钼蓝分光光度法测定水中As（Ⅲ）含量

采用钼蓝分光光度法测定水中的As（Ⅲ）含量。以10.8%（质量分数,下同）的抗坏血酸、3%的钼酸铵、0.56%的酒石酸锑钾和13.98%的硫酸按照体积比为2∶2∶1∶5配制的混合溶液为显色剂,在P（Ⅴ）加入量为10.00 μmol/L、显色时间为30 min的条件下,As（Ⅲ）质量浓度与吸光度的线性相关性最好。该方法的As（Ⅲ）质量浓度检测范围为0~4 mg/L,加标回收率为92%~103%,相对标准偏差为3.0%~5.6%。

Determination of Arsenic in Water by Molybdenum Blue Spectrophotometric Method

As（Ⅲ）in water was determined by molybdenum blue spectrophotometric method. Using the mixed solution of 10.8% （w,same hereafter） ascorbic acid,3% ammonium molybdate,0.56% antimony potassium tartrate and 13.98% H₂SO₄ with 2∶2∶1∶5 of volume ratio as the colour developing reagent,the best linear correlation between As （Ⅲ） mass concentration and the absorbance are obtained under the conditions of P（Ⅴ） dosage 10.00 μmol/L and coloration time 30 min. The detection range of As（Ⅲ） mass concentration is 0-4 mg/L. The standard addition recoveries are 92%-103%. The relative standard deviations are 3.0%-5.6%.