三氯甲烷萃取双硫腙目视比色法快速测定水中铅

研究了采用三氯甲烷萃取的双硫腙目视比色法快速测定水中微量铅。样品消解并消除干扰离子后，加入双硫腙的三氯甲烷溶液，根据铅与双硫腙生成的络合物在有机溶剂中的颜色深浅与铅含量在一定范围内成正比的关系，用目视比色法即可快速判断出样品中的铅含量。结果表明，改进后的方法，既保留了原双硫腙光度法消除干扰离子的优点，又不使用任何光学仪器，也不需要配制标准系列色阶，其操作简单、快速、准确、省时，测定结果的相对偏差所〈5．0％，相对标准偏差RSD〈4．0％，可满足国家标准的限量要求。是一种快捷、灵敏、高效的测定微量铅的方法。

Rapid Determination of Lead in the Water by the Chloroform Extraction and Visual Colorimetric of Dithizone

The study deals with the rapid determination of lead in the water by the chloroform extraction and visual colorimetric of dithizone. After the sample is dissolved and the disturbance eliminated, then dithizone and chloroform solution are added in the sample. According to the direct ratio relationship in a certain range between the color degree of the organic solvent with Pb2+ and dithizone in the complex compound and the amount of the lead, the amount of the lead can be rapidly determined by way of the visual colorimetric. The results show that the improved method keeps the merits of dithizone photometric way to eliminate the glitch of the ions, and also, there is no optics instrument and standard color gradation in use. This approach is simple, fast, accurate and time-saving. The relative deviation of determination result is Dr<5%, RSD<4.0%, which meets the requirement of the national standard. This is a fast, ingenuity and high efficiency method to determine the trace lead.