摘要
本文研究了对硝基偶氮间苯二酚（ＰＮＰＡＲ）与溴化十六烷基三甲铵（ＣＴＭＡＢ）形成的离子缔合物ＰＮＰＡＲ－ＣＴＭＡＢ作显色剂与阴离子表面活性剂（ＡＳ）的显色反应。发现在ｐＨ１３．０的ＮａＯＨ介质中，ＡＳ能定量置换出ＰＮＰＡＲ－ＣＴＭＡＢ中的ＰＮＰＡＲ，而使其最大吸收波长６３０ｎｍ处吸光度下降。阴离子表面活性剂十二烷基苯磺酸钠（ＳＤＢＳ）和十二烷基磺酸钠（ＳＤＳ）的ε值分别为３．５×１０￣４，５．８×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），浓度分别在０～８７μｇ／２５ｍＬ，０～６８μｇ／２５ｍＬ范围内符合比尔定律。此法应用于环境水中痕量阴离子表面活性剂测定，结果满意。
A method for the spectrophotometricdetermination of anionic surfactants withPNPAR[(p-nitrophenylazo)-resorcinol] andCTMAB(Cetyltrimethylammoniumbromide)was developed. CTMAB reactswith PNPAR to formanion associate com-plex at pH 13.0,and then,PNPAR in the ionassociate complex is replaced quantitatiVelyby anionic surfactants suchas sodium dode-cyl benzene sulphonate(SDBS) or sodiumdodecyl sulphonate(SDS),which results in adecrease of absorbance at 630nm. Beer;s lawis obeyed in the range of 0 to 87μg/25mL forSDBS and 0 to 68μg/25mL for SDS. The ap-parent molar absorptivities are 3.5×10￣4 and5.8 ×10￣4 L. mol￣(-1).cm￣(-1), respectively,Themethod has been applied to the determina-tion of trace amounls of anionic surfactantshnatural water withsatisfactorv results.
出处
《分析试验室》
CAS
CSCD
北大核心
1996年第2期67-69,共3页
Chinese Journal of Analysis Laboratory
关键词
光度法
表面活性剂
PNPAR
CTMAB
光度法
水
p-Nitrophenyl-azo)-resor-cinol
cetyltrimethylammonium bromide
an-ionic surfactant
spectrophotometry
