test solution on the drop reaction paper, dry it in acurrent of hot air" Beep the paper in :"+N nitric acid" 'ormation of red flec!or ring at site of the spot indicates the positie test for the presence of%otassium"

iiF (l*&e Test: %otassium gies iolet color #hen it is tested by flame testas described in the testing of sodium"

4.8.2.% Test 0or Copper:

iF Test 7it *&&oiu& "$roi$e

Ta!e the test sample solution 0dissole the sample in #ater or dil *cl or conc"*Cl or dilconc" *NO>or aqua4regia to form original solution1 and add to itammonium hydroxide" /ppearance of blue color indicates the positie testfor the presence of Copper"

iiF Test 7it Ali9eri !lue 4:

Ta!e a drop of reagent 0saturated solution of ali2erin blue in pyridine1 in adepression spot plate and add to it a drop of test solution" Run a parallel

blan! test #ith #ater also" @lue color appears in both the cases" No# add +46drops of acetic anhydride, the color in the blan! test conerts into yello# butremaining of blue4iolet precipitate in test sample indicates the positie testfor the presence of Copper"

Alter*te Meto$:


39/60

Ta!e +46 drops of test solution in depression spot plate and eaporate it todryness" /dd a drop of the reagent and follo#ed by a drop of glacial aceticacid" /ppearance of blue4iolet color indicates the positie test for thepresence of Copper"

iiiF (l*&e Test: Copper gies bluish green color #hen it is tested by flametest as described in the testing of sodium"

4.8.2.8 Test 0or Iro

iF Test 7it Pot*ssiu& 0erroc"*i$e:

Ta!e fe# drops of test solution or original solution, add to it a drop of conc"Nitric acid and boil for fe# minutes" /dd %otassium ferrocyanide solution"/ppearance of blue color indicates the positie test for the presence of Iron"

iiF Test 7it tioc"**te %:

Ta!e fe# drops of test solution or original solution, add to it a drop of conc"Nitric acid and boil for fe# minutes" /dd ammonium or potassiumthiocyanate solution" /ppearance of red color indicates the positie test forthe presence of Iron"

The aboe tests can be performed on filter paper or spot tile as belo# 4

%ut a drop of test solution on a filter paper or spot plate, add to it a drop of%otassium ferrocyanide solution" /ppearance of blue color on paper or plate

indicates the positie test for the presence of Iron"

%ut a drop of test solution on a spot plate, add to it a drop of potassiumthiocyanate solution 0+


40/60

4.8.3.1. Test %ith &en'iine( : 'e# drops of the exhibit solution isplaced on a filter paper and add +46 drops of ben2idine reagent solution onit" / blue colour appears on the filter paper, #hich indicates the presence ofgold"

Re*et::":=< solution of ben2idine in +:< acetic acid

4.8.3.2. Test %ith Rhoamine &( : 'e# drops of the exhibit solution isplaced is ta!en in a micro test tube and add one4t#o drops of *Cl acid and +46 drops of rhodamine @ reagent solution and mix properly" The test tube issha!en #ith about 54+: drops of ben2ene" /ppearance of red4iolet to pin!colour in ben2ene layer indicates the presence gold" /fter about +46 minutesit displays an orange fluorescence if it is obsered under quart2 lamp"

Re*et:

+1 :":+ g" rhodamine @ dye stuff in +:: ml #ater

61 :"6< aq" rhodamine @ solution 0gien under detection of gold in alloys,coating etc"1 the sensitie and specific test for gold #ith rhodamine @"

4.8.3.3. Test %ith )*alic "ci$ : /n appropriate portion of the exhibitgenerally heated till NO6 fumes remoed" This solution is made al!aline byadding sodium hydroxide solution" (olid oxalic acid #as added andgenerally heated" @ro#nish blac! precipitate indicates the presence of gold"

4.8.3.4 Ti l*"er cro&*tor*p" 0or ol$ 13:

The gold can be detected by T)C technique #hich inoles the gold in0*/uCl7>*6O1 form free from nitrate ions is spotted on T)C plate along #ithstandard gold soln and then the T)C plate is run in solent system of@en2ene- @utanol- /cetic acid 0>"=- 7"=- +1" The plate is then sprayed #ith =>74>>=, >>9, >67, >>9, =5=, =;,>794>7;, >75

7" 'rit2 feigl, (pot tests in inorganic analysisP, =thedition, +=, p">69, >654>6, +65, +6, 6>5, 6>6, >, +9+, +97,"

=" Gurudeep *arish, %ractical Inorganic Chemistry, 9 th edition, +5545,pp"+=>"

9"(ubhash4(atish, / hand boo! of analytical chemistry, +>thedition, +;54

;, pp 6

;" /nalytical Chemistry by (" (hapiro La" Gurich, &IR %ublishers, &osco#,+;6, pp"9>497

5" /nalytical Chemistry by (" (hapiro La" Gurich, &IR %ublishers, &osco#,+;6, pp"=>;


42/60

" (pot test in inorganic analysis by 'rit2 'eigl, fifth edition, .lseier%ublishing Company, Netherlands, +=5, pp" 6>:"

+:" Aogels text boo! of macro and semi4micro qualitatie inorganic analysisby G" (ehla, =thedition, )ongman Group )imited, Great @ritain, +;, pp"

79=499"

++" /nalytical Chemistry by (" (hapiro La" Gurich, &IR %ublishers,&osco#, +;6, pp"9="

+6" &"Thompson and 8"N"$alsh, / hand boo! of Inductiely Coupled %lasma(pectrometry, +5>

+>" R"@" %udale et" al" T)C method for the detection and(emiquantitatie determination of gold in forensic #or!,%roceeding of K th /ll India 'orensic (cience conference,

@hubanes#ar, +;"

+7" / textboo! of Suantitatie Inorganic /nalysis by Aogel" 6nd edition ,+=+"

+=" &"Thompson and 8"N"$alsh, / hand boo! of Inductiely Coupled %lasma(pectrometry, +5>

SECTION - #

ACIDS + A)A)IS

#.1. Title - .xamination of corrosie chemicals li!e hydrochloric acid,sulphuric acid, and nitric and al!alies in crime exhibits of acidal!ali thro#ingcases"

#.2. Scope - Crime exhibits containing corrosie chemicals"

#.3. Purpose - To detect the presence of hydrochloric acid, sulphuric acid,nitric acid and al!alies in crime exhibits"

#.4. Responsibility - Reporting officers and supporting scientific staff"

#.#. ethos - The follo#ing methods are to be used for the detection ofthe constituents of the hydrochloric acid, sulphuric acid and nitric acid in thecrime exhibits"


43/60

#.#.1 Test for /yrochloric "ci

#.#.1.1 Test for "ciic !ature:

*F p/ Paper Test : &oist the p* paper #ith distilled #ater and

impregnate it #ith exhibit as such or its distilled #ater extract andobsere the p*" p* less than ; indicates the presence of acid and morethan ; indicates the presence of al!ali"

/lternate &ethod

!F 0itmus Paper Test: &oist the blue litmus paper #ith distilled #aterand impregnate it #ith exhibit as such or its distilled #ater extract andobsere the colour change of the paper" Colour changing from blue tored indicates the presence of acid" If red litmus paper changes to blue,than it is indicates the presence of al!ali"

#.#.1.2 Test for Chlorie1: Ta!e the appropriate portion of the exhibit ina bea!er add distilled #ater, sha!e #ell and filter it" Ta!e fe# ml" of thefiltrate in a test tube and add + drop of nitric acid follo#ed by fe# drops of:"6 & siler nitrate solution" / #hite curdy precipitate is obtained #hich issoluble in excess of ammonium hydroxide solution"

#.#.2 Test for Sulphuric "ci


*Fp/ Paper Test: &oist the p* paper #ith distilled #ater and impregnateit #ith exhibit as such or its distilled #ater extract and obsere the p*"%* less than ; indicates the presence of acid"

/lternate &ethod

!F 0itmus Paper Test : &oist the blue litmus paper #ith distilled #aterand impregnate it #ith exhibit as such or its distilled #ater extract andobsere the colour change of the paper" Colour changing from blue to redindicates the presence of acid"

#.#.2.2 Test for Sulphate1: Ta!e the appropriate portion of the exhibit ina bea!er add distilled #ater, sha!e #ell and filter it" Ta!e fe# ml" of thefiltrate in a test tube and add fe# drops of concentrated hydrochloric acidfollo#ed by:"6= & barium chloride solution" $hite precipitate indicates thepresence of sulphate"

#.#.3 Test for !itric "ci


44/60


!F p/ Paper Test: &oist the p* paper #ith distilled #ater and impregnateit #ith exhibit as such or its distilled #ater extract and obsere the p*"%* less than ; indicates the presence of acid"

/lternate &ethod

!F 0itmus Paper Test : &oist the blue litmus paper #ith distilled #aterand impregnate it #ith exhibit as such or its distilled #ater extract andobsere the colour change of the paper" Colour changing from blue to redindicates the presence of acid"

#.#.3.2 Test for !itrate: Depending upon the nature of exhibits andaailability of resources, any one of the follo#ing methods can be used forthe detection of nitrate" Ta!e the appropriate portion of the exhibit in a

bea!er, add distilled #ater, sha!e #ell and filter it" The filtrate may be usedfor performing the tests"

a Ring Test2:

0i1 /dd about > ml of a freshly prepared saturated solution of ferroussulphate to about 6 ml of the nitrate solution 0filtrate of the exhibit1 in a testtube and pour >4= ml conc" sulphuric acid slo#ly do#n the side of the testtube so that acid forms a layer beneath the mixture" / bro#n ring #ill form#here the liquids meet #hich indicates the positie test for the presence ofnitrate"

0ii1 /dd about 7 ml of conc" sulphuric acid slo#ly to about 6 ml of the nitratesolution 0filtrate of the exhibit1 in a test tube and mix the liquids thoroughlyand cool the mixture in tap #ater" No# a saturate solution of ferroussulphate in added slo#ly do#n the inner side#all of the test tube to form alayer on the top of the liquid" 'ormation of a bro#n ring at the ?unction oft#o liquids indicates the presence of nitrate"

cF iphenylamine Reagent Test2 : To a small amount of diphenylaminereagent 0dissole :"= gm" Of diphenylamine in 5= ml conc" sulphuric acidand dilute to +:: ml #ith #ater1 in a test tube add a small portion of the

filtrate carefully to the side of the test tube, a blue ring at the ?unctionindicates the presence of nitrate"

c 3errous Sulphate Test# : To a drop of filtrate on a spot plate add acrystal of ferrous sulphate 0pin head1, a drop of conc" sulphuric acid isallo#ed to run in at the side" In the presence of nitrate, a bro#n ring isformed around the ferrous sulphate crystal"


45/60

$F &rucine Test#: To a fe# drop of filtrate, a solution of brucine 0:":6>74>>=, >794>7;, >>9"

3. 'rit2 feigl, (pot tests in inorganic analysisP, =th edition, +=,p">69, >654>6"

SECTION - %

E@AMINATION O( CEMICA)S =SED IN TRAP CASES

%.1. Title - .xamination of chemicals used in Trap Cases"

%.2. Scope: %henolphthalein, anthracene, sodium carbonate and calciumhydroxide in crime exhibits"


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47/60

The hand #ashings, bag #ashings, cloth #ashings etc of the suspectcollected in dilute sodium carbonate4#ater solution or lime #ater along #ithother releant articles from the scene of crime such as currency notes,clothes, bags etc shall be sent to the laboratory for the chemicalexamination"

%.%.1.1. In case of untreated ob?ects, ethyl alcoholic #ash extract of theappropriate portion of the exhibits can be ta!en for the examination for thedetection of the phenolphthalein" /lternatiely, dilute solution of al!ali0sodium carbonate1 in #ater can also be used for #ashingextracting theexhibits" These #ashing shall be used only for the detection of thephenolphthalein and not for the detection of the sodium and carbonate ions"

%.%.1.2. In case of al!ali treated ob?ects, #ash the appropriate portion of theexhibits #ith #ater and used for the detection of the phenolphthalein,sodium and carbonate ions etc"

%.%.2. Atr*cee:

/rticles from the scene of crime such as currency notes, clothes, bags etcalong #ith traces of po#der collected by carefully brushing the suspectedarea of contact of accused shall be sent to the laboratory for theexamination"

%.%.2.1. In case of the ob?ect of anthracene, the appropriate portion of theob?ect exhibit 0after examination under u"" light1 can be #ash #ith ethylalcohol for the examination"

%.8. Det*ils o0 te Meto$s o0 **l"sis :

The follo#ing methods can be used for the examination of the trap case forthe detection of required constituents depending upon the case historynature of the examination of the case"

%.8.1. Test 0or Peolpt*lei :

%.8.1.1. Color Tests :

%.8.1.1.1. p Test2,3:

Obsere the p* of the solution exhibit #ith the p* paper" &ore than p* 0p*range 5">4+:1 #ith pin! red color indicates the positie test for the presenceof phenolphthalein"

%.8.1.1.2. Aci$ Al5*li Test3, 4:


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Ta!e an appropriate portion of the exhibit solution" /dd fe# drops dilutehydrochloric acid" The pin! color of the exhibit disappears" No# add fe#drops of dilute solution of sodium hydroxide in #ater, the pin! colorreappears" If required, this test can also be performed on residue obtainedafter eaporation of ethanol extract of the exhibit, but in this case first add

al!ali solution and then acid"

/ppearing and disappearing of pin! color indicates the positie test for thepresence of phenolphthalein"

%.8.1.2. Etr*ctio#46:

Ta!e appropriate amount of the exhibit solution" &a!e the solution acidic#ith the addition of dilute hydrochloric acid drop #ise #ith stirring till p*about 7 to = 0alternatiely till acidic to congo red1" .xtract #ith 6:46= ml" ofsolent ether t#o times and eaporate to concentrate and used for other

tests" The ether extract can also be eaporated to dryness and the residuecan be dissoled in ethanol, #hich can be used for other tests"

%.8.1.3. Thin 0ayer Chromatography:

(tationary phase - T)C plate coated #ith silica gel G or silica gel G '6=7"

&obile phase - /ny one of the follo#ings-4

+" @en2ene, Dioxan and acetic acid 0;=-+=-:"=1%

6" Chloroform and /cetone 0 5:-6:18

>" .thyl acetate, &ethanol and (trong /mmonia 06; to >:


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Ta!e a portion of the exhibit solution, filtered and scan to note its lmaxabsorbance alue by spectrophotometer in appropriate dilution using astandard solution of phenolphthalein in aqueous al!ali 0sodium carbonate1for comparison" The pin! color of phenolphthalein in aq" (odium carbonatesolution gies the lambda max in bet#een around ==:4=== nm. /queous

solution of sodium carbonate is used as blan! solution for the experiment"

Other instrumental techniques li!e *%)C, 'TIR, GC4&( are also being used forthe detection of %henolphthalein"

%.8.1.#. Alter*teTest0orPeolpt*lei:

3olin,Cioc*lteusre*ettest#:

Ta!e about + ml of alcoholic extract of the exhibit obtained as per requiredextraction procedure" /dd I ml of folin Mciocalteu reagent follo#ed by 6 ml of

6:< sodium carbonate solution" @lue color indicates the positie test for thepresence of phenolphthalein"

%.8.2. Test 0or Atr*cee :

%.8.2.1.Color Test :

Obseration under u"" light M Aioletbluegreen fluorescence"

%.8.2.2.Ti )*"er Cro&*tor*p";:

(ample preparation - In ethyl alcohol

(tationary phase - (ilica gel G

&obile phase - 0/ny t#o1

+" *eptane6" *exane>" Carbon tetrachloride Aisuali2ation - +" U"A" light

6" 'ormaldehyde4(ulphuric acid reagent

0:"6 ml of >;< formaldehyde solution in +: ml of conc" (ulphuric acid1

A)TERNATE METODS

%.8.2. Sep*r*tio *$ puri0ic*tio o0 Atr*cee 0ro& sei9e$&*teri*l:


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Currency notes, shirts, pant, hand!erchiefs, diaries, boo!s etc in anti4corruption casesbribe trap cases collected oer a year #ere examined along #ith commercial anthracene by T)C technique using Chloroformdeeloping solent" The suspected portion after locating under UA lamp ofeery exhibit #as initially extracted in ethanolether, then sub?ected to

T)CG)C examination"

%.8.2.1. T/+! 0"5-R C/R)"T)GR"P/5:

(ample preparation - In ethyl alcohol 3=<

(tationary phase - (ilica gel G 3/ctiated at ++:: C for + hour

&obile phase - Chloroform

Aisuali2ation - +" U"A" light

%.8.2.2 = Spectrophotometry:

The separated spot of the analyte corresponding to reference spot ofanthracene #as scrapped off from the preparatie T)C" To the scrappedsilica gel appropriate amount of ethanol #as added" 'iltered or decanted it"Concentrate the filtrate to appropriate olume" @lan! #as similarly preparedfrom the silica gel scrapped off from the same plate" The filtrate #assub?ected to U A spectroscopic study" /lternatiely the exhibit cab also beextracted #ith =< of ethanol and sub?ected to U A (pectroscopy study" /control sample of anthracene in ethanol cab be used as a standard sample

for comparison of U A (pectrum"

%.8.2.3 >*s )iui$ Cro&*tor*p":

Detector - 'lame ioni2ation

Column - ( ( column +5 inch dia" 6 meter length

%ac!ing - +:< ( . >: 5:+:: chromosorb $4*%

Carrier Gas - Nitrogen

'lo# rate - 6= mlmin

In?ector temperature - 6=::C

Column temperature - 66::C Isothermal

Detector temperature - 6=::C


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Ta!e a portion of exhibit solution and ma!e it neutrali2ed #ith acetic acid"/dd fe# drops of uranyl 2inc acetate reagent, sha!e stir #ith glass rod"'ormation of yello# precipitate or cloudiness indicates positie test for thepresence of sodium"

Preparation of uranyl 'inc acetate12

:

Ta!e +: gms of uranyl acetate in ==ml of #ater, >: gms of 2inc acetate, and ml of acetic acid" *eat to dissole and dilute #ith #ater to ma!e up to +::ml" /llo# to stand for 67 hours, and filter"

"0T-R!"T- -T/) 3)R T/- PR-P"R"T+)! )3 9R"!50 +!C"C-T"T-R-"G-!T13:

Solutio A:

Ta!e +: grams uranyl acetate in 9 gms of >:< acetic acid" If necessary#arm it, dilute #ith distilled #ater to =:ml "

Solutio : grams 2inc acetate is stirred #ith >gms >:< acetic acid anddilute it #ith distilled #ater to =: ml" &ix the aboe t#o solutions / and @"$arm if required" /dd a trace of sodium chloride, !eep it for 67 hours andfiltered" 'iltrate is used as aboe reagent"

%.8.#. Test for Calcium

Test 7it So$iu& Ro$i9o*te14:

Ta!e one drop of neutral or #ea!ly acid test solution add a drop of freshlyprepared :"6< a sodium rhodi2onate solution add one drop of :"= N sodiumhydroxide solution, a iolet colour indicates the presence of calcium"

Alter*te Meto$s 0or So$iu& + C*lciu&:

3lame test1$:

Ta!e appropriate portion of the exhibit as such or its #ater 0distilled1 extracteaporate to dryness, moisten #ith a fe# drops of conc" *ydrochloric acid to

ma!e past" Ta!e a small portion of paste #ith the platinum #ire andintroduce into the non4luminous flame of a semi4micro burner" / persistencegolden yello# flame indicates the presence of sodium and a bric! red0yello#ish red1 flame indicates the presence of calcium"

"lternate etho of 3lame Test16


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Ta!e a platinum or nichrom #ire and #et it #ith conc" *ydrochloric acid andheat it in the non4luminous flame of the burner until the yello# colour of theflame disappears" Dip the #ire into test exhibit solution as such or itsdistilled #ater extract 0or po#der if exhibit is solid1 and heat it in the non4luminous flame of the burner" Obsere the colour of the flame as aboe"

R-3-R-!C-S:

+" Organic Chemistry Aolume + The 'undamental %rinciples by I")" 'innar, 9thedition, The .nglish )anguage @oo! (ociety and )ongman Group )imited,)ondon, +;>, pp" 5+7"

6" The &erc! Index ++thedition by (usan @udaari, %ublished by &erc! Co"Inc", Rah#ay, U(/, +5, pp"+:5 0/cc" No">7:71"

>" Aogels Text @oo! of Suantitatie Inorganic /nalysis, 7thedition, by 8"

@assett, R"C" Denney, G"*" 8effery, 8" &endham, .nglish )anguage @oo!(ociety )ongman, Great @ritain, +59, pp" 67+

7" The &erc! Index ++thedition by (usan @udaari, %ublished by &erc! Co"Inc", Rah#ay, U(/, +5, pp"++=: 0/cc" No">7:71

=" Isolation and identification of drugs by ."G"C" Clar!e, ol"+, Thepharmaceutical %ress, )ondon, +;7, pp"755 0/cc" No"+>6=1"

9" @rea! do#n products of phenolphthalein in al!ali media by B"Narayans#amy, B"(" Chhara, @" &andal *")" @ami, 'orensic (cience

08ournal1, +;5, Aol"+; No"6, pp"647"

7" Clar!es Isolation and Identification of Drugs by /"C" &offat,second edition, The pharmaceutical %ress, )ondon, +59, pp" 55= +950/cc" No">5+1"

5" Thin )ayer Chromatography by .gon (tahl, second edition, George /llen Un#in )td", )ondon, +9, pp"995499 0/cc" No"=51"

" 'orensic .xamination of /nthracene Traces on (ei2ures in /nticorruptionOffence by T)C, UA and G)C Techniques by / G @hoi and B / /mbade,

8ournal of Indian /cademy of 'orensic (ciences 0++1 %age no" + to 69"

+:" Aogels text boo! of macro and semi4micro qualitatie inorganic analysisby G" (ehla, =thedition, )ongman Group )imited, Great @ritain, +;, pp"654>:+ 0/cc"No6>=;1"

++" /nalytical Chemistry by (" (hapiro La" Gurich, &IR %ublishers,&osco#, +;6, pp"9>497


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+6" /nalytical Chemistry by (" (hapiro La" Gurich, &IR %ublishers,&osco#, +;6, pp"=>;

+>" (pot test in inorganic analysis by 'rit2 'eigl, fifth edition, .lseier%ublishing Company, Netherlands, +=5, pp" 6>: 0/cc"No">>1"

+7" (pot test in inorganic analysis by 'rit2 'eigl, fifth edition, .lseier%ublishing Company, Netherlands, +=5, pp" 666466> 0/cc" No" >>1"

+=" Aogels text boo! of macro and semi4micro qualitatie inorganic analysisby G" (ehla, =thedition, )ongman Group )imited, Great @ritain, +;, pp"79=499"

+9" /nalytical Chemistry by (" (hapiro La" Gurich, &IR %ublishers,&osco#, +;6, pp"9="


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Sectio - 8

/N/)L(I( O' /)CO*O) IN )ISUOR(DRINB(

8.1. Title - /nalysis of alcohol in liquorsdrin!s"

8.2. Scope - /nalysis of arious types of alcoholic drin!sliquor in crimeexhibits"

8.3. Purpose - Sualitatie and quantitatie estimation of ethyl alcohol inarious alcoholic preparations"

8.4. Responsibility- Reporting officers and supporting scientific staff"

8.#. Itro$uctio

)iquor is normally !no#n as a mixture of #ater and alcohol" The termalcohol is often used for ethyl alcohol" The liquor is manufactured by thefermentation process in #hich carbohydrates are fermented in presence ofen2ymes as per their specifications gien in @ureau of Indian (tandards0@I(1" Country made liquor is alcoholic product usually prepared fromfermentation of carbohydrates present in cereals, ?aggery, fruits, mahua,palm, molasses etc" The liquors are sold in the mar!et in arious brands andcoered under .xcise /ct" The possession, sale, transportation of liquor isallo#ed only as per the Rules and Regulations of .xcise and %rohibition"&any times these liquors are being smuggled from one (tate to another

(tate, illegal possession, transported #ithout proper alid documents" Thesesamples are sei2ed by the %olice and submitted to the 'orensic )aboratoryfor their examination" The liquor is examined in the laboratory for t#opurposes firstly, for .xcise purpose #here, mainly the presence of alcoholplays an important role and accordingly the examination of liquor samplesfor the qualitatie and quantitatie analysis is the main purpose of theinestigation" (econdly, the liquor is examined for quality controlduplicatesamples, #hich are being sold in the mar!et in #hich the examination iscarried out for other parameters also apart from alcohol contents" Thealcohol contents are also reported in percentage of proof spirit, percentageof alcohol 0#eight by olume1 and percentage of alcohol 0olume by olume1"

8.%. ethos :

8.%.1 ;ualitati8e "nalysis of 0i


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57/60

8.%.1.3 Test for Copper = +ron(: Ta!e about = ml or appropriate amountof sample add + drop of Nitric acid and + ml of :":6= & potassium'errocyanide solution" %russian blue colour indicates presence of iron andchocolate colour indicates the presence of copper"

8.%.1.4 Test for 3urfural#

:Ta!e about = ml or appropriate amount ofsample 0distilled or as such depending upon the nature of sample andconcentration of furfural1 in a test tube, add about + ml aniline and about:"= ml hydrochloric acid and !eep it for += minutes" /ppearance of redcolour indicates the presence of furfural"

"lternati8e metho for testing furfural:

*FTa!e about 6 ml or appropriate amount of the sample distilled or as suchdepending upon the nature of sample in a test tube, add about :"6 ml ofaniline and about :"7 ml of glacial acetic acid" If the furfural is present in the

sample, red colour deelops in a fe# seconds reaches its maximumintensity in =4+: minutes#"

!FTa!e about 6 ml or appropriate amount of the sample distilled or as suchdepending upon the nature of sample in a test tube, add about + ml ofaniline acetate solution 0+:< AA solution of aniline in glacial acetic acid1"/ppearance of red colour indicates the presence of furfural" The colourdeelops at room temperature of 6=4>::C and reaches its maximumintensity in +4= minutes%"

8.%.2. ;uantitati8e "nalysis of 0i9 and find out thequantity of alcohol 0< of proof spirit and < of alcohol AA1 from the tablesho#ing the relation bet#een the specific graity of spirits at 9::9::' andthe percentage of ethyl alcohol by #eight and by olume #ith thecorresponding percentage of proof spirit issued under the authority of theCommissioner of *er &a?estys Customs and .xcise, )ondon, *er &a?estysstationery office +==, Reprinted +;+"


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.xample of Calculation- /t temperature of ;9:' 067"=oC 1'ECK+"5Q>6E8%.1o(

+" $eight of =: ml specific graity bottle - 69"95;: gm6" $eight of bottle plus distilled #ater - ;9"9;6: gm

>" $eight of #ater - ;9"9;6:469"95;: E 7"5=: gm7" $eight of +::: ml #ater - 7"5=: x 6: E "; gm 041=" Temperature correction - +"97 0to be added1 at ;9o'9" $eight of + liter #ater - "; Q +"97 E +::+">7;" @ottle correction - +::+">7 M +::: E +">7Q5" $eight of exhibit and bottle - ;>"56=: gm" $eight of the exhibit - ;>"56=: M 69"95;: E 7;"+>5 gm+:" $eight of the +::: ml exhibit - 7;"+>5 x 6: E 76";9 gm++" $eight of exhibits #ith bottle correction - 76";9 M +">7 E 7+"76gm+6" Temperature correction - 9":: 0at ;9:'1

+>" Corrected #eight of the exhibit - 7:"79 Q 9"::E 79"79 gm+7" (pecific graity of the exhibit - 79"79+::: E :"7979+=" %ercentage of proof spirit - ;="9+9" %ercentage of alcohol AA - 7>"6=

"0T-R"!"T+>- -T/)S 3)R -T/50 "0C)/)0:

G*F Gas Chromatography1:

)perating conitions :,

Column - %orapac! polymer bead 5:4+:: mesh or its equialent, #hich canseparateresole the ethanol

Column Temperature - +9::C

Carrier Gas - Nitrogen Gas

Rate of gas flo# - =: mlmin

Detector - 'ID 0'lame Ioni2ation Detector1

"lternati8e )perating Conitions?:

Column - :">< Carbo#ax 6: & on 5:4+:: mesh Carbopa! C, 6m x 6mm ID orits equialent

Column Temperature - >=:C for 6 minutes and then programmed at =:C perminute to +;=:C and hold for at least 5 minutes


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Carrier Gas - Nitrogen at >: mlmin

G!F The percentage 0contents1 of the alcohol can also be found from thetable gien in Official &ethods of /nalysis of the /ssociation of Official/gricultural Chemists 0/"O"/"C"1;after calculating the specific graity of the

liquor samples"

8.%.2.2. etermination of ethyl "lcohol:

Gas Chromatography1:

)perating conitions :,

Column - %orapac! polymer bead 5:4+:: mesh or its equialent, #hich canseparateresole the ethanol

Column Temperature - +9::

C

Carrier Gas - Nitrogen Gas

Rate of gas flo# - =: mlmin

Detector - 'ID 0'lame Ioni2ation Detector1

"lternati8e )perating Conitions?:

Column - :">< Carbo#ax 6: & on 5:4+:: mesh Carbopa! C or its equialent

Column Temperature - >=: for 6 minutes and then programmed at =: perminute to +;=:and hold for at least 5 minutes

Carrier Gas - Nitrogen at >: mlmin

8.%.2.3 )ther eterminations: The follo#ing determinations 0some or alldepending upon the nature of examination and infrastructure aailable1, ifrequired, may be carried out as per I(->;=6-+55"

iF Determination of ash

iiF Determination of total acidityiiiF Determination of olatile acidityiHF Determination of fixed acidityHF Determination of residues on eaporationHiF Determination of estersHiiFDetermination of higher alcoholsHiiiFDetermination of aldehydesiF Determination of copper


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F Determination of furfural

References:+" /rthor I Aogel, / text boo! of practical organic chemistryP,>rdedition, +=9, page +:954+:9

6" (#arup Narain Ti#ari, /nalytical Toxicology, @ureau of %olice Research deelopmentP +;9, %age 6:6+

>" I( >;=6 +55 Indian (tandard /lcoholic Drin!s M &ethods of Test, 'irstReision7" G" (ehla, Aogels text boo! of &acro and (emi4micro qualitatieinorganic analysisP, =thedition, +;, %age 6+5 679=" I( - >6> M +=, Indian (tandard specification for rectified spirit, Reised,th Reprint December, +5, page 65469" %"(" Ra?u and ("&" Chatter?ee, / (pectrophotometric &ethod fordetermining furfuraldehyde in illicit liquorsP, 8ournal of Indian /cademy of

'orensic (cience, Aol"7, No"+, 8an", +9=;" /"C" &offat et"al, Clar!es Isolation and Identification of DrugsP" The%harmaceutical %ress, )ondon, 6nd.dition, +59"

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