水中痕量银的浊点萃取-火焰原子吸收光谱测定法  

Determination of Trace Silver in Water Samples by Flame Atomic Absorption Spectrometry after Cloud Point Extraction

作　　者：张旻杰[1] 滕莉丽[1] 饶美香[1] 

机构地区：[1]赣南师范学院化学与生命科学学院,江西赣州341000

出　　处：《环境与健康杂志》2009年第3期250-252,共3页Journal of Environment and Health

基　　金：江西省自然科学基金资助项目(2007GZH0377)

摘　　要：目的建立浊点萃取-火焰原子吸收光谱测定水中痕量银的方法。方法以二乙基二硫代磷酸(DDTP)为络合剂,以非离子型表面活性剂聚乙二醇辛基苯基醚(TritonX-114)为萃取剂,富集、分离水中痕量银,采用火焰原子吸收光谱法进行检测。研究了溶液的酸度、络合剂、表面活性剂和甲醇浓度、平衡温度和时间、干扰离子对浊点萃取效果的影响。结果在优化的实验条件(0.1mol/L的DDTP溶液0.5ml、50g/L的TritonX-114溶液0.5ml、1mol/L盐酸5ml、40℃加热15min)下,银在0～100ng/ml浓度范围内线性关系良好,其线性回归方程为A=0.0058cAg+0.0016,r=0.999,检出限为0.83ng/ml,平均回收率为97.0%～105.0%,RSD为3.1%。5000倍的K+、Na+、Ca2+、Mg2+、NO3、SO4、Cl-,1000倍的Al3+、Zn2+,500倍-2-的Fe2+、Mn2+,100倍的Pb2+、Cu2+对银的测定没有干扰。结论该方法具有简单、准确、高效、高选择性、高灵敏度的特点,适用于环境水样中痕量银的测定。Objective To develop a new method for the determination of trace silver in water by flame atomic absorption （FAAS） after cloud point extraction. Methods Diethyldithiophosphate （DDTP） and triton X-114 were respectively used as the chelating agent and surfactant. The effects of experimental conditions such as acidity, concentration of chelating agent, surfactant and methanol, equilibration temperature and time, interference ion on cloud point extraction were investigated. Results Under the optimum condition, 0.5 ml of 0.1 mol/L DDTP solution, 0.5 ml of 50 g/L Triton X-114 and 5 ml of 1 mol/L hydrochloric acid were added and the volume was made up to 50 ml. The mixture was heated in a thermostatic bath at 40 ℃ for 15 min,the linear range of determination for silver was 0-100 ng/ml, the equation of linear regression was A = 0.005 8c Ag＋ 0.001 6, r = 0.999. The detection limit was 0.83 ng/ml, the recovery rate was in the range of 97%-105% ,and the relative standard deviation was 3.1% （n=11 ） for 20 ng/ml Ag. There was no significant interference for silver solution containing 5 000 times of K^＋, Na^＋, Ca^2＋, Mg^2＋, NO3^-, SO4^2- and Cl^-, 1 000 times of Al^3＋ and Zn^2＋,500 times of Fe^2＋ and Mn^2＋, 100 times of Pb^2＋ and Cu^2＋. Conclusion The method is rapid, accurate, simple and applicable to the determination of trace silver in water samples.

关 键 词：水 浊点萃取 火焰原子吸收光谱法 银 

分 类 号：O657.3[理学—分析化学]