溴酚蓝-氯化十六烷基吡啶光度法测定水中痕量阴离子表面活性剂

Spectrophotometric Determination of Anionic Surfactants in Natural Waters With Bromophenol Blue and Cetylpyridine Chloride

本文研究了溴酚蓝(BPB)与氯化十六烷基吡啶(CPC),阴离子表面活性剂(AS)与CPC形成缔合物的反应.发现在pH=8.0的NH_3·H_2O-NH_4Cl缓冲溶液中,AS能定量置换出CPC-BPB缔合物中的BPB而显色,其最大吸收在590nm处.阴离子表面活性剂十二烷基本磺酸钠(DBSNa)和十二烷基磺酸钠(DSNa)的ε值分别为2.9 ×10_4和3.2×10~4L·mol^(-1)·cm^(-1).在80μg CPC存在下,DBSNa和DSNa浓度分别在0～80μg/25 ml和0～60μg/25ml范围内符合比耳定律.应用此法测定环境水样中的痕量阴离子表面活性剂,结果满意.

A method for the spectrophotometric determination of anionic surfactants with bromophenol blue(BPB) and cetylpyridine chloride(CPC) was developed. In the presence of anionic surfactants Csuch as sodium dodecyl benzene sulphonate (DBSNa) or sodium dodecyl sulphonate (DSNa)3 at pH 8. 0, CPC reacts with BPB to form ion associated complex. Beer's law is obeyed in range of 0 to 80g/25 ml for DBSNa and 0 to 60 g/25 ml for DSNa. The apparent molar absorptivities are 2.9X104,3.2X104L mol-1 cm-1, respectively. The method has been applied to the determination of trace amounts of anionic surfactants in tap water. Tuo river water and Fuxi river water with satisfactory results.