一种新的FIA导数光谱技术测定食盐中碘含量

提出一种新的流动注射导数光谱检测技术,即双光束同时扫描法。将自行研制的流动池比色装置分别安置在双光束检测器中样品光束和参比光束的光路中,实现同时扫描,获得响应曲线为一阶导数光谱。对该方法的原理和实验技术进行了讨论,基于碘酸根与碘化钾生成碘,并与淀粉生成蓝色络合物(λmax=574 nm)原理,确定了最佳实验条件,建立了一种导数光谱法测定加碘食盐中的碘含量。该法分析速度为130次/h,方法灵敏度比普通FIA法提高了1.8倍,测定结果的相对标准偏差为0.97%(n=9),方法可直接用于实际样品中碘含量的检测。

Determining Iodine in Table Salt by a New FIA Derivative Spectra Technology

A new flow injection derivative spectra technology, namely double beam and scanning method, was put forward. The flow pool colorimetric device was placed in the sample beam and the contrast beam of the double beam detector, then it scaned simultaneously and acquired response curves for the first derivative spectra. The principle and experimental technology were discussed based on the technique of iodate and potassium iodine generating iodine, and with the starch generating blue complex （λmax = 574 nm）. The best experimental conditions were defined, and a derivative spectra method was established to determine the content of iodine in table salt with iodine. The method analyzing speed was 130 time/h, the sensitivity was improved by 1.8 times compared with common FIA. The relative standard deviation of detection results was 0.97% （n=9）. The method can be applied directly to detect iodine content in the actual samples.