Trn trng bit n:

M uNc l ti nguyn ph bin nht trn tri t che ph khong 71% b mt tri t (khong 361 triu m3) tr lng nc c c tnh khong 1,5 t m3. Trong nc ngt ch chim 28,25 triu km2(1,88% thy quyn). Nc ng ngha vi s sng,n l thnh phn chnh ca cc vt th sng. ngi nc chim t 60 n 70% trng lng c th, trong mt s loi sinh vt bin c khi lng nc ln ti 90%. Nc tham gia vo thnh phn sing quyn v iu ho cc yu t kh hu, t ai, sinh vt ...Thng qua chng trnh vn ng ca n.

Cng vi s pht trin ca vn minh nhn loi, nhu cu nc ngy cng ln. Hin ti ton b lng nc s dng trong sinh hot, cng nghip v nng nghip, lng nc s dng cho nhu cu ny thi ra ngy cng ln, gy nhim ng k n ngun nc v mi trng. Nc thi a vo nc cc loi ho cht khc nhau, t trng thi tan hoc huyn ph, nh tng n cc loi vi khun. Mt khc khi thi vo nc do tng tc ho hc ca cc cht m to nn cc cht mi ngn cn qu trnh lm sch nc v nh hng n s sng ca cc sinh vt trong nc.

Qu trnh th ho, cng nghip v nng nghip ho thm canh cng pht trin th tnh trng nhim ngun nc mt, nc ngm xut hin nhiu nc, nhiu ni v ngy cng tr nn nghim trng. S nhim nc khng ch n thun l do vi sinh vt v cc cht hu c d phn hu, m cn do nhiu cht hu c khc, cc sn phm du, cc cht ty ra cc cht phng x... l cc cht c hi gy nguy him cho sc kho con ngi v mi sinh vt sng. Trn gc mi trng phenol v cc dn xut ca phenol c xp vo loi cht gy nhim. y l nhm tng i bn , c kh nng tch lu trong c th sinh vt v c kh nng gy nhim c cp tnh, mn tnh cho con ngi. Khi xm nhp vo c th cc phenol ni chung v Clophenol ni ring gy ra nhiu tn thng cho cc c quan v h thng khc nhau nhng ch yu l tc ng ln h thn kinh, h thng tim mch v mu. Do vy vic nghin cu, xc nh s c mt ca phenol, clophenol v cc dn xut khc ca n tm cch loi b n l iu quan trng v c bit cn thit. Vic phn tch xc nh mc nhim mi trng do phenol v cc clophenol gy ra c nhiu phng th nghim trn th gii quan tm v nghin cu. C quan bo v mi trng M (US - EPA) v cng ng Chu u c nhng quy nh chung cho quy trnh chun phn tch i tng ny. cc phng php phn tch xc nh phenol v cc clophenol thng thng gm 2 giai on.1.S dng k thut tch chit v lm giu.S dng k thut tch chit v lm giu. Chit lng lng trc tip t nc bng dietylete hoc diclometal. Ct li cun hi nc. K thut sc kh v by cht phn tch li. K thut sc kh tun hon. Chit pha rn vi cc cht hp th, XAD-2, XAD-4, C6 , C8, C18 , ...2.S dng cc phng php nh lng S dng cc phng php nh lng nh: Sc kh lng hiu nng cao vi detector quang (uv) v hunh quang (RF). Sc k kh vi detector ion ho ngn la (FID), Bt gi in t (ECD) v khi ph (MS). Phn tch dng chy (FIA). Trc quang.Cc quy trnh phn tch ny u c th p dng vo iu kin nc ta.Trong khun kh lun vn ny chng ti mun nghin cu xy dng mt quy trnh xc nh cc clophenol trong nc bao gm cc bc sau: Nghin cu s dng k thut chit pha rn tch v lm giu cc clophenol trong nc. S dng k thut tch sc k lng hiu nng cao vi detector (UV-VIS) nh lng chng ng thi p dng phn tch mt s mu thc t ti mt s khu vc thuc a bn H Ni. Tuy nhin, do iu kin hn ch ca phng th nghim nn chng ti ch nghin cu vi 5 clophenol bao gm (dn xut t mono cho n penta): 2. Clophenol; 2.4 Di clophenol; 2.4.6 Tri clophenol; 2.3.4.6 Tetra clophenol; Penta clophenol. Chng ITng quan 1.1 Gii thiu v cc dn xut c clo ca phenol1.1.1Khi nimKhi nim

Cc clophenol gm mt dy cc hp cht ho hc, cht i din u tin l Hidroxybenzen c Runge tm thy nm 1943 khi chng ct phn on nha than . Do mang tnh axit nn hp cht ny cn c gi l axitcacbolic hoc axit phelic. V v sau th hin n vi ancol ngi ta gi n l "phenol" [4 ]

Cc clophenol l hp cht hu c c to thnh bng cch thay th mt hay nhiu nguyn t Hidro trong vng thm ca phn t phenol bng cc nguyn t clo

Cng thc tng qut: C6H5-nClnOH vi n = 1-> 5

vi n = 1-> 5 Cng thc cu to ca cc clophenol nh sau:

Vi X = 1 -> 5 nguyn t clo.Cc phn t clophenol lp thnh dy 19 cht gm cc mono, di ,tri, tetra v mt pentaclophenol.1.1.2 Tnh cht vt l ho hc ca cc clophenol nhit phng , hu ht cc clophenol trng thi rn c cu trc tinh th ngoi tr o-clophenol (2.clophnol). Cc cht ny c mi kh mnh . t tan trong nc, thay i t 2,1.10-2 mol/lt vi o-clophenol cho ti 7.10-9 mol/lt vi 2.3.4.6 tetraclophenol, nhng chng d dng tan trong mt s dung mi hu c nh: metanol, te, diclometan, axetonitril, ...[13]

Cc clophenol trong dung dch nc c tnh axit. Tnh cht ny tng ln khi s lng clo th trong vng benzen tng ln. Do c tnh axit nn trong mi trng kim cc clophenol to thnh cc mui tng ng tan tt hn cc clophenol ban u.Bng 1: Tnh cht vt l ca cc ClophenolTTTn hp chtK hiuKhi lngPhn t Nhit siCo (760 mHg)Nhit nng chy Co (760 mHg)

12-Clophenol2.CP128.56174.99

22.4 Diclophenol2.4 DCP163.00210.045

32.4.6 Triclophenol2.4.6 T3CP197.45246.069.5

42.3.4.6 Tetraclophenol2.3.4.6T4CP 231.891501570

5PentaclophenolPCP266.34309->310190->191

1.1.3.ng dng ca cc clophenol

Ngay t u thp k 30, cc clophenol c tng hp trong cng nghip s dng cho nhiu mc ch khc nhau. Trong cng nghip sn xut thuc bo v thc vt, diclophenol v triclophenol c s dng sn xut cc cht dit c nhm phenolxy nh: 2.4-D; 2.3.5-T. Cc tetraclophenol v triclophenol c dng lm thuc dit khun, dit nm mc v ty u, kh trng, pentaclophenol v cc tetraclophenol c s dng tm tre, g nhm chng mi mt v chng mc, ngoi ra cc clophenol cn c s dng trong cng nghip da, dy, vi, si v lm cht trung gian trong qu trnh sn xut thuc nhum, thuc cha bnh.1.1.4c hi ca clophenol i vi ngi v ng vtc hi ca clophenol i vi ngi v ng vt1.1.4.1.c hi ca clophenol vi ng thc vtc hi ca clophenol vi ng thc vt

Cc clophenol vi s nguyn t clo khc nhau c mc c hi khc nhau i vi cc loi ng thc vt. Nhiu th nghim ch ra rng c hi ca clophenol i vi cc loi sinh vt tng theo mc clo ho vng thm v c tnh ca chng cng thay i r rt theo pH ca mi trng. pH thp, cc clophenol duy tr dng phn t v d dng i qua mng t bo. Khi pH tng c tnh ca cc clophenol gim r rt, nh hng ny c bit quan trng khi s lng cc nguyn t clo c mt trong vng khc nhau.

c tnh ca clophenol thay i ph thuc vo s lng nguyn t clo c mt trong vng thm. Cc clophenol c t nguyn t clo gy ra nhng ri lon, cn cc clophenol c nhiu nguyn t clo s nh hng ti qu trnh pht pht ho trong c th sinh vt. Hnh 1: Biu hin tc ng ca clophenol ni ring v ca phenol ni chung i vi qun th sinh hc-Farquahanrsen v cng s nghin cu nhng nh hng ca phenol ln chut cho thy khi tim 2,6 - DCP v 2, 4, 6 - T3CP lm chut b ri lon nh run ry, mt phn x t nhin, thm ch b ri lon trm trng vi 2,3,6 - T3CP km theo thay i nhit c th. Khi tim T4CP v PCP th dn n tnh trng ngt th hoc cht sau thi gian ngn do thiu oxi. Khi tim pentaclophenol vi hm lng 10 n 20 ppm cho thy 90% cht c c thi ra khi c th chut, cn li ch yu c tch lu trong thn, gan v mu. Thn b tn thng sau khong thi gian t 20 n 40 gi, gan b tn thng sau 3 dn 5 ngy.Nghin cu ch ra rng hu nh cc mono - , di - , triclophenol c c tnh va phi khong 23-400g/kg trng lng. Cc clophenol c t nguyn t clo c c tnh gn ging phenol. Cnvi T4CP v PCP th c tnh mnh hn khong 10-40mg/kg trng lng.1.1.4.2. S c hi ca clophenol i vi ngiCc clophenol c mi rt c trng v c c tnh mnh. Chng c kh nng lm ngng t protein v lm bng nng trn da. Biu hin ca triu chng nhim c c clophenol l: chng mt, nn ma, ri lon tim mch, t lit c ng, hn m, nc tiu tr nn xanh nht hoc c mu tro, nhit c th thay i, c bit T4CP v PCP lm da xanh xm li, co tht mt thi gian ngn trc khi cht.

Hnh2: Biu hin tc ng ca cc clophenol v phenol i vi c th con ngi1.2. Ngun thi cc clophenol vo mi trng1.2.1. Ngun t nhinMt s clophenol c pht hin trong mi trng c ngun gc t cc nha cy, nha than v trong mt s loi sinh vt. Trong nha cy, cc sn phm phenol l kt qu ca qu trnh phn hu cc hp cht thin nhin c cu trc khc nhau bng con ng vi sinh vt. Trong than loi antraxit, hm lng cc phenol c th ln ti 0,001%. Trong mt s loi sinh vt 2, 4 - diclophenol c pht hin trong nm penicilium, 2,6 - iclophenol ng vai tr nh mt phenomon ca mt s loi pht ra. Lng ln cc hp cht clophenol c pht hin trong mi trng c ngun gc t nhin .1.2.2. Ngun nhn toVo thp k 70, sn lng hng nm ca clophenol trn ton th gii c tnh khong 200 nghn tn, v ch yu l 2,4 - diclophenol v 2, 3,4, 6 - tetraclophenol. Cc nc sn xut clophenol ch yu l M, Nht, Anh, Thu in. n cui thp k 70, khi cc nghin cu v c tnh ca clophenol kh y th mt s nc pht trin ra quy nh v vic hn ch s dng loi hp cht ny v do sn lng c gim r rt.Trong cng nghip clophenol c tng hp theo hai con ng:(1) Clo ho trc tip phenol to ra cc clophenol hoc polyclophenol vi s c mt ca xc tc v nhit cao.(2) Thu phn cc clobenzen trong dung mi metanol, etylenglycol hoc mt s dung mi khc.Cc cht c sn xut theo con ng th nht l: 2 - MCP; 4 - MCP; 2,4 - DCP; 2,6 - DCP; 2,4,6 - T3CP; 2,3,4,6 - T4CP; PCP. Qu trnh clo ha khng nh lng thu c mt nhm cc clophenol khc nhau. Theo con ng th hai, ngi ta sn xut c 2,5 - PCP; 3,4 - DCP; 2,4,5 - T3CP; 2,3,4,5 - T4CP v PCP. C hai con ng ny u sinh ra nhng cht gy nhim khc nhau c hi cho sc kho con ngi. nc ta do vic s dng cc loi thuc tr su, dit c mt cch ba bi , khng c kim sot cht ch ca cc c quan chc nng. Mt khc cc clophenol cn c thi ra nhiu nh my x nghip, cha x l ngun nc thi mt cch ng n.Nhng ngun ny gy ra s nhim rt ln cho mi trng nc ca chng ta. 1.3. Mt s phng php chit, tch lm giu clophenol1.3.1. K thut sc kh v by lnh (Purge and trap) [15]Hnh 3: Thit b sc kh v by lnhVi k thut ny, cc cht hu c c chuyn t pha lng ln pha hi do kh sc qua mu di p sut kh quyn. Hi cht hu c c cun theo dng kh mang i ti by hp ph v b gi li ti y. Sau khi qu trnh sc kh v hp ph hon thnh, by c gia nhit nhanh ti khong 180oC, s dng dng kh tr c tc 20-60ml/pht trong thi gian 4 pht y cc cht hu c hp ph trn by vo ct sc k (c th s dng thm by lnh c c mu trc khi a vo ct sc k). Gii hn pht hin ca phng php ph thuc vo hiu sut ca qu trnh tch cht bng k thut sc kh by lnh v nhy ca thit b phn tch sc k.1.3.2. K thut sc kh tun hon (Closed - loop stripping tecnique) [15]K thut sc kh tun hon c gio s Grob gii thiu ln u tin vo nm 1973 xc nh cc cht hu c d bay hi trong nc. V bn cht, phng php ny c nguyn tc ging nh phng php sc kh v by gi cht phn tch li.

Hnh 4: Thit b sc kh tun hon CLSAVi k thut ny, dng kh i qua bm ti bnh mu v c phn tn vo nc di dng bt. Mt phn hi cht hu c c cun theo dng kh ra khi mu di ti by hp th lm bng than hot tnh v b gi li ti y. Dng kh sau khi by than li c tun hon qua bm v sc vo mu nc. Qu trnh ny c lp i li li t 2 n 4 gi.Sau khi qu trnh sc kh tun hon v hp ph hon thnh, by than c ly ra. Cc cht hu c hp ph trn by than c ra gii bng mt lng nh dung mi khong 20l. Dung mi ra gii thng thng l CS2. Ngoi ra, qu trnh gii hp cn c th c thc hin theo phng php nhit. Mu ra gii ra s c cho i qua thit b sc k nh tnh v nh lng. [16]y l mt phng php c hiu qu phn tch cc hp cht d bay hi trong nc, c bit l khi phn tch cc hp cht c hm lng rt nh trong nc v n c kh nng lm giu ln. Nu hiu sut thu hi ca c qu trnh l 10% th h s lm giu s l 25.000 ln i vi cc hp cht km bay hi(h phenol), phng php ny cho hiu sut thu hi thp v kh nng chuyn ln pha hi ca chng l km hn v cng vi n ta phi tng nhit ca qa trnh sc kh v hp ph nn gim kh nng hp ph ca by than. Gii hn pht hin ca phng php ny khong 0,1 - 100ng/l khi xc nh cc hp cht hu c d bay hi, cn vi h phenol nhy pht hin khong l/l1.3.3. Phng php chit lng - lng trc tip t ncTheo quy trnh chun ca c quan bo v Mi trng M (EPA) s 604 v 625, phenol v cc dn xut ca chng trong nc ngm hoc nc thi c lm giu bng phng php chit - lng trc tip vi dung mi diclometan. Sau , cc hp cht c nh tnh v nh lng bng k thut sc k kh vi detector ion ho ngn la(FID) hoc detector khi ph (MS), hoc bng k thut sc k lng hiu sut cao (HPLC) vi detector UV hoc hunh quang. Phng php ny s dng cht ni chun 2,4,6 - triclophnol - 13C6 vi GC v 2,4 - dibromphenol vi HPLC. Cc phenolat u c dn xut ho di tc nhn anhidrit axetic thnh dng phenolaxetat. thu hi ca phng php t 40-89% v gii hn ph hin t 1-10ng/l [14].

Theo ISO - 8165 -1, cc phenol c th c chit trc tip t pha nc (khng qua lc) bng dietylete, c cn, lm giu v lm sch qua ct selicagel. Sau , chng c nh tnh v nh lng bng sc k kh vi detector FID hoc FPD [20].1.3.4. Phng php chng ctPhng php chng ct l phng php nhanh, n gin, tn t dung mi v c th p dng phn tch i vi mu nc thi cng nghip nhiu tp cht.Theo phng php chng ct, mu nc dc iu chnh ti pH = 1,5 thm 25% NaCl, v tin hnh chng ct trc tip, hng phn ngng, tim 1 ml vo my sc k lng hiu sut cao HPLC. Khi nghin cu phng php ny vi 5 clophenol cho thy thu hi t 91,9 - 97,3% lp li cao, v gii hn pht hin t 7-16g/l [12].Phng php chng ct kt hp vi k thut ni chun v dn xut ho cc phenolic c p dng phn tch mu nc thi [9]. Vi phng php ny, mu nc c axit ho ti pH 1, thm cht ni chun l 2,6 - dibromphenol, thm dung mi v dung dch NaCl bo ho, ri em chng ct thu pha hu c giu cht phn tch. Sau chuyn cht phn tch vo pha hu c khc ph hp, tin hnh dn xut ho cc phenolic bng pentafluorobenzylbromua 1% trong axeton, ri lm sch mu bng cch cho qua ct florisil v lm kh bng Na2SO4 khan, ui dung mi, tin hnh phn tch sc k kh vi detector ECD. thu hi ca phng php t 75,94 - 89,69% nng 0,01 - 1 mg/l vi DCP v 0,001 - 0,1 mg/l vi cc clophenol c s clo nhiu hn.1.3.5. Phng php ct li cun hi nc [1]

Ct lng - lng li cun hi nc l mt trong nhng phng php nhn lp v tinh ch cc hp cht hu c t hiu qu cao. Phng php ny s dng tinh ch, lm giu cc cht khng tan v t tan trong nc.Hnh 5: Cu to my ct m vi lng Parnas - Wagnerr s dng ct lng - lng li cun hi nc.1. Bnh cp hi nc 2 lt2. Phu rt nc ct3. Phu rt mu4. Bnh cu ng mu 250ml5. Sinh hn6. Bnh hng cht 7. Phu x8. Kho K19. Kho K2

10. Kho K3

Quy trnh ct lng - lng li cun hi nc c tin hnh nh sau: Ly chnh xc 100ml nc c x l s b vo bnh ng nc 250ml, axit ho bng 2ml axti H2SO4 c tinh khit. a mu vo bnh 4 b chit ct li cun hi nc. Dng dung mi dietylete trng bnh nh mc v vo bnh 4, ri tin hnh chng ct. Phn ct c c ui dung mi bng dng kh N2 cho n khi kh, ri thm chnh xc 100l dung mi dietylete. Tim 1l dung dch ny vo my sc k kh vi detector ECD nh tnh v nh lng chng. thu hi ca phng php ny ln hn 70%, vi lp li cao v nhy khng g/l.1.3.6. Phng php chit pha rn (chit lng - rn)1.3.6.1. Nguyn tc chungTrong phng php chit pha rn, cc cht hp ph rn, c din tch b mt ring ln c s dng chit, tch v lm giu cc hp cht hu c t pha nc. Theo phng php ny, mu nc c iu chnh ti pH thch hp c x l s b ri c di qua ct (ct c nhi cht hp ph rn). Do i lc mnh vi pha tnh nn cc cht hu c b gi li trn ct, v sau dng dung mi hu c thch hp ra gii thu cht phn tch.Cc cht hp ph rn c s dng cho chit pha rn bao gm: cc polyme, polyme ng trng hp styren - divinylbenzen, polyme acrylic, tenax - GC, cc pha lin kt C18, C8, C6 - Silica... v thng c bn trn th trng di dng ht, ct nhi rn, dng phim, dng a hay dng mng. Phng php chit pha rn thng c p dng i vi cc cht kh bay hi, cc cht khng chit c bng phng php chit lng - lng.1.3..2. Phng php s dng nha hp ph polystyren - divinyl - benzenTheo phng php ny, nha c p di dng a, v p dng cho phn tch cc phenol trong nc. Trc khi s dng, a c chun b k lng bng cch ngm trong axeton, trong metanol v cui cng ra bng nc ct c iu chnh pH tng ng vi pH ca mu. Mu nc c iu chnh ti pH 2, ri c lc qua a, sau cht phn tch c ra gii bng metanol. Cng vi k thut dn xut ho, ni chun v lm sch trn florisil, khan ho trn Na2SO4 , chng t chit bng a styren - divinybenzen l phng php nhanh phn tch cc clophenol trong nc ngm v nc b mt. thu hi ca phng php kh cao, t 74,14 - 97,92%. Tuy nhin, trc khi lc qua a, mu cn c lc loi cc ht rn [23].Cheung Julic v cng s cng nghin cu chit pha rn (SPE) s dng cht hp ph polystyren - divinylbenzen tin hnh chit hn hp 8 clophenol trong nc v tin hnh x l nc thi vng Sydney. Kt qu cho thy nha khng ion polystyren - divinylbenzen c kh nng hp ph mnh hn than hot tnh. Sau , cht phn tch c nh lng trn thit b GC - MS. nhy ca phng php c ppb [7].1.3.6.3. Chit pha rn s dng a C18a C18 c s dng lm cht hp ph xy dng quy trnh chun xc nh cc phenol trong nc. Theo quy trnh ny, mu c kim ho v thm cht ni chun 2,4,6 - triclophenol - 13C6, c axetat ho thnh phenolaxetic vi tc nhn anhidritaxetat, c i qua a C8. Cht phn tch b gi trn a c ra gii bng axeton. Dch chit c c cn v c nh tnh, nh lng trn thit b GC-MS. thu hi ca phng php t 60-95%, vi gii hn pht hin 5-20ppb[13].Nghin cu ca S.Dupeyron v cc cng s cho thy pentaclophenol trong nc ung hoc nc thi cng nghip c iu chnh ti pH2,6, bm qua a C18, c ra gii bng hn hp axetonitril + nc + axit axetic, c nh lng bng HPLC vi detector quang (UV) hoc hunh quang (RF). nhy ca phng php 0,1g/l. Nghin cu ch ra rng khi thm NaCl vo mu nc lm tng phn cc ca nc v do s nng cao c thu hi ca pentaclophenol ln t 87-90% [12, 2].Theo Goncharov V.V. v cc cng s, lng ln mu nc c bm qua a C18 lm giu trc mi php phn tch. Cc nh nghin cu s dng k thut sc k kh kt hp vi khi ph (GC-MS) phn tch. Gii hn pht hin ca phng php ny l 1 -10ng/l [5].a C18 cng c Bao M.L. v cc cng s s dng chit v lm giu cc phenol v dn xut ca phenol trong nc. Theo nghin cu ny, mu c axetyl ho trc tip bng anhydritaxetic thnh phenolaxetat, ri c chit bng a C18 v c nh lng bng phng php sc k kh s dng detector khi ph. Phng php ny c chnh xc v nhy cao c dng phn tch cc hp cht ca phenol bao gm: phenol, ankyl phenol, phenol halogen ho, nitrophenol trong nc my, trong t v cc mu nc sng. thu hi ca phng php ln hn 80% v nhy t 2-50ng/l [3].Jitka Frebortava, Vera Tatarkovieova phn tch 7 clopenol trong nc thuc danh mc cc cht gy nhim mi trng lu di do EPA a ra: 2 - clophenol (2 - CP); 4- clo - 3 metylphenol (4,3 - CMP); 2,6 - diclophenol (2,6 - DCP) ; 2,4 - diclophenol (2,4 - DCP); 2,4,5 - triclophenol (2,4,5 - TCP); 2,4,6 - triclophenol (2,4,5,6-TCP); pentaclophenol (PCP). Cc tc gi nghin cu chit pha rn s dng pha lin kt C6, C8, C18 - Silica xem xt s ph thuc ca thu hi vo th tch dung mi ra gii, pH mu v th tch mu tm cht hp ph ti u. Kt qu cho thy C18 - Silica l cht hp ph t hiu qu cao nht trong s cc cht c kho st [21].1.3.6.4. Chit pha rn s dng cht hp ph XAD - 2, XAD - 4Cht hp ph XAD - 2 cn gil nha XAD - 2, c s dng rng ri trong phng php chit lng rn. XAD - 2 c dng ht nh, ng knh 0,25 - 0,5mm mu trng, c dung lng hp ph ln do din tch b mt ln ti 300m2/g. Theo phng php chit ny, mu c x l s b, c iu chnh ti pH 2, ri c di qua ct XAD - 2 tch v lm giu cc clophenol. Sau , cht phn tch c gii hp bng cc dung mi thch hp n khi thu ht, ri em c cn v nh lng trn GC - ECD hoc GC - MS. thu hi ca phng php t 75-87%, v nhy ppb [ 1, 24, 11, 22].Cht hp ph XAD - 4 cn c gi l nha XAD - 4. l nha polystyren c kch thc nh, ng knh trong 50Ao thng c s dng lm cht hp ph cc phenol v dn xut. Nha c dung lng hp ph ln, do din tch b mt ring ln 750m2/g.Zheng - Liang Zhi v cng s tin hnh chit v lm giu cc phenol trn XAD - 4, sau ra gii cht phn tch trn pha rn v p dng phng php o mu s dng thuc th 4 - amino antipyrin xc nh tng lng cc phenol trong nc. Gii hn pht hin ca phng php ny ti 0,2ng/ml v khong tuyn tnh 0,5-60ng/ml [27].Trong nghin cu ca mnh. Elina B. Caramao v cc cng s Brazin s dng XAD - 4 chit cc phenol t mu nc kh ho than sau khi c axtyl ho bng anhidritaxetic. Cht phn tch c ra gii v nh lng trn thit b sc k khi ph GC - MS. Qua nghin cu ny, h pht hin ra 20 hp cht phenol c axetyl ho trong hn hp phc tp ca nc kh ho than [26].Mt nghin cu mi y s dng nha XAD - 4 chit v lm giu cc clophenol trong nc. Theo quy trnh ny, mu nc c kim ho ti pH 13 c lc s b loi cc tp cht th, ri axit ho ti pH 2; tin hnh chit cc clophenol trn nha XAD - 4, sau ra gii bng dietylete. Cc clophenol sau khi ra gii s c gii chit khi pha hu c bng dung dch NaOH 0,2N, ri axit ho ti pH 2 v chit li bng dietylete. Dch chit c lm kh bng Na2SO4 khan, ri c cn bng dng kh nit, thm dung mi n - hecxan v bm 1l vo my sc k kh vi detector ECD nh lng. thu hi ca phng php t 68-83% vi nhy pht hin nh hn 0,01g/ml [22].1.3.6.5. Phng php vi chit pha rn nng cao hiu sut thu hi khi phn tch cc phenol v n gin ho quy trnh phn tch, Buchholz v cng s xut phng php vi chit pha rn (Solid - phase micro extration: SPME). Phng php ny da trn c ch li cun cc hp cht hu c t pha nc hoc pha kh ln si silica c ph cc cht hp ph thch hp nh polyacrylate... Cc hp cht hu c bm trn si silica s c a trc tip vo bung ho hi ca thit b sc k bng mt bm tim ci tin.Theo k thut ny, khi pt tng rt ngc ln, si hp ph s tht vo su trong kim trnh b gy khi rt kim ra khi np y bnh mu hoc khi bm vo bung hng ho hi ca thit b sc k. Si silica di 1cm c ph mt lp polyacrylate dy 95m. Bng k thut ny, cc nh nghin cu th nghim phn tch 11 loi phenol khc nhau vi gii hn di l 0,8g/l i vi phenol v 0,01g/l i vi 4 clo - 3 metyl phenol, tng ng l cc gi tr cao nht v thp nht trong gii hn pht hin ca 11 loi phenol em th nghim. chnh xc ca phng php rt cao, vi sai s ln nht khi xc nh pentacclophenol l 12%, cn cc cht khc ch khong 4-5% [6].1.4. Mt s phng php xc nh cc clophenol trong nc1.4.1 xc nh phenol v dn xut ca n bng phng php trc quang Vi thuc th 4 - aminoantypirin khi c mt kaliferoxianua K3[Fe(CN)6] hoc amonipesunphat (NH4)2S208 trong mi trng pH 10. Sn phm mu c o trc tip bc sng 500mm hoc c chit ln clorofom v o mu bc sng 460mm. Phng php ny c u im l x l mu nhanh, khng phc tp nhng ch cho php phn tch hm lng cc phenol v dn xut c nng 0,001 - 0,005% [18].Ci tin cc phng php ny v s dng cht hp ph XAD - 4 tch v lm giu cc clophenol t dung dch nc ti pH 2 trong h thng dng lin tc. Cht phn tch c ra gii bng cch bm lin tc dng dung dch nc c pH 13 qua nha, ri a trc tip vo dng thuc th 4 - aminoantipyrin. Sn phm ca phn ng c chit bng cloroform v o mu. Php phn tch c nhy kh cao khong 0,2ng/ml vi khong tuyn tnh 0,5-60ng/ml [27]Hn ch ca phng php ny l thuc th 4 - aminoantipyrin km chn lc vi cc phenol Ch xc nh c lng tng cc phenol trong nc.1.4.2. Phng php sc k lng hiu sut cao (HPLC)Phng php sc kh lng hiu sut cao v phng php sc k kh c C quan Bo v Mi trng M v Chu u s dng nh l phng php chun xc nh phenol v cc dn xut ca phenol. Phng php c nhy rt cao, khong ppb.S. Dupeyron v cc cng s tin hnh chit pha rn v s dng phng php sc k lng hiu sut cao xc nh cc phenol trong nc [6]. Theo phng php ny, ct tch c s dng l ct pha o c kch thc (12,5cm x 4,0mm), . Mu sau khi i qua ct tch s c i qua detector quang (UV) hoc hunh quang (RF) vi chng trnh bc sng ca UV l : 270nm clophenol v 2 - CP, 285 nm, 289 nm v 303 nm tng ng cho 2,4 - DCP; 2,4,6 - TCP v PCP, cn bc sng hp th ca hunh quang l 270 nm v pht x l 298 nm. Phng php ny c nhy khong 0,1g/l.Riehn O., Jeken M. s dng phng php sc k lng hiu sut cao vi ct tch l ct pha o xc nh phenol v cc dn xut ca phenol trong nc thi. Phenol v cc dn xut ca phenol u c xc nh bc sng 500nm khi c mt N - metylbenzothiazo-2hydrazon v Ce(NH4)2(SO4)3 trong mi trng axit mnh. Gii hn pht hin ca phng php t 1-20ng trong mt ln bm muMt s nghin cu khc cng s dng phng php sc k lng hiu sut cao xc nh phenol v cc dn xut ca phenol trong nc vi nhy khong g/l [21, 8,].1.4.3. Phng php sc k khPhng php sc k kh ct mao qun kt hp vi detector khi ph v k thut chn lc ion (GC - MS SIM) c nh gi l phng php c nhy cao nht (khong ng/l) trong vic phn tch phenol v cc dn xut ca phenol.Theo ISO - 8165 - 1, c 31 hp cht gm phenol v dn xut ca phenol c xc nh bng phng php sc k khi vi detector ion ha ngn la (FID) v detector bt gi in t (ECD). Gii hn pht hin ca phng php t 0,1g/l - 1 mg/l [18].Cheung Julic v cng s tin hnh chit pha rn tch v lm giu hn hp cc phenol trong nc thi vng Sydney. Cc phenol ny c nh tnh v nh lng bng phng php sc k kh khi ph vi nhy khong ppb [10].Theo nghin cu ca Heberer Thomas v cng s, khi tin hnh chit pha rn tch v lm giu phenol v hn 50 dn xut ca phenol, sau s dng phng php sc k kh khi ph vi k thut chn lc ion nh tnh v nh lng chng cho nhy kh cao khong ng/l. Trong phng php GC - MS - SIM, h s dng hai loi ct mao qun l HP-5 c kch thc (25m x 0,2mm x 0,33) v Rtx - 200 c kch thc (30m x 0,32mm x 0,25m) [17].Chng 2Phng php nghin cu2.2.1. Phng php sc k kh lng hiu sut cao (HPLC) v nhng vn cn nghin cu ng dng2.2.1.1. Nguyn tc chung ca phng php HPLCSc k lng l qu trnh tch mt,hoc hn hp cc cht trong ct tch sc k trng thi lng, m y thc cht l s vn chuyn v phn b li lin tc ca cc cht tan (mu phn tch) qua tng lp ca ct cht nhi (pha tnh) t u n cui ct tch. Trong nhng iu kin sc k nht nh th cht tan lun c phn b gia hai pha ng v pha tnh tun theo nh lut phn b. Mt khc, mi cht c cu trc phn t v tnh cht khc nhau, nn kh nng tng tc ti pha tnh v kh nng ho tan trong cc dung mi ra gii (pha ng) khc nhau, do vy tc vn chuyn cc cht tan qua ct l khc nhau. V th to ra s tch ca cc cht khi qua ct sc k.Trong k thut HPCL, mu phn tch c bm vo ct qua mt van bm mu, sau nh mt bm cao p bm pha ng chy qua ct sc k vi mt tc xc nh thc hin qu trnh tch.Qu trnh tch trong ct sc k l s tng tc ca cc cht phn tch vi pha tnh ng yn trong ct tch v pha ng lun chuyn ng qua ct tch vi tc nht nh. y l qu trnh chnh din ra trong ct tch ca k thut HPLC. S tng tc ca cht tan vi pha tnh c th din ra theo: Tng tc hp ph Tng tc trao i ion Tng tc ry phn tV th cng c ba loi sc k tng ng vi ba bn cht ca kiu tng tc ny. Sc k hp ph (pha thng NP - HPLC, pha ngc RP-HPLC) Sc k trao i ion (EX-HPLC) Sc k ry phn t (Gel-HPLC)Trong HPLC vic pht hin cc cht phn tch nh cc detect v sau c ch th sang b phn ghi nhn kt qu. Tu theo i tng, yu cu, nhy ... v c bit l bn cht ca cht phn tch m chn cc loi detect khc nhau, nh ph hp th phn t hay hunh quang, v.v...Detect ph bin nht l detect hp th quang phn t vng ph UV-VIS. Thc cht ca detect loi ny l cc my ph hp th phn t vng t ngoi (UV) v kh kin (VIS). Bung o cha cuvt c thay bng cc cuvt ng (flowcell) c th tch rt nh t 3-7l. Vic o v pht hin cc cht phn tch hay hp cht ca chng l da trn c s hp th quang phn t ca cht trong dung dch (trong pha ng ra gii) ti mt di sng nht nh. Dung dch y l pha ng (c ho tan cht phn tch) ca qu trnh sc k, dung dch c chy lin tc qua bung o (flowcell). Cc cht phn tch tan trong pha ng c th cho ph hp th trc tip ca chnh n hay o gin tip hp cht ca chng vi mt thuc th thch hp c kh nng hp th quang tt. Cc phn ng to thnh cc hp cht o ny phi c tnh cht nh lng hon ton trong iu kin xc nh. Vi loi detect ny b phn in t thu nhn v khuych i tn hiu l cc nhn quang in kiu ng hay i t pht quang (photodiode). Ni chung y l loi detect c nhy tng i cao, n gin, d dng v khng qu t, nn rt ph cp ca h trang b HPLC. Nguyn tc cu to ca mt h HPLC c m t trong hnh 7(trang 30).Ngoi ra cn c cc detect loi khc nh detect hunh quang, in ho, khi ph, v.v... Nu cht phn tch ph hp vi nhng loi ny th nhy s tt hn detect UV-VIS.2.2.1.2. Sc k lng hp ph pha ngc Trong sc k HPLC hp th c chia thnh hai h: hp ph pha thng (NP-HPLC) v h hp ph pha ngc (RP-HPLC). S khc nhau gia hai h ny ch yu l do pha tnh ca chng c c trng vt l ca b mt khc nhau.H hp ph pha ngc (RP-HPLC), pha tnh (SP) thng l cc silica trung tnh c alkyl ho nhm - OH trn b mt bng cc nhm ankyl ca mch ccbon C2, C8, C18 hay nhn phenyl, v vy n c b mt khng phn cc hay t phn cc v k nc. Pha ng l h dung mi ra gii phn cc, thng l cc dung mi hu c, c th ho tan tt trong nc, hay c thm dung dch m pH c trn vi nhau theo nhng t l nht nh, v d CH3OH/H2O, CH3CN/H2O, v.v ... Trong nhiu trng hp H2O li l mt thnh phn chnh ca pha ng. Chnh nh nhng c tnh nh vy nn h thng RP-HPLC c s dng rt ph bin tch nhiu loi hn hp mu t v c n hu c, t cht phn cc n khng phn cc. Do vy, thnh phn pha ng l mt yu t nh hng r rt n kt qu tch sc k nh thi gian lu, phn gii, chiu cao ca pic sc k. Chnh do tnh cht ny m h RP-HPLC c tnh linh hot cao trong qu trnh sc k i vi nhiu cht mu v c s dng nhiu.Bn cht ca s tch sc k trong ct l da trn tnh cht hp ph ca pha tnh. Trn b mt pha tnh din ra cc qu trnh cn bng ng hc ca s hp ph, l qu trnh hp ph v ra gii lin tc trn ct tch theo s sau:Sr + Xi S(Xi) S(Xi) + M M(Xi) + SrTrong :Sr : pha tnhS(Xi): cc phn t cht tan b hp ph trn b mt pha tnh SrM: cc phn t pha ngXi : s cc phn t cht tanM(Xi) : phn t cht tan trong pha ng MTrong qu trnh sc k, khi chng ta bm pha ng qua ct tch, thc hin sc k, cc cht phn tch b lu gi trong ct tch ( trn pha tnh) bao lu l tu thuc vo s tng tc hp ph ca n vi pha tnh v theo ho tan ca cc cht vo pha ng. Cc cht c ho tan ln ( phn cc ln) s c thi gian lu gi nh. Thi gian lu gi ca cht tan trong h pha ngc c th c tnh gn ng theo cng thc sau. Lnk'i = Vi

Trong : k'i - h s dung tch ca cht tan iVi - th tch phn t ca cht tan i (ml/mol)R - hng s kh (1,9865 Cal/mol.K)T - nhit ca h (Ko) M - phn cc ca pha ngS - phn cc ca pha tnhi - phn cc ca cht tanns , nM - s mol ca pha tnh v pha ng trong ct tchCng thc ny ch cho gi tr gn ng ca k'i. Gi tr k'i ny c tnh trong cc iu kin chun, iu kin l tng. Trong thc t mu phn tch ch dng gi tr k' ny d on, gii thch nh tnh thi gian lu gi ca cc cht phn tch dc ra gii ra trc hay sau.Trong qu trnh sc k c c mt h dung mi ph hp th s pha trn gia hai hay nhiu dung mi n theo cc t l khc nhau sao cho pha ng (MP) c tan nm gia hai dung mi n M1 v M2 theo qui tc.EM1 < EMP < EM2L iu cn thit, c c hiu qu tch cao. y cng chnh l tnh linh ng ca h RP-HPLC. Cc yu t ca h pha ngc nh: bn cht v cc c trng ca pha tnh trong ct tch; bn cht, thnh phn v tc ca pha ng; bn cht, cu trc phn t ca cht tan... l nhng yu t quyt nh cho chn lc ca h pha ngc.V vy, khi phn tch phi nghin cu chn c cc iu kin ph hp th mi thu c kt qu tch cao nht, n bao gm cc yu cu sau: Chn pha tnh ph hp theo cc tnh cht v c trng. Nh loi ht, xp, c ht, kch thc ct cha pha tnh, ... chn pha ng ph hp: dung mi, thnh phn v tc , ... chn loi detect v cc thng s ca n pht hin v o nh lng t kt qu cao v chnh xc.2.2.1.3 Mt s khi nim v phng trnh c bn ca phng php sc k lng hiu nng cao- T liu ca qu trnh sc k T liu ca mt qu trnh sc k l sc . Mi pc trn sc ng vi mt cu t nht nh ca hn hp cn tch. Din tch hay chiu cao ca pic s dng nh lng, cn thi gian lu l yu t nh tnh. Thi gian t khi bm mu cho n khi t cc i ca pic gi l thi gian lu l thi gian lu ton phn TR , n bao gm hai thnh phn. T0 thi gian mt cu t tr i qua ct (nh l m tan....)v TR l thi gian lu hiu chnh. Da vo sc ta c th tnh c s a l thuyt ca ct ng vi tng cu t theo cng thc:

n = Tuy nhin ngi ta c th tnh s a l thuyt da vo rng ca pc sc kn = 4 X = 5,545 x = 16 x

Hnh6: rng ca pc sc k ti cc v tr khc nhauPhng trnh Van-Deemter Qua kho st r rng thy c s ph thuc ca chiu cao ca mt a l thuyt vo cc iu kin lm vic nh : p sut, tc pha ng , iu kin nhi ct.... Quan h ny iu kin nht nh c m t bng phng trnh Van-Deemter :H = A +B/u +C.u H : chiu cao a l thuyt A : i din cho s ph thuc ca chiu cao a l thuyt vo ng knh ht pha tnh B : i din cho s khuych tn ca phn t cht tan trong ct C: i din cho qu trnh khuych tn ca cht tan t pha tnh ra pha ng v ngc li U : tc ca pha ng

Hnh 8 : ng biu din s ph thuc chiu cao a l thuyt vo tc pha ng. T phng trnh Van-Deemter, ngi ta c th tnh ton c tc ti u Uopt v chiu cao tng ng ca a l thuyt: U

Uopt =

Hmin = A +

Trn thc t , ngi ta thng tin hnh tc gp i tc ti u gim thi gian phn tch. S d c th lm c nh vy v dc bn phi ng cong Van-Deemter thng nh hn nhiu so vi pha bn tri.2.2.1.4 Phn tch nh tnh v nh lng bng HPLC Trong mt h pha chn, i lng c trng cho s tch sc k ca cc cht l thi gian lu gi (TR) ca cht. iu c ngha l, trong mt h pha v trong cc iu kin sc k chn nht nh th mi mt cht phn tch trong hn hp mu phn tch s c thi gian lu c nh. Do , c th phn tch nh tnh cc cht trong mu cha bit bng HPLC thng qua thi gian lu tR ca cht . tin hnh phn tch nh lng, ngi ta a vo mi quan h ph thuc ca nng cht phn tch v i lng o trong sc k l chiu cao pc hay din tch pic, do vy c hai biu thc c s dng trong phn tch nh lng. - Theo chiu cao pic sc k: H = a.C - Theo din tch pic : S = a.C Trong C nng cht phn tch trong mu bm vo ct tcha- h s iu kin th ngimH- chiu cao pic sc k ca cht phn tchS din tch pic sc k ca cht phn tch T mt trong hai phng trnh trn, v nh mt b mu chun l chng ta c th nh lng cht phn tch , hoc theo phng php ng chun hoc theo phng php thm.2.2.2. Thit b v ho cht dng nghin cu2.2.2.1. H thng HPLC H thng trang b HPLC c dng c cc b phn c m t nh trong hnh 7. PPHnh 7. S h thng sc k lng hiu sut cao n ginMP: Pha ngP:bm cao p

P:bm cao pSv : van bm muCl: ct tch sc k

Cl: ct tch sc kD: DetectRe: b phn ghi kt qu

Re: b phn ghi kt quW: dng cht thiV

Va : vng muTrong h thng ny: 1. Bm cao p (Sp) ca hng Orilta (Ty c), trong c b phn o cao p km theo.2. Van bm mu (Sv), van Rheodyne 7010 (M)3. Ct sc k (Cl), ct thp kch thc 250 x 4,6mm, B phn pht hin (D): detect UV - VIS hng Linear (USA) Moden 2004. My t ghi (Re): ghi sc tch di dng pic.My BD-40 ca hng Kipp and Zonen (CHLB c).2.2.2.2. Cc thit b ph tr khc Trong phn thc nghim ny, ngoi h thng HPLC nu phn trn, chng ti cn s dng mt s thit b khc nh: H thng ct hi lu, ct quay ca hng Chrompack (Netherlands) Cn phn tch 4 s ca hng Sartourius (CHLB c) My siu m ui kh cho pha ng Medel 750, chrompack (Netherlands) B micropipet t ng : 20, 100, 200, 1000, 5000l l thu tinh ng mu Dng c thu tinh nh: phu lc/ht chn khng, bnh nn, bnh nh mc, ...2.2.2.3. Cc ha cht Dung dch NaOH , H2SO4, HCl , H3PO4 tinh khit dng cho sc k cc nng khc nhau Nc ct: 2ln, Nha hp ph dng cho chit lng rn XAD-4kh nit tinh khit 99,99% dng c ui dung mi Na2SO4 pA khan (Merck) c nung li 400oC trong 1 gi trc khi dng. Metanol tinh khit cho HPCL ca hng Prolabo (Php) v Merck (c).n-hecxan tinh khit.Diclometan loi cho HPCL, hng Merck.Tetrahydrofuran cho HPLC, hng Merck.Axeton cho HPLC, hng Merck.Cc cht chun clophenol2.2.2.4. Phng php x l s liuCc kt qu thu c trong qu trnh thc nghim c x l theo cc quy lut thng k. nh gi sai s, lp v gii hn pht hin ca phng php thng qua cc i lng.X%: Sai s phn trm tng i.S: lch chun.V: H s bin thin. xc nh khong tin cy ca kt qu chng ti nh gi theo chun Student vi tin cy thng k 95%.Cc biu , th c xy dng theo chng trnh MS-EXCEL 7.0 v chng trnh OGIRIN 6.0.Chng III Kt qu nghin cu v bn lun3.1. Chn cc thng s cho my hplc3.1.1.Chn van bm muVan bm mu l mt dng c a mt lng mu chnh xc mu phn tch vo ct sc k thng qua vng mu . Vng mu l mt yu t xc nh c th thay i c thay i c, tu theo lng mu ta cn bm. . Vng mu cng l nguyn nhn gy ra s dong pc. Ni chung s dong pc sc k ngoi cc yu t v iu kin tch trong ct sc k quyt nh cn c cc yu t khc cng thm vo nh van bm mu, detecter h thng ng dn....... Nn rng tng cng ca pic sc k s do cc yu t ny gy nn . Cc yu t ny l nhng yu t khng mong mun . Nu loi tr nhng yu t ny hay chn c iu kin thch hp cho n khng b thay i v c gi tr nh nht , nh vy chng ta mi c hiu sut tch tt , v pc sc k mi phn nh ng qu trnh tch trong ct sc k. Theo tc gi Phm Lun [3] . thnh phn ny khng c chim hn 10% trong tng rng ca pc sc k.Vi mt th tch mu nht nh nh hn th tch v0, th khi mu c bm vo ct tng th chiu cao ca pic sc k cng tng mt cch tuyn tnh. Nu lng mu np vo ct vs ln hn so vi v0 th chiu cao ca pc khng tng tuyn tnh vi lng mu m rng ca pic tng nhanh (dong pc).Trong thc t phn tch HPLC, ngi ta thng bm mt lng mu nh hn v0. c hiu qu tch cao nht h van 6 chiu ngy nay c th bm mu trc tip bng micro-xylanh theo th tch mu mong mun , khi lng mu nh hn kch thc vng mu th van ny cng rt thun tin v ta khng phi pha long mu.Trong phn thc ngim ny, chng ti chn loi van bm mu 6 chiu v vng mu loi 20l, np mu vo ct tch vi th tch mu chnh xc l 20l cho mi ln sc k.3.1.2 . iu kin ghi pic sc k. ghi nhn v theo di kt qu ca s tch sc k , chng ti dng my t ghi ghi li sc tch dng cc pic sc k , v th cn phi chn 2 yu t sau:a. Thang o ca my t ghiNgoi yu t quyt nh l nng cht, th chiu cao ca pic cao hay thp ph thuc vo th ghi ca my t ghi. Nu nng ca cht phn tch nh ,ta phi gim th ghi tng nhy, khi nng ca cht phn tch cao th ta phi tng th ghi. Tuy nhin, nhy cng tng th n nh cng km.Vi i tng nghin cu y nng ca cc clophenol trong nc l tng i thp nn chng ti chon th ghi 20mV l ph hp cho php o HPLC.Bi v th ghi ta c kt qu thc nghim c n nh cao ca ng nn ( hnh 3.1).b. Tc giy rng ca pic sc k ghi bng recorder l ph thuc vo tc giy.Nu tc giy qu nh th cc pic s st vo nhau v ngc li. thu c pic cn i v d quan st ,ph hp vi thi gian o v tit kim giy, chng ti chn:- Tc giy l 2mm/pht i vi ct Hypersil ODS c ht 5m.(kt qu ch ra hnh 3.1).3.1.3. Kho st chn iu kin pht hin cht phn tch. pht hin v xc nh cht phn tch, chng ti chn:Loi detecter UV-VIS (vng t ngoi ). y l loi detec ter c nhy tng i cao v thng dng trong cc phng th ngim. V th trc ht phi chn bng hp ph ph hp vi vng nng cht ngin cu.Vic chn bng hp th l chn nhy cho php o. Bng hp th c ch s cng nh th nhy cng cao.Do nng ca cc clophenol trong nc c nng thp nn chng ti chn bng hp th 0.02Aufs .Cho vic ghi tn hiu hp th ca cht ngin cu .Vi gi tr ny th khong nng c th pht hin v o ca cc clophenol nm trong vng t nano gam(ng) n microgam (g). Tip l vic xc nh bc sng hp th cc i ca cht ngin cu. i vi cc clophenol cc tc gi nh Jitka Frbortov[21] . ch ra cc vng chng c hp th quang tt. V th chng ti kho st cc bc sng t 220--230nm , xem ti vng sng no cht phn tch c hp th v tch ra khi nhau tt nht .iu kin kho st:Ct sc k pha ngc : hypersil - ODS,5m.Dung mi pha ng : metanol/acetolnitril/H2O (49:48: 3 theo v/v) Vng bm mu : 20lTc pha ng : 1,4ml/ phtBng hp th : 0.05AufsVng bm mu : 20lth ghi ca pc sc k : 20mVT c giy : 2mm/phtDung dch kho st : Hn hp cc clophenol 1ppm (t mono cho n penta). Cc kt qu nghin cu c trnh by trong bng 3.1 v hnh 3.2.Bng 3.1 Quan h gia chiu cao pic sc k v cc bc sng hp th( nm)225(nm )220 (nm) 230 (nm)

2. clophenol (mm

57mm38,5mm26mm

2.4 .diclophenol31mm21mm16mm

2. 4.6 triclophenol63mm42mm28,5mm

2.4.4.6tetraclophenol13,5mm17,5mm12,5mm

Penta.clophenol10mm7mm4.5mm

Theo nh lut lamber-beer th hp th quang ca cht phn tch ph thuc vo nng cht phn tch trong iu kin chn , hp th c th hin chiu cao pic ( H) . Nu trong cng mt iu kin chn th bc sng () no c pic cao nht th ti cht phn tch s c hp th tt nht.Ti mi bc sng chng ti kho st 2 ln tm lp liv ly gi tr trung bnh ca chiu cao pic. Nhn vo kt qu bng 3.1 v hnh 3.2, bc sng = 225nm ca detector. Chng ti c 5 pic cn i, c th tch hon ton v xc nh ng thi c 5 cht. Cng ti bc sng pc sc k ca 5 cht c chiu cao cao nht. V th xt trn 2 mt l chiu cao pic v kh nng tch, chng ti chn bc sng ny = 225nm cho cc nghin cu tip theo.hnh 3.1 Quan h gia bc sng v chiu cao pic sc k

Pha ng:metanol/H:metanol/H20/ Acetolnitril (49:48:3 V/V)

Tc pha ng:1.4ml/pht1.4ml/pht

DetectorUV:225nmUV:225nm

Mu hn hp: 1:2clophenol; 3: 2.4Diclophenol;2clophenol; 3: 2.4Diclophenol; 2: 2.4.6Triclophenol; 4: 2.3.4.6Tetraclophenol: 4: 2.3.4.6Tetraclophenol:

5: Pentaclophenol3.2 Kho st pha tnh ca h RP-HPHC3.2.1 Chn ht pha tnh v kch thc ht pha tnh.Pha tnh l mt trong hai yu t quan trng quyt nh hiu qu s tch cu cc cht. Trong vic tch sc k th bn cht ca cht phn tch l yu t quyt nh n vic chn loi pha tnh no v kch thc ca ht cht pha tnh. i tng phn tch ca chng ti l cc hp cht clophenol c khi lng v phn t khng ln lm. Thuc loi hp cht t phn cc. Do tnh cht ca cht phn tch v tnh cht n nh ca h pha ngc nn chng ti chn kiu sc k h pha ngc nghin cu v tm iu kin tch .Trn c s thit b c sn ca phng th nghim VH2 chng ti chn 2 loi ht pha tnh ODS ca 2 hng sn xut khc nhau MERCK (CH Lin bang c) v hng Shandow (USA), c kch thc ht l 5 m v 5 m phc v cho nghin cu ny .Bng 3.2 v hnh 3.2 cho ta thy nh hng ca kch thc ht pha tnh n kt qu tch

Bng 3.2: Kch thc ht nhi pha tnhSTTHng sn xutng knh ht (Trung bnh)Kch thc ct

1Shandow(USA)5 m250 x 4,6 mm

2Merck (CHLB c)5 m250 x 4,6mm

iu kin c chn kho st:

Pha ng:metanol/H:metanol/H20/ Acetolnitril (49:48:3 V/V)

Tc pha ng:1.4ml/pht1.4ml/pht

DetectorUV:225nmUV:225nm Bng hp th : 0.05Aufs

Tc giy: 2mm/phtMu hn hp: 2clophenol; 2.4Diclophenol; 2.4.6Triclophenol; 2.4.6Triclophenol;

2.3.4.6Tetraclophenol:Pentaclophenol(1ppm).Pentaclophenol(1ppm).Hnh 3.2.nh hng ca kch thc ht pha tnh n kt qu tch. Trong sc k hp th pha ngc (RP-HPLC), pha tnh l ht cht nhi c b mt khng phn cc hay t phn cc. l cc ht silica trn c alkyl ho b mt phn cc. Trong HPLC pha tnh phi tho mn iu kin nh: Phi tr v bn vng vi cc iu kin ca mi trng sc k, c kh nng tch chn lc mt hn hp cht trong iu kin sc k nht nh, xp phi n nh khng b bin dng hay thay i trong qu trnh sc k, cn bng ng hc ca s tch phi xy ra nhanh v lp li, c ht phi ng u... th mi c kt qu tt.Qua thc nghim, chng ti thy rng mc phn tch th ng knh 5m l tt nht. Bi v ng knh ny c ht nh v u lm tng phn gii, c ngha l lm gim chiu cao ca 1 a sc k, do vy tng hiu sut tch sc k. Hn na 1 trong nhng yu cu ca pha tnh l xp. xp ca pha tnh nh hng nhiu n kh tch sc k. Pha tnh Hypersil ODS 5m c kch thc trn, c cu trc xp l loi xp ton phn do vy hiu sut tch kh tt. Hn na ht cht ny c s ng u v kch thc v vy s tch sc k s tt hn (hnh 3.2 nhm pic s 1) . Theo tc gi John W. Dolan chng ta c th c tnh c kh nng tch ca hn hp mu phn tch khi chng ta bit c ng knh pha tnh v chiu di ct tch qua cng thc gn ng. N 3000 . L/dpNh vy, vi ct tch L = 250mm, pha tnh Hypersyl ODS:-Loi 5Loi 5m c s a l thuyt N5 16.000 a.-iu ny ph hp v l gii cho kt qu sc k ca chng ti.iu ny ph hp v l gii cho kt qu sc k ca chng ti.Chng ti chn loi ht pha tnh c ng knh 5m cho cc nghin cu tip theo.3.2.2 Kho st kch thc ca ct tch Ct tch l 1 b phn chnh ca qu trnh sc k v din bin ca qua trnh tch ch yu xy ra y. Kt qu ca qu trnh tch tt hay khng ph thuc rt nhiu vo ct tch. Ct tch c nhiu loi kch thc khc nhau, ct thng t 125 - 250mm, ng knh t 2.5 n 5mm. Tu thuc vo mc ch ca qu trnh sc k m chn kch thc no ca ct cho ph hp c kt qu tch tt v tit kim c dung mi ra gii. .Vi mc ch phn tch, v do iu kin ca phng th nghim, chng ti chn loi ct Hypersil ODS 5m vi kch thc 250 x 4.6 mm. Loi ct ny cho 1 kt qu tch kh tt (Hnh 3.3)Nhng iu kin kho st yu t ny:

Pha ng:metanol/H:metanol/H20/ Acetonitril (49:48:3 V/V).

Tc pha ng:1.4ml/pht.1.4ml/pht.

DetectorUV:225nm.UV:225nm.

Tc giy: 2mm/pht.Ct 250 x 4.6mm Hypersil ODS 5m.Mu hn hp: 2clophenol;2.4Diclophenol;2.4.6Triclophenol; 2.3.4.6Tetraclophenol:Pentaclophenol. 2.4Diclophenol;2.4.6Triclophenol;

2.3.4.6Tetraclophenol:Pentaclophenol. Hnh3.3 : Kho st kch thc ct pha tnh3.3 Kho st pha ng ca h RP - HPLC3.4 Kho st h dung mi ra gii (pha ng)Trong sc k hp th pha ngc, pha tnh l cc cht c b mt khng phn cc nn pha ng phi l h dung mi phn cc, cht tan no c phn cc km hn s b lu gi lu hn trong ct, v vy cht no c phn cc km hn s c ra gii ra sau. Ngc li trong 1 dy ng ng vi h pha ngc th thi gian lu s tng theo chiu di ca mch cc bon, ca nhm th v s nhm th. V vy i vi hn hp nghin cu th ln lut t mono cho n penta c tch .Theo cc tc gi Jitka Frbortov. [21], S. Dupeyron[2]. theo tnh cht ca h pha ngc v tnh cht ca cht nghin cu, chng ti chn ba h dung mi sau tin hnh kho st nhm la chn 1 h dung mi ph hp nht, ba h l:1. Metanol:Acetonitril.2. Acetonitril : H3PO4 0.007M .3. Metanol: H2O: Acetonitril . Sau khi kho st tm mt thnh phn thch hp nht(ti thnh phn kh nng tch cc cht l tt nht) cho tng h pha ng trn chng ti nhn thy cc t l 4. Metanol:Acetonitril... (85 :15 v/v) 5. Acetonitril : H3PO4 0.007M (58 :42 v/v)6. Metanol: H2O: Acetonitril (49 :48 :3 v/v)Kh nng tch ca mi h l tt nht.Bng 3.4nh hng ca h dung mi n thi gian lu

Ct Hypersil ODS 5m250 x 4.6 250 x 4.6 m.7 10 11 13SttH pha ng1

2345

1Metanol:Acetoniltril(85:15 v/v) 7(P)8(p) 9.5(p)11(p)13,5(pht)

2CH3OH : H3PO4 0.007 M(57 : 43 v/v)1013152026

3 Metanol : H2O :Acetonitril(49:48:3 v/v) 56911.518,5

1:2clophenol 3: 2.4.6 triclophenol 2 :2.4clophenol 4: 2.3.4.6 tetraclophenol 2.4clophenol 4: 2.3.4.6 tetraclophenol 5 : penta.clophenol Thi gian lu (tR) ca cht phn tch c 1 ngha quan trng trong k thut sc k. N cho ta bit cc cht phn tch c ra gii nh th no trong cc iu kin chn v c dng xc nh tnh cht phn tch.

H s dung tch ki c xc nh bng cng thc.

ki = (tR -tO)/tO

Qua thc nghim ta xc nh c tR. Vi thi gian khng lu gi mu (tO) c th xc nh c bng vic o khong thi gian xut hin pic ca dung mi (pha ng) c chn sc k. Vi h dung mi CH3OH/H2O/CH3CN. (49:48:3v/v) th tO = 1,5 pht H Axetonitril : : H3PO4 0.007M to=4pht H Metanol: Axetonitril (85:15v /v) t0=3.5pht.

Thng qua tR v tO,chng ti xc nh c h s ki ca mi loi h dung mi. Mi quan h gia h dung mi v h s kc biu din hnh 3.5.Hnh 3.4 Mi quan h ca kvi bn cht pha ng hypersil-ODS , c ht 5m

H s k ca mi clophenol trong mi h dung mi khc nhau cng nhiu th s phn gii (s tch) gia chng cng tt. Nhn vo hnh 3.5 chng ta thy h 3. (Metanol :H2O:Axetonitril). cho ta kt qu tch tt nht. gii thch kt qu bng 3.5 chng ti s dng nh ngha phn cc ca Rohscheneider trong ti liu do tc gi Phm Lun vit[3] , cc dung mi c phn cc l: metanol = 5,11, axetonitril = 5,8 H2O = 10,2 nn ta c phn cc ca h 3 l: 7.6 c ngha l h pha ng 3 l CH3OH / H2O / CH3CN c phn cc nm gia phn cc ca ba dung mi, v to ra lc ra gii tch hp v khc nhau i vi 5 clophenol. V l do m h dung mi th 3 (Metanol: H2O: Axetonitril (49:48:3v /v).tch tt hn 2 h dung mi (1) v (2).Mt khc, chng ta bit rng khi thay i thnh phn pha ng dn n lm thay i chn lc ca 1 h pha sc k. Nu chn lc ca pha ng cao s lm cho cc cht tch c ra khi nhau. chn lc ny ph thuc vo 3 yu t chnh l. Bn cht v c trng ca pha tnh. Bn cht ca pha ng v thnh phn ca n. Bn cht v cu trc ca phn t cht mu. Tt c cc yu t ny quyt nh n h s dung tch ki ca cht tan, tc l s lu gi. V th ch khi chn c thnh phn ph hp th n mi c hiu qu tch tt. Hnh 3.5 cho ta thy nh hng ca h dung mi pha ng n kt qu tch CH3OH:CH3CN CH3OH :H3PO4 CH3OH: H2O:CH3CNHnh 3.5 nh hng ca h dung mi pha ng Qua kt qu kho st trn ta thy rng hai h pha ng 1 v 3 u cho mt kt qu tch tt. Nhng vi h 3 cho ta hiu sut tch cao hn , gi thnh r hn, tuy nhin thi gian lu c di hn mt cht so vi h 1. Trong cc th nghim tip theo chng ti chn h pha ng 3 kho st. 3.3.2 Kho st chn tc pha ngTc pha ng cng c nh hng n qu trnh ra gii ca cc cht Phn tch. khi chn tc pha ng ra gii khng thch hp, s nh hng n kh nng phn gii ca cc cht phn tch, s dong pic, thi gian lu ca cht phn tch... chn c tc pha ng ph hp cho qu trnh ra gii cht phn tch, chng ti tin hnh kho st tc pha ng trong cng mt iu kin nh sau:Pha tnh: ct Hypersil ODS 250 x 4.65

5m.Pha ng:CHCH3OH/ H2O/ CH3CN(49:48:3 v/v).(49:48:3 v/v).Detector:UV 225nm.UV 225nm.Mu phn tch hn hp 5 cht chun 1ppm.Kt qu c ch ra trongbng3.6 v hnh 3.6

Bng 3.6 nh hng ca tc pha ng n thi gian lutch Tc pha ng (ml/pht)123(p)45

1.1,356. (pht)7(p)11(p)12,5(p)23,1(p)

21,45(pht)6(p)9(p)11,5(p)18,5(p)

31,454,5(pht)5,4(p)8(p)11(p)18(p)

Hnh. 3.6.ng biu din s ph thuc ca chiu cao h vo tc pha ng.Pha tnh : ct 250 x 4.6mm ,hypersil ODS 5Pha ng: CH30H/H20 /CH3CN (49:48:3v/v)Detector UV : 225nmHn hp mu 5 clophenol 1ppm Qua kt qu bng 3.6 v hnh 3.6 chng ti thy r tc 1.4 ml th hiu qu tch l tt nht (pc sc k t c c chiu cao , s tch v n nh ca ng nn). 3.4. nh gi phng php phn tch 3.4. nh gi phng php phn tch3.4.1. Kho st lp ng chun Trong qu trnh lm thc ngim, cc mu chun (cc clophenol) c th b phn hu nu lu sau khi pha trong pha ng (v trong pha ng c nc). y chng ti ch xt trong khong tuyn tnh. dng ng chun dy chun c pha t chun gc.2 Clophenol900PPm

900PPm2.4 Diclophenol480PPm.480PPm.2.4.6 Triclophenol500PPm.500PPm.2.3.4.6 Tetraclophenol500PPm.500PPm.Pentaclophenol500PPm.500PPm.V c nng c ch ra trong Bng 3.7 .Chng ti kho st ng chun trong vng nng t 0.02PPm- 0.12PPm, v mu thc t u nh hn 0.1PPm. Kt qu c ch ra bng 7. Bng 3.7: S ph thuc chiu cao pic vo nng cht phn tch. Cc clophenol0.02ppm0.04ppm0.08ppm0.12ppm

2. clophenol8.3mm14.1mm26.4mm37.1mm

2.4 diclophenol4.26.812.718

2.4.6 triclophenol7.512.724.535

2.3.4.6 tetraclophenol3.55.611.316

Penta.clophenol1.22.146

3.4.2 Sai s ca phng php. nh gi sai s ca phng php phn tch nghin cu, cc mu phn tch c chn ti ba im u, gia, cui nm trong khong tuyn tnh kho st trn.Chng ti chn 3 mu c nng 0.02,0.06 , 0.12ppm. C cng iu kin ging nh cc mu kho st tuyn tnh . mi mu chng ti lm nm ln tnh sai s ti ba im ny theo cng thc sau: kt qu bng3.8 cho thy rng vng nng u ca ng chun sai s ln nht khong 4%. Thc t i vi phn tch hm lng vi lng sai s ny l cho php. Vng nng ln c sai s l b nht, khong 0.36%.Bng 3.8 Kt qu tnh sai sMu0.020.080.12

H(mm)HtHiX%HtHiX%HtHiX%

188,33,82626,41,537,137,10

28,58,32,426,826,41,53737,10.3

37,88,36,826,526,40,437,337,10,5

48,58,32,426,126,41,136,937,10,5

58,78,34,526,326,40,437,237,10,5

Tb41.0.36

3.4.3 lp li ca phng php Ngoi yu t sai s , mt phng php phn tch c lp li cao v h s bin thin nh. chng ti tin hnh kho st lp li ca ba mu trn (0.02 ; 0,08; 0.12). lp li c xc nh theo cng thc sau:S =

S*100 H s bin thin theo : V= HtbTrong :HHi Chiu cao pic o ln th iHtb Gi tr trung bnh n ln o(n=5)S lch chunV H s bin thinCc kt qu tnh ton c ch ra bng sau:Bng 3.9Nng mu (ppm) lch chun(S)H s bin thin(V%)

0.020.716.7

0.084.33.5

0.120.41.72

Vi i tng phn tch ca chng ti c hm lng c ppm v nh hn na ,nn h s bin ng phng php ny ( V1= 16.7% , ; V2= 3.5 V3= 1.72 ) l chp nhn c.3.4.4 Gii hn pht hin cht phn tch ca phng phpTheo khi nim v gii hn pht hin bng thc ngim c p dng trong k thut HPLC [3 ] : Gii hn pht hin ( nhy pht hin) ca phng php l nng nh nht ca cht phn tch trong dung dch mu bm vo ct tch sc k thu c tn hiu sc k ca n (Chiu cao ca pic t nht phi bng ba ln dao ng tn hiu ng nn).tc phi c :H(cm)_ > 3n(n dao ng ca tn hiu nn)Sau khi kho st khong tuyn tnh, nng im u l 0,02ppm c chiu cao pic trung bnh l 5,1mm,dao ng ng nn (n