流动注射光度法测定水样中的苯胺

建立了一种利用流动注射光度法直接测定水样中微量苯胺的新方法。该方法是基于苯胺与亚硝酸盐在强酸介质中发生重氮化反应，重氮化反应产物在碱性条件下与甲萘酚发生偶联显色反应，并于495 nm处进行定量检测。对进样环体积、反应圈长度、流速、H₂SO₄和NaNO₂的浓度, NaOH和甲萘酚的浓度，干扰离子等因素进行了考察和研究，优化了分析条件。该方法工作曲线线性范围为0.005～2.0 mg·L-1,检出限(3σ)为0.001 mg·L-1,相对标准偏差(RSD)为0.7%(苯胺0.25 mg·L-1,n=11)。该方法简单、准确、灵敏、快速，用于皮革废水中苯胺的测定，回收率在98.0%到103.0%之间，获得了满意结果。

Determination of Aniline in Water by Flow Injection Spectrophotometry

A new flow injection analysis spectrophotometric method for the determination of aniline in water sample was introduced. It is based on the chromogenic-reaction of diazotization-coupling with 1-naphthol in basic media, and coupled with the flow injection analysis for the determination of aniline. The absorbance intensity was registered in this reaction solution at 495 nm. The volume of the sample loop, the length of the reacting coil and chromogenic coil, the flow rate of reagent, the reagent concentrations of H2 SO4, NaNO2, NaOH and 1-naphthol, and the effect of coexistence ions were studied. The calibration graph is linear in the range of 0.005-2.0 mg x L(-1). The detection limit is 0.001 mg x L(-1), and the RSD was 0.7% (c = 0.25 mg x L(-1), n = 11). The proposed method is simple, accurate, sensitive and rapid, and was successfully applied to the determination of aniline in tannery wastewater with the recoveries in the range of 98.0%-103.0%.