【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。更多还原

【Abstract】 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.更多还原