Application of laser ablation inductively coupled plasma mass spectrometry for soil analysis: a novel procedure for sample preparation

A rapid, sensitive and reliable LA–ICP–MS method for simultaneous determination of micro and macro elements in soils and sediments was developed and optimized. Certified reference materials available in powder form (IAEA–SOIL–5, IAEA–SOIL–7, IAEA–SL–1, IAEA–SL–3 and STSD–3) were used for the optimization and validation of the sample preparation step and LA–ICP–MS analysis. Three types of soil pellets were prepared from each CRM: (i) original soil; (ii) soil, mixed with boric acid in ratio 1:5; and (iii) pellets, prepared by mixing the soil successively in hexane and dichloromethane and subjected to LA–ICP–MS measurement. The signal of the matrix elements was reduced by introducing the rejection parameter (RPa) to enable the high–mass cut off. Best accuracy and precision were obtained with the pellets, prepared in organic solvents. This approach can be recommended for sample preparation of soils and sediments for LA–ICP–MS analysis. Key words: LA–ICP–MS, pellet preparation, calibration, soil analysis