摘要
200mL水样经硝酸(3+97)溶液0.1mL酸解15min。移取样品溶液5mL,用硝酸(3+97)溶液定容至10 mL,用电感耦合等离子体质谱法(ICP-MS)测定总铬。另取样品溶液5mL,依次加入pH 5的乙酸-乙酸钠缓冲溶液1mL,30g·L^(-1)的二乙基二硫代氨基甲酸钠溶液0.5mL,1-己基-3-甲基咪唑六氟磷酸盐离子液体100μL,于30℃超声处理15min,离心。在下层有机相中加入2mol·L^(-1)硝酸溶液2mL,超声处理15min,离心后,将上层液用硝酸(3+97)溶液定容至10mL,用ICP-MS测定Cr(Ⅵ)。以总铬含量减去Cr(Ⅵ)含量得到Cr(Ⅲ)的含量。Cr(Ⅵ)和总铬的线性范围均为0~80μg·L^(-1),检出限(3s/k)分别为0.061,0.034μg·L^(-1)。Cr(Ⅵ)的加标回收率在96.4%~105%之间,测定值的相对标准偏差(n=6)在2.1%~5.9%之间。
The sample （200mL） was digested with 0.1mL of HNO3 solution （3＋97） for 15 min.An aliquot （5mL） of the sample solution was taken and diluted to 10 mL with HNO3solution（3＋97）,and total chromium was determined in this solution by ICP-MS.Another aliquot of 5mL was taken from the sample solution,and 1mL of pH 5 acetate buffer solution,0.5mL of 30g·L^-1 sodium diethyldithiocarbamate solution and 100μL of 1-hexyl-3-methylimidazolium hexafluorophosphate were added and the mixture was treated ultrasonically for 15 min at 30 ℃.After centrifuging,the lower organic phase was separated,and 2mL of 2mmol·L^-1 HNO3 solution were added.The mixture was treated ultrasonically for 15 min.After centrifuging,the upper aqueous layer was separated and diluted to 10 mL with HNO3 solution （3＋97）.Content of Cr（Ⅵ）was determined in this solution by ICP-MS.Content of Cr（Ⅲ）of the water sample was found by substracting value of Cr（Ⅵ）content from the total chromium.Linearity ranges of Cr（Ⅵ）and total chromium were same within 80μg·L^-1 and values of D.L.（3s/k）were0.061,0.034μg·L^-1 respectively.Recovery rates of Cr（Ⅵ）obtained by standard addition method were in the range of 96.4%-105% and the RSDs（n=6） were in the range of 2.1%-5.9%.
出处
《理化检验（化学分册）》
CSCD
北大核心
2017年第9期1094-1098,共5页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
国家质检总局科技项目(2015IK217)
