《饲料中碘的测定》硫氰酸铁-亚硝酸催化动力学法国家标准前处理方法修订解读

Revised interpretation of the pre-treatment method of ferric thiocyanate-nitrite catalytic dynamic method in the national standard of "Determination of iodine in feeds"

对修订的GB/T 13882—2023《饲料中碘的测定》第二法硫氰酸铁-亚硝酸催化动力学法的关于前处理的修订内容进行了解读。该方法相较之前更改了碘标准工作溶液的配制方式、干灰化法并删除了湿法。采用580℃灰化样品,使试样中的碘酸根转换为碘离子,同时使用580℃处理碘标准中间溶液,补偿样品前处理过程中碘的损失。相较于修订前,修订后的前处理样品方法和配制标准系列曲线方式能显著提高方法的准确性。

In the revised GB/T 13882—2023 "Determination of iodine in feeds",the revised content of the second method of ferric thiocyanate-nitrite catalytic dynamic method on pre-treatment was reviewed.Compared with the previous method,the preparation method of iodine standard working solution,dry ashing method and wet method were changed.The iodate radical in the sample was converted to iodide by ashing the sample at 580℃,and the iodine standard intermediate solution was treated at 580℃ to compensate for the iodine loss during the sample pretreatment.Compared with before the revision,the revised pre-treatment sample method and the standard series curve preparation method can significantly improve the accuracy of the method.