便携式X射线荧光光谱法在化肥砷、隔、铅、铬、汞快速检测中的应用

为评估便携式X射线荧光光谱法(PXRF)对化肥中砷、隔、铅、铬、汞五种重金属含量测定的可靠性,使用PXRF法分别对4个模拟污染化肥样品,以及在全国11个省、直辖市或自治区抽样的103个化肥样品进行测定,与肥料检测国家标准(GB/T 23349-2020)中实验室分析方法的测定结果进行了比较。结果表明：PXRF法对模拟污染化肥样品中As、Cd、Pb元素测定的准确度在90% ~ 115%之内,相对标准偏差小于10%,对Cr的测定准确度在115% ~ 140%之间,相对标准偏差在3.99% ~ 15.83%之间,对Hg的测定准确度在70% ~139%之间,相对标准偏差在3.68% ~ 9.37%之间。PXRF法测定的结果与实验室分析法所确定的参考值有较好的相关性,R2 在0.8906 ~ 0.9816之间,PXRF法各元素的最低检出含量低于国家标准限值或与之相当。因此PXRF法能满足肥料中五种重金属含量的快速筛查要求,可作为辅助手段用于肥料重金属污染抽查,有效减少抽样量,提高抽样效率。

Application of Portable X-ray Fluorescence Spectrometry in Rapid Determination of As, Cd, Pd, Cr, Hg in Chemical Fertilizer

In order to evaluate the reliability of portable X-ray fluorescence spectrometry (PXRF) method for determination of As, Cd, Pd, Cr, Hg in chemical fertilizers, four simulated polluted chemical fertilizer samples and 103 chemical fertilizer samples collected from 11 provinces, municipalities or autonomous regions were determined by PXRF method. The results were compared with the results of laboratory analysis methods in the national standard (GB / T 23349-2020). The results show that the accuracy of PXRF method for the determination of As, Cd and Pb in simulated polluted fertilizer samples is within 90% ~ 115%, the RSD is less than 10%, the accuracy of Cr is within 115% ~ 140%, the RSD is within 3.99% ~ 15.83%, the accuracy of Hg is within 70% ~ 139%, the RSD is within 3.68% ~ 9.37%. The results determined by PXRF method and laboratory analysis methods had significant correlations, with the R2 within 0.8906 ~ 0.9816. The LDQ of each element by pxrf method is lower than or equivalent to the national standard limit. Therefore, PXRF method can meet the requirements of rapid determination of five heavy metals in fertilizers. It can be used as an auxiliary method for inspection of heavy metal pollution in fertilizers, effectively reduce the sample size and improve the sampling efficiency.