钼（VI）－溴邻苯三酚红－阳离子表面活性剂－β环糊精显色反应的研究及其应用

A Study of No(VI)-Bromopytogallol Red-Cationic Surfuctant-β-cyclodeSxtrin and its Applications

溴邻苯三酚红（ＢＰＲ）在阳离子表面活性剂（ＣＴＭＡＢ）的存在下与钼［Ｍｏ（ＶＩ）］生成蓝色的水溶性配合物，反应灵敏，再加入以适当比例组合的β－环糊情（β－ＣＤ）与阳离子表面活性剂，其灵敏度可进一步提高。配合物的λ＿ｍａｘ＝６００ｎｍ；吸光度Ａ在ｐＨ４．１０～４．７０的ＨＡｃ－ＮａＡｃ缓冲体系中趋于恒定；摩尔吸光系数ε＝８．００×１０４￣４ｍｏｌ·ｃｍ￣－１·Ｌ￣－１；ＭＯ的浓度在０～５μｇ／２５ｍｌ范围内符合比尔定律。加适当的掩蔽剂，可提高选择性。应用此法测定钢样中的钼，与标准值相吻合。

Bromopytogallol Red reacts with Mo(VI)in the presence of hexadecyl-trimethy lammonium bro-mide(CTMAB)to form a water-soluble blue chelate. Its absorption maxium(λmax)is at 585nm,themolar abeorption aoefficient(ε)is 3.34 × 10￣4.Adding appropriate proportion of β-cyclodextrin(β-CD) with CTMAB,the,λ_max shifts to 600 nm and ε increases to 8. 00×10￣4mol· cm￣-1·L￣-1.It is co-incident with Beer’s law in the range of 0～5μg Mo/25ml. This method haS been applied to determine Mo in alloy steel, The results are in keeping With thestandard values.