摘要
研究了二溴对甲基偶氮甲磺（ＤＢＭ－ＭＳＡ）与铅的显色反应，在０．２４ｍｏｌ／ＬＨ３ＰＯ４介质中，铅与ＤＢＭ－ＭＳＡ发生灵敏的显色反应，生成稳定的蓝色配合物。其组成比为Ｐｂ（Ⅱ）ＤＢＭ－ＭＳＡ＝１２，最大吸收波长在６４２ｎｍ，表观ｍｏｌ吸光系数达９．５４×１０４，铅的浓度在０μｇ／２５ｍＬ～１５μｇ／２５ｍＬ服从比耳定律，可以允许大量的金属离子（除钙外）共存。进一步研究发现，结合ＫＩ－ＭＩＢＫ萃取法，可彻底消除钙对测定铅的影响，用于各种化妆品中铅的分析，结果令人满意。
A new reagent dibromo p methyl methylsulfonazo(DBM MSA)was studied as a sensitive and high selective chromogenic reagent for lead in this paper.ln thixs 0.24mol/L H 3PO 4medium,DBM MSA reacts Pb(Ⅱ)to form a stable 1∶2 blue chelate.The maximum absorption of this chelate lies at 642nm with an apparent molar absorptivety of 9.54×10 4.Beer's law is obeyed in the range of 0μgPb 2+ /25mL～15μgPb 2+ /25mL.,Relatively large amounts of coexisting elements including noble metals can be bome.The proposed method has been applied to the determination of lead in cosmetics with satisfactory results.
出处
《日用化学工业》
CAS
CSCD
北大核心
1998年第6期48-49,共2页
China Surfactant Detergent & Cosmetics
