微分电位溶出法测定饮用水中砷含量

Determination on Arsenic in Drinking Water by Differential Potentiometric Stripping Analysis

[目的]为砷的检测寻求一种快速、简便的新方法。[方法]研究在铜离子存在条件下,通过玻碳悬汞电极测定饮用水中砷含量,考查了电沉积电位、电沉积时间、平衡电位、平衡时间对测定结果的影响。[结果]铜离子浓度范围为42.8-57.145 ng/ml;随着电沉积电位、平衡电位的增大,底液空白和加标液的峰高及差比值先增大后减小;随着电沉积时间、平衡时间的增加,底液空白和加标液的峰高先增大后趋向平缓,而其差比值先增大后减小;当电沉积电位为-1.1 V、电沉积时间为100 s、平衡电位为-0.7 V、平衡时间为30 s时,测定结果最好。测定砷的线性范围为0-200 ng,回收率为93.2%-105.4%,相对标准偏差为2.35%。[结论]该法操作快速、简便,结果准确、可靠。

[Objective] The aim of the study was to seek a quick,simple and new method for the detection of arsenic.[Method]In copper ions conditions,drinking water arsenic content was determined through glassy carbon mercury membrane electrode.The effect of electron accumulation potential,electron accumulation time,balance potential,balance time on determination results was examined.[Result] The copper ions concentration range was 42.8-7.145 ng/ml;As the electron accumulation potential,balance potential increased,the peak height and the error ratio of the bottom blank and processing liquid standard solution first increased and then decreasesd;As electron accumulation time,balance time increased,the peak height of the bottom blank and processing liquid standard solution first increased and then gentle,and the error ratio first increased and then decreased.Under the electron accumulation potential of-1.1 V,electron accumulation time for the 100s,balance potential of-0.7 V,balance time of 30s,the determination results was best.The peak currents were linear with the concentration in the range from 0 to 200 ng lead,the recovery was 93.2%-105.4%,and the relative standard deviation was 2.35%.[Conclusion]This method was rapid,simple,accurate and reliable.