摘要
研究了铅与2-（3，5-二氯-2-吡啶偶氮）-5-二乙氨基酚（3，5-diCl-PADAP）的显色反应，建立了分光光度法测定化妆品中微量铅的新方法。结果表明：在阴离子表面活性剂十二烷基苯磺酸钠（SDBS）存在下，pH8．5的Na2B4O7-HCl缓冲溶液中，Pb^2＋与3，5-diCl-PADAP及SDBS反应，生成1：1：3紫红色配合物，其最大吸收波长为λmax=561nm，表观摩尔吸光系数ε561=7．14×10^4L·mol^-1·cm^-1，Pb^2＋质量浓度在0～1．35μg·mL^-1符合比耳定律，加标回收率为95．3％～106．2％，相对标准偏差小于3％。
Chromogenic reaction of Pb^2＋ with 2 - （3,5 - dichloro - 2 - pyridylazo） - 5 - diethylaminophenol （3,5 - diCl - PADAP） was studied and a spectrophotometric method for determining lead in cosmetics was established. The experimental results showed that with the existence of sodium dodecyl benzene sulfonate （SDBS） and in a buffer solution consists of Na2B4O7 - HCl pH value 8.5, Pb^2＋ can react with 2 - （3,5 - dichloro - 2 - pyridylazo） - 5 - diethylaminophenol（3,5 - diCl - PADAP） to form a stable 1 ： 1 ： 3 complex of purple - red color. The maximum absorption wavelength is 561 urn. The apparent molar absorption coefficient is found to be ε = 7.14 × 10^4 L·mol^-1·cm^-1. As the Pb^2＋ concentration is in the range of 0 1.35μg/mL, it follows the Beer＇s Law. The method can be applied directly to determine trace Pb^2＋ in cosmetics with satisfactory results.
出处
《日用化学工业》
CAS
CSCD
北大核心
2006年第3期193-195,共3页
China Surfactant Detergent & Cosmetics
关键词
化妆品
表面活性剂
分光光度法
测定
cosmetics
surfactant
spectrophotometry
determination
