Application of portable single-wavelength excitation energy dispersive X-ray fluorescence method for rapid detection of heavy metals in soils
The portable single-wavelength excitation energy dispersive X-ray fluorescence(SW-PXRF)method was used to analyze 7 kinds of heavy metals(Cr,Ni,Cu,Zn,Pb,As and Cd)in certified reference materials for soils(from GSS-la to GSS-8a)and contaminated soil samples in Tongling,Anhui.The measurements of contaminated soil samples were compared with those by inductively coupled plasma-mass spectrometry(ICP-MS)method,in order to assess the detection limits,precision and accuracy of this method.Furthermore,the effects of soil moisture content and particle size on the determination were investigated,and the best pretreatment conditions for field test were confirmed.The results showed that the detection limits of soil heavy metals were all lower than 1.3 mg/kg.In particular,the detection limit of Cd was as low as 0.07 mg/kg.The relative standard deviations of the heavy metals were generally below 5％except for Cd,and the mean relative errors were all within the range from-10％to 10％expect for As and Cd.Measurements by SW-PXRF method were highly correlated with those by ICP-MS method,with the determination coefficients more than 0.95 expect for Cr and Ni.Considering that the performance of the measurements were influenced by moisture content and particle size of soil,the pretreatment condition for field test was optimized,thus these two effects mentioned above could be weakened by grinding soil samples for 60 s after drying at 200 ℃ for 6 min.
single-wavelength excitation energy dispersive X-ray fluorescence methodportable X-ray fluorescence spectrometersoil heavy metalsrapid detection
万方数据
维普
