十四烷基苄基氯化铵共振散射光谱法测定亚氯酸根

Resonance Scattering Spectrometric Determination of Trace Chlorite Using Cationic Surfactants

在乙酸钠-盐酸缓冲溶液中，亚氯酸根能氧化I^-为I2，过量的I^-与I2形成I3^-，阳离子表面活性剂（CS）十四烷基二苄基氯化铵（TDMBA）、溴代十四烷基吡啶（TPB）、十六烷基三甲基溴化铵（CTMAB）、四丁基碘化铵（TBAI）等分别能与I3^-形成缔合物微粒，且均在467nm处产生共振散射效应。ClO2^-浓度分别在0．00948～0．664μg／mL、0．0170～1．706μg／mL、0．0474～0．855μg／mL和0．0237～1．138μg／mL范围内与TDMBA、TPB、CTMAB及TBAI缔合微粒体系的共振强度成线性关系。据此建立了测定ClO2^-的分析方法。各体系的检出限分别为0．00610μg／mL、0．00819μg／mL、0．0378μg／mL和0．00949μg／mL。其中TDMBA体系最稳定，且灵敏度也较高，用于水中ClO2^-的测定，结果满意。

In acidic sodium acetate-HCl buffer solution containing KI, chlorite may oxidize I^- to form I2, and then I2 reacts with excess I^- to give I3^-, which combines with cationic surfactans including tetradecyldimethyl benzylammonium chloride （ TDMBA ）, tetradecylpyridinium bromide （ TPB ）, cetyltrimethylammonium bromide （CTMAB） and tetrabutylammonium iodide （TBAI）, respectively, to form association particles, which produce resonance scattering（RS） effect at 467 nm. The RS intensity at 467 nm of the TDMBA, TPB, CTMAB and TBAI association particle systems is linear to chlorite concentration over the range of 0.00948～0. 664 μg/mL, 0. 0170～1. 706 μg/mL, 0. 0474～0. 855μg/mL and 0.0237～ 1. 138μg/mL ClO2^-, respectively with detection limits of 0. 00610 μg/mL, 0. 00819 μg/ mL, 0.0378 μg/mL and 0. 00949 μg/mL ClO2^-, respectively. Based on this investigation, a new, simple and sensitive analysis method for the determination of chlorite in water has been developed. In the four systems, the TDMBA system possess good stability and high sensitivity. The proposed method has been applied to the analysis of chlorite in water with satisfactory results.