摘要
研究了采用双硫腙目视比色法快速测定白菜中的微量铅。样品消解后,利用控制溶液酸度的办法加入掩蔽剂以消除共存离子的干扰。再加入双硫腙的三氯甲烷溶液,根据Pb2+离子与双硫腙生成的配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。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,操作简单、快速、准确、省时,测定结果的相对偏差(Dr)<5%,其相对标准偏差(RSD≤2.5%,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。
The study deals with the rapid determination of trace lead in the Chinese cabbage by the visual colorimetry of dithizone. After dissolving the sample, the masking agent is added by means of solution acidity control so as to eliminate the glitch of the coexisted ions. 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 Pb^2＋ 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 colorimetry. This 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 〈 5% ,RSDG is ≤2.5%, which meets the requirement of the national standard. This is a fast, ingenuity and high efficiency method to determine the trace lead.
出处
《西北农业学报》
CAS
CSCD
北大核心
2006年第3期109-111,127,共4页
Acta Agriculturae Boreali-occidentalis Sinica
关键词
双硫腙
目视比色法
白菜
微量铅
快速测定
Dithizone
Visual colorimetry
Chinese cabbage
Trace lead
Rapid determination
