单色聚焦X射线荧光光谱法测定粮食中镉、铅、砷

Rapid Determination of Cadmium,Lead and Arsenic in Grain by Monochromatic Focused X-ray Fluorescence Spectrometry

为建立以单色聚焦X射线荧光光谱法快速测定粮食中的镉、铅、砷检测方法为基础,设定粮食中镉、铅、砷限值的判定区间,以期为监管提供筛查依据,本文采用单色聚焦X射线荧光光谱法快速测定粮食中镉、铅、砷含量,并将这种方法与电感耦合等离子体质谱法(ICP-MS)进行比较。前处理样品粒径粉碎粒径<380?滋m;X射线荧光光谱法镉、铅、砷检出限分别为0.0231 mg/kg、0.0588 mg/kg、0.0417 mg/kg;设立判定区间为当结果(w)<60%限量或w>140%限量时,以300 s初测结果进行结果判定,当结果为60%限量≤w≤140%限量时,以600 s复测结果平均值进行结果判定、仪器准确性、重复性以及稳定性等条件均符合要求。可见单色聚焦X射线荧光光谱法操作简单方便、灵敏度高、无环境污染、可应用于粮食类食用农产品现场快速筛查,防止镉、铅、砷超标的粮食流入市场,对粮食监管具有重要意义。

Based on the rapid determination of Cd,Pb and As in grain by monochromatic focused X-ray fluorescence spectrometry,the determination range of Cd,Pb and As limits in grain was set,in order to provide a screening basis for supervision.The content of cadmium,lead and arsenic in grain was determined by monochromatic focused X-ray fluorescence spectrometry,the method was compared with ICP-MS.The particle size of the pre-treated sample is less than 380um;the detection limits of Cd,Pb and As by X-ray fluorescence spectrometry were 0.0231 mg/kg,0.0588 mg/kg and 0.0417 mg/kg,respectively.The determination interval was set as follows:when the result(w)<60%limit or W>140%limit,the result was determined by the initial test result of 300 s;when the result was 60%limit≤W≤140%limit,the average value of the retest result of 600 s was used for the result determination.The accuracy,repeatability and stability of the instrument meet the requirements.Monochromatic focused X-ray fluorescence spectroscopy is easy to operate,sensitive and pollution-free.It can be applied in the field rapid screening of grain edible agricultural products to prevent the cadmium,lead and arsenic exceeding the standard of grain from entering the market,which is of great significance to grain supervision.