PbXO配合物主次波长分光光度法测定环境水中铅

铅和二甲酚橙在醋酸-醋酸盐体系(pH=5.8)中发生反应,当掩蔽剂硫脲和柠檬酸铵存在时,反应具有较高的灵敏度和选择性。在该反应基础上,应用主次波长分光光度法替代普通分光光度法测定铅。结果表明,该法具有良好的精密度和准确度,计算曲线稳定,相对标准偏差<1.67%,回收率98.79%~107.6%。logy-logC在0.022~2.5μg/L之间具有良好的线性关系,且检出限低至0.007μg/L。该法适于基层应用和推广。

Determination of Pb in environmental water based on PbXO complex by primary-secondary wavelength spectrophotometry

The reaction between Pb2+ and xylenol orange(XO) was studied at pH 5.8 in HAc-NaAc buffer.It was sensitive and selective with the presence of sulfocarbamide and ammonium citrate.The new method named as primary-secondary wavelength spectrophotometry(PSWS) was applied instead of single-wavelength method for the determination of Pb based on the above-mentioned reaction.Results showed that such a method resulted in a good precision and high accuracy,the calculated curve was very stable.By analyzing several samples,the RSDs were less than 1.67% and the recovery rate of Pb was between 98.79%～107.6%.Within the range of 0.022～2.5 μg/L,the parameter log y was linear with log C and the DL was lower to 0.007 μg/mL.The method was suitable to be used and spreaded in departments of basement layer.