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Goggles or safety glasses
1. 實驗室可吃東西?2. 塑膠手套或橡膠手套安全? 防濃酸,有機物可穿透? Limitation of gloves: In 1997, poppular
Dartmouth College chemistry professor Karen Wetterhahn, age 48, died from a drop of dimethylmercury(C2H6Hg, Enviroment contaminant found in fish and birds. Colorless, volatile, toxic liquid; easily inflammable. Easily sol in ether, alc. Insol in H2O.)absorbed through the latex rubber gloves she was wearing. Many organic compounds readily penetrate rubber.
3. 碰到化學藥品? 沖水、洗眼、緊急沖身、 藥品注意事項4. 桌面是否要乾淨?下一位會受污 染?5. 有機物及強酸產生有毒的氣體, 在 hood 使用?若不行?有味道如 何處置?6. 廢棄物的處置?
如何使用電子天平?
1. 與眼同高2. 實驗時將滴定前管內液體的量減去滴定後管內液體的存量即為滴定溶液的用量。3. 完全晾乾 ,未乾?以待填充的滴定液涮洗兩次,避免附著在管壁的液體污染滴定 4. 活栓開關的通道內也可能會有空氣存在,此時應快速地扭轉活栓數次,則氣泡即可排出 5. 滴定速度< 20 mL/min
6. 裝入液體後管中不可有氣泡 .. 彈一彈7. 滴定管的清洗?能用刷子?浸泡清潔液?Peroxydisulfate sulfuric acid8. 可使用 NaOH 浸?9. 機械式或電子式滴定管?
9. 機械式或電子式滴定管?
玻璃製 塑膠製 鐵氟龍製 避免某些可能會被玻璃吸收者測 F *測鋁 *
最後一滴的問題?
Transfer pipet: The transfer pipet is calibrated to deliver one fixed volume. The last drop of liquid does not drain out of the pipet; it should not be blown out.
Measuring pipet: The measuring pipet is calibrated to deliver a variable volume, which is the difference between the volumes indicated before and after delivery.
若是定量者如 1mL, 5mL 等 transfer pipet使用。若需 5.6mL ,則以開始 1mL 至終點為 6.6mL 使用 measuring pipet
The Ostwald-Folin pipet is similar to the transfer pipet, except that the last drop should be blown out.
Serological pipets are measuring pipets calibrated all the way to the tip; the last drop should be blown out.
The transfer pipet is more accurance than a measure pipet.
常見為 a 及 b
如何使用安全吸球?使用刻度吸管取物時,切勿用嘴吸取,請用自動吸管唧筒或安全吸球。請參考
http://general.chemistry.pu.edu.tw/lab/3waybulb.htm
空氣閥
吸取閥
排空閥
Micropipets
以微量吸管 Pipetman P 的使用作為例子
A, 保持微量吸管垂直,將按鈕壓至第一段; B, 微量吸管頭尖端浸入溶液 (3-5mm),緩慢釋放按鈕; C, 保持微量吸管垂直,將微量吸管頭與容器壁接觸,慢慢壓下按鈕至第一段; D, 壓至第二段把溶液完全釋放出; E, 釋放按鈕回原狀。
注射器 ( 毛細管 )
1.HPLC
2. 薄層分析
過濾
真空幫浦或水龍頭
緩衝作用 ( 或被真空油回衝 )
濾紙放於磁漏斗上,濾液向下,殘渣收集
用灰化方式?
如何摺濾液
先加水濕潤?直接倒,速度快?濺出?
乾燥:高溫,再放入discator 中降溫,避免潮濕
Desicator 中常用的乾燥劑:Mg(Clo4)2, BaO, Al2O3, P4O10, CaCl2, CaSO4, SiO2
凡士林