Determination of 22 Metals in Soil by ICP-MS Based on Different Pretreatment Methods
With the use of tetraacid digestion system(HNO3-HCl-HF-HClO4),microwave digestion and electrothermal plate heating were applied for the digestion of various real soil samples,followed by inductively coupled plasma mass spectrometry(ICP-MS)detection.The proposed method was used for the determination of Ag,As,Ba,Be,Bi,Cd,Co,Cr,Cu,Li,Mn,Mo,Ni,Pb,Sb,Sn,Sr,Th,Tl,U,V and Zn in soil under the optimized sample mass,reagent dosage,digestion temperature/time,and instrumental operation conditions.The detection limits of 22 target elements obtained by ICP-MS with the use of microwave digestion and electrothermal plate heating were 0.01-3.0 mg/kg and 0.01-2.0 mg/kg,with the limit of quantification of 0.04-12.0 mg/kg and 0.04-8.0 mg/kg,respectively.The linear correlation coefficient(r)of the calibration curve ranges from 0.9992 to 0.9999 and the calibration curve intermediate point concentration measurement deviation ranges from-6.3%to 9.1%in the concentration range of 0-500 μg/L.The relative standard deviation ranges were 0.3%-19.9%and 0.3%-18.4%respectively.The relative error ranges were-18.5%-15.8%and-20.6%-11.9%in different contents gradient reference materials soils,respectively.The method characteristic index can meet the quality assurance and quality control requirements.The ICP-MS detection can achieve rapid qualitative and accurate quantitative detection of 22 metals in soil,which can provide technical support and has broad application prospects for batch analysis of multiple metals.
SoilHeavy metalsElectrothermal plate digestionMicrowave digestionInductively coupled plasma mass spectrometry