Abstract A simple and rapid method has been reported for the determination of iodate in food grade salt samples where iodate has been used for the oxidation of phenylhydrazine to phenyldiazonium ion which then couples with 2-naphthol or with 8-hydroxyquinoline to produce orange red azo dye. The dye was extracted with microliter volume of 2-propanol, when the phase separation occurred by addition of ammonium sulphate, a process called salting out homogeneous liquid liquid microextraction (SH-LLME), and analysed spectrophotometrically. Relative efficiencies of both the coupling reagents were compared for iodate determination, when both coupling agents, 8-hydroxyquinoline and 2-naphthol, produced relatively comparable results. The method has been optimized for the reaction time, and type of extracting solvent and salt for phase separation. A linear calibration curve was obtained for 0.08−10 mg L−1 of iodate with correlation coefficient of 0.998 and limit of detection of 16 μg L−1. Food grade salt samples have been analyzed with adequate recovery in spiking experiments, being, 86.2–114.6 (RSD, 6.6–12.6 %) and 90.8–111.3 (RSD, 7.1–12.6 %) using 2-naphthol and 8-hydroxyquinoline as a coupler, respectively. The SH-LLME avoids pH adjustment of the final test sample before extraction, and Cu(II) and Fe(III) up to 1 and 6 mg L−1, respectively, can be tolerated. Enrichment factors with the two reagents in that order were 21 and 20, respectively.

中文翻译：

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盐析均相液-液微萃取分光光度法测定食品级食盐中的碘酸盐

摘要 用碘酸盐将苯肼氧化成苯基重氮离子，再与 2-萘酚或 8-羟基喹啉偶联生成橙红色偶氮染料，该方法可用于食品级食盐样品中碘酸盐的测定，该方法简单、快速。 . 染料用微升体积的 2-丙醇萃取，当通过添加硫酸铵发生相分离时，该过程称为盐析均相液体微萃取 (SH-LLME)，并进行分光光度法分析。当两种偶联剂 8-羟基喹啉和 2-萘酚产生相对可比的结果时，比较了两种偶联剂在碘酸盐测定方面的相对效率。该方法已针对反应时间、用于相分离的萃取溶剂和盐的类型进行了优化。获得了 0.08-10 mg L-1 碘酸盐的线性校准曲线，相关系数为 0.998，检测限为 16 μg L-1。使用 2-萘酚和 8-羟基喹啉作为偶联剂的食品级盐样品在加标实验中得到了足够的分析，回收率分别为 86.2–114.6（RSD，6.6–12.6 %）和 90.8–111.3（RSD，7.1–12.6 %） ， 分别。SH-LLME 避免了在萃取前对最终测试样品进行 pH 调整，并且可以容忍分别高达 1 和 6 mg L-1 的 Cu(II) 和 Fe(III)。两种试剂的富集因子分别为 21 和 20。6–12.6 %) 和 90.8–111.3（RSD，7.1–12.6 %），分别使用 2-萘酚和 8-羟基喹啉作为偶联剂。SH-LLME 避免了在萃取前对最终测试样品进行 pH 调整，并且可以容忍分别高达 1 和 6 mg L-1 的 Cu(II) 和 Fe(III)。两种试剂的富集因子分别为 21 和 20。6–12.6 %) 和 90.8–111.3（RSD，7.1–12.6 %），分别使用 2-萘酚和 8-羟基喹啉作为偶联剂。SH-LLME 避免了在萃取前对最终测试样品进行 pH 调整，并且可以容忍分别高达 1 和 6 mg L-1 的 Cu(II) 和 Fe(III)。两种试剂的富集因子分别为 21 和 20。