铜(Ⅱ)存在下的催化极谱波检测福美双

Determination of Thiram Using Polarographic Catalytic Wave in Presence of Cu(Ⅱ)

报道了在酒石酸-酒石酸钾钠-K2S2O8体系中福美双与Cu^2＋的极谱催化波。在0.1mol/L酒石酸-酒石酸钾钠（pH=5.5）缓冲液＋3.0×10^-3mol/LK2S2O8＋4.0×10^-6mol/LCu^2＋底液中,极谱催化波峰电位Ep=-0.8V（vs.SCE）;福美双的二阶导数峰峰电流Ip″与其浓度在1.0×10^-8~1.0×10^-6mol/L范围内呈良好的线性关系（r=0.9994）,检出限为2.0×10^-9mol/L。相对标准偏差（RSD）为1.17%（n=10）。在福美双浓度为1.0×10^-6mol/L时,福美双还原波峰电流为12nA,而相应的福美双在Cu2＋存在下的催化还原峰电流为1.5μA,即灵敏度提高了125倍。样品的检测回收率为83.8%~91.4%。该方法灵敏、简单、快速。

The polarographic catalytic wave of the thiram and Cu^2＋ in tartaric acid, potassium sodium and persulfate systerm was used for the determination of tniram. In 0.1 mol/L C4H606-C4H406KNa 5.5） ＋ 3.0 × 10^-3 mol/L K2S208 ＋ 4.0 × 10^-6 mol/L Cu^2＋ base solution, the peak potential of the tartrate （ pH = polaro-graphic catalytic wave was set at -0.8 V （vs. SCE）, and the second derivative peak current of the catalytic wave was linearly proportional to the thiram concentration in the range of 1.0 × 10 ^-8 - 1.0 × 10^ -6 mol/L （ r = 0. 9994）. The detection limit was 2.0 × 10^-9 mol/L. The relative standard deviations was 1.2% （n = 10）. The reductive peak current of thriam was 12 nA, and the corresponding catalytic current was 1.5 × 10^3 nA. Thus the sensitivity of the catalytic wave of thiram was 125 times higher than that of the corresponding reduction wave. The recovery was between 83.8% and 91.4%. The method is sensitive, simple and rapid.