基于双曲面弯晶技术的便携式X射线荧光光谱仪快速测定土壤中(类)金属元素的含量

Rapid Determination of(Metalloid)Metal Elements in Soil by Portable X-Ray Fluorescence Spectrometer Based on Hyperbolic Curved Crystal Technology

为解决常规便携式X射线荧光光谱仪现场检测土壤(类)金属元素时存在的检测元素种类少、部分元素检出限高等缺点,选择GB 15618-2018、GB 36600-2018、农业农村部发布的《第三次全国土壤普查工作方案》包含的重(类)金属元素、金属营养元素以及具有开采价值的(类)金属元素作目标元素,对题示方法的应用可行性(检出限、精密度、准确度)进行了全面考察。土壤样品经烘干、研磨、压实后,用配有双曲面弯晶的便携式X射线荧光重金属分析仪分析,采用快速基本参数法(Fast FP)定量。结果显示:Cd、Hg、As、Cu、Sb、Tl、Mo、Sn、Se、Cs等主要目标元素的检出限为0.2~3 mg·kg^(-1),基本低于环境背景值或上述标准要求的限值(Hg和Se除外)。按照试验方法分析3种水系沉积物成分分析标准物质和两种土壤成分分析标准物质,除测定值在测定下限以下的元素以及Tl、Mg元素外,标准物质中其余主要目标元素测定值的相对标准偏差(n=7)基本低于20%,相对误差的绝对值基本低于35%,Cu、Pb、Cr、Zn和Ni等基础项目元素测定值的相对标准偏差和相对误差符合或接近HJ/T 166-2004对室内平行双样测定精密度和准确度的允许误差要求。利用上述方法分析5种实际土壤样品,所得结果和标准分析方法的基本一致。方法具有快速、准确度高、重现性好,定性、定量元素多的特点,适用于多场合土壤中(类)金属元素的现场测定。

In order to address the shortcomings of limited types of detection elements and high detection limits of some elements in the detection of(metalloid)metal elements in the soil by portable X-ray fluorescence spectrometers,heavy(metalloid)metal elements,metal nutrient elements,and heavy(metalloid)metal elements with mining values included in GB 15618-2018,GB 36600-2018 and the Third National Soil Census Work Plan issued by the Ministry of Agriculture and Rural Affairs were selected as the target elements,and the comprehensive investigation was conducted on the feasibility of the title method's application(detection limit,precision,and accuracy).After drying,grinding,and compaction,the soil samples were analyzed using a portable X-ray fluorescence heavy metal analyzer equipped with the hyperbolic curved crystal,target elements in which were quantified using the fast fundamental parameters(Fast FP).It was shown that detection limits of major target elements(such as Cd,Hg,As,Cu,Sb,Tl,Mo,Sn,Se,Cs,etc.)were in the range of 0.2-3 mg·kg^(-1),which were basically lower than the environmental background values or the limits required by the above standards(excluding Hg and Se).The proposed method was applied to the analysis of 3 sediment composition analysis reference materials and 2 soil composition analysis reference materials.Except for elements with determined values below the lower limit of determination and Tl,Mg elements,RSDs(n=7)of the other major target elements in the reference materials were basically less than 20%,and absolute values of relative errors were basically less than 35%.The RSD and relative error of the elements of Cu,Pb,Cr,Zn and Ni(the basic item elements)met or were close to the allowable error requirements for the precision and accuracy of indoor parallel double sample determination in HJ/T 166-2004.The above method was applied to the analysis of 5 actual soil samples,and the results obtained were basically consistent with those of the standard analysis methods.The proposed method had the characteristics of quickness,high accuracy,good reproducibility,and abundant qualitative and quantitative elements,making it suitable for on-site determination of(metalloid)metal elements in soil in multiple occasions.