铜(Ⅱ)存在下痕量巯基醋酸钠的吸附伏安法研究

DETERMINATION OF TRACE SODIUM SULFHYDRYL ACETATE IN THE PRESENCE OF COPPER(Ⅱ) WITH ADSORPTIVE VOLTAMETRY

作者以悬汞电极研究了铜（Ⅱ）存在下，痕量巯基醋酸钠（SMA）的差分脉冲吸附伏安行为，认为其电极过程为化学反应-吸附富集-电极反应，即CAE过程，并通过电子转移数、反应氢离子数、络合比的测定，提出了可能的电极反应方程式。在选定的Britton－Robinson（pH3．4）溶液中，在过量的Cu（Ⅱ）存在下，巯基醋酸钠吸附还原峰峰形敏锐，其线性范围为1．0×10－9～1．0×10－7mol／L，富集10min，其检测限降低至20×10－10mol／L。用于人发、指甲试样的测定，结果令人满意。

The adsorptive voltametric behavior of trace sodium sulfhydryl acetate in the presence ofcopper (Ⅱ) was studied with HMDE. It was thought that the electrode process was chemicalreaction-adsorpted preconcentrated-electrode reaction, i. e. CAE, and the reaction formula wasput forward by determination of the transfered electrons,reactive hydrion and complex ratio. InBritton-Robinson buffer solution(pH=3. 4),a sensitive reduction peak of sodium sulfhydryl acetate was observed, with a good linear relationship between the peak and the concentration in therange of 1.0×10-9~1.0×10-7 mol/L. When it was preconcentrated for 10 min, the detectionlimit was 2.0×10-10mol/L. This method was satis factory for the determination of trace sodiumsulfhydryl acetate in human hair and nail.