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汞鹽的含量测定,文献介紹多为碘量法。此法操作麻烦,用試药也较多。本文根据药学杂志上所介紹的EDTA直接滴定,經过数次試驗得到了滿意的结果,介紹如下: 昇汞:精密称取检品约0.2克于250 ml的錐形瓶中,加水10 ml使之溶解,加入新鮮配制的Mg-EDTA液25 ml,氨-氯化铵缓冲液10 ml,搖匀,放置1—2分钟,加铬黑T指示剂8滴,用、M/20 EDTA滴定至純藍色。1ml M/20 EDTA相当于2.7152 MgHgCl_2。甘汞:精密称取检品約0.2无,于150 ml的锥形瓶中,加王水及水各5ml,緩緩加热10—15分钟,至有棕色NO_2逸出,放冷,用氨試液中和至有白色沉淀(Hg
Mercury salt content determination, the literature describes mostly iodometric method. This method is troublesome and uses more reagents. In this paper, according to the direct titration of EDTA introduced in the pharmaceutical journal, satisfactory results have been obtained after several tests. The following are introduced: Mercury ascitation: Weigh approximately 0.2 g of the test product in a 250 ml Erlenmeyer flask and add 10 ml of water to it. Dissolve, add freshly prepared Mg-EDTA solution 25 ml, ammonia-ammonium chloride buffer 10 ml, shake, place for 1-2 minutes, add 8 drops of chromium black T indicator, titrate to pure blue with M/20 EDTA. color. 1 ml M/20 EDTA is equivalent to 2.7152 MgHgCl 2 . Calomel: Accurately weigh about 0.2% of the test product. In a 150 ml Erlenmeyer flask, add 5 ml of aqua regia and water and slowly heat for 10-15 minutes until brown NO 2 escapes. Let cool, use ammonia test solution. Neutralization to white precipitation (Hg