手持式X射线荧光光谱仪（XRF）作为快速筛选重金属污染的手段在污染地块调查中广泛使用，但目前国内对XRF现场检测结果指导实验室筛选检测样品的可靠性研究缺乏。本文选择两个实际污染地块调查中的Cu、Pb、As、Ni、Cd和Hg 6种重金属的XRF现场检测数据和实验室实测数据，采用一元线性拟合、Pearson相关、差异分析等手段对两种测试结果的一致性进行研究。结果表明，土壤中Cu、Pb、As和Ni 4种金属的XRF测定值和实验室实测值具有显著相关性。Hg和Cd的XRF测定值显著高于实验室实测值，Cu、Pb、As和Ni XRF测定值较实验室实测值偏小的样品占比超过50%。6种重金属中Cu和Pb XRF测定值和实验室实测值的相关性及一元线性拟合结果更好（相关系数0.5~0.8，R2>0.7）。Cu在XRF测定值大于1 000 mg/kg时与实验室实测值的拟合结果更好（R2>0.7），As和Pb分别为XRF测定值在4.0~10 mg/kg和检出限~80 mg/kg范围时更好（R2>0.8）。采用重金属筛选值的50%作为筛选实验室样品的标准时，XRF结果预测Cu、Pb和As超标样品的准确度分别为87.5%、100%和67.9%，比直接采用筛选值提高12.5%、66.67%和17.9%。因此，在实际场地应用XRF测试结果筛选实验室检测样品时，可适当降低筛选标准。
Portable XRF is widely applied in the investigation of contaminated sites as a fast-screening tool for heavy metals, but very few studies focused on the assessment of XRF test results to guide the sample selection in laboratory detection. In order to evaluate the guidance of portable XRF in practical applications, the XRF and lab measured data of six heavy metals of Cu, Pb, As, Ni, Cd, and Hg were selected from two sites. The linear fitting, Pearson correlation and differences between XRF and lab values were analyzed. The results showed that there was a significantly positive correlation between XRF and lab data in Cu, Pb, As and Ni. XRF data of Hg and Cd were higher than those of lab data, while the values of Cu, Pb, As and Ni detected by XRF were smaller than those of lab data with more than 50% of the samples. Among the six heavy metals, Cu and Pb performed better in the correlation analyzed and linear fitting results between XRF and lab data (correlation coefficient=0.5-0.8, R2>0.7). Moreover, Cu had better fitting results between XRF and lab data in XRF data high than 1 000 mg/kg (R2>0.8), the better fitting results of As and Pb were found in the range of 4.0-10.0 mg/kg and the detection limits to 80 mg/kg respectively. Furthermore, when the half screening values of heavy metals were used as the standard for selecting lab samples, the accuracy of predicting contaminated samples by XRF in Cu, Pb and As were 87.5%, 100%, and 67.9% respectively, which were an increase of 12.5%, 66.67% and 17.9% comparing to direct use of the screening values. Therefore, the screening criteria should be appropriately lowered in selecting lab detection samples when using XRF data in investigating contaminated sites.
陈云,应蓉蓉,孔令雅,姜登登,李旭伟,夏菲洋,丁达,龙涛,邓绍坡.手持式X射线荧光光谱快速测定仪的实践应用评价及建议[J].土壤,2022,54(3):586-593. CHEN Yun, YING Rongrong, KONG Linya, JIANG Dengdeng, LI Xuwei, XIA Feiyang, DING Da, LONG Tao, DENG Shaopo. Assessment and Suggestions of Application of Field Portable XRF in Investigating Contaminated Sites[J]. Soils,2022,54(3):586-593复制