流动注射分光光度法测定水中的氯离子

DETEMINATOIN OF CHLORIDES IN WATER BY FLOW INJECTION WITH SPECTROPHOTOMETRIC DETECTION

本文采用流动注射分析（ＦＩＡ）技术．载流中含有Ｈｇ（ＳＣＨ）２和Ｆｅ２＋，注入试样中的氯离子与Ｈｇ（ＳＣＨ），反应，释放出ＳＣＨ－，后者与Ｆｅ２＋形成红色Ｆｅ（ＳＣＨ）给离子，其强度用分光光度法在４８０ｎｍ处测定．记录的吸收峰高度与试样中氯离子浓度成正比．线性范围６．０—１８μｍ／ｍＬＣｌ，检出限达０．１２μｇ／ｍＬＣｌ－．对６．０μｇ／ｍＬＣｌ－连续测定１１次，其ＲＳＤ为３．９％．出样频率为９０样／小时．方法已用于水样中氯离子的测定．

A FIA method for the routine determination of chlorides in water is used in the paper. The carrier stream contains Hg(SCN)2 and Fe(Ⅲ). The chloride of the injected sample reacts with Hg(SCN)2 and liberats SCN-,which in turn acts with Fe (Ⅲ ) turned into the red-colored complex ion Fe (SCN), the intensity of which is measured by spectrophotometry is 480um. The height of the recorded absorhance peak is then proportional to the concentration of chlorde in the sample. The determinable range and detection limit are 6. 0 to 18. 0mg/ml and 0. 12mg/ml respectively. The relative standard deviation is 3. 9%. The method has been applied to determine chlorides in water samples.