Determination of 32 Characteristic Components in the Black Soil from Northeast China by Inductively Coupled Plasma Spectroscopy and Mass Spectrometry after Melting with Lithium Metaborate

The methods for determination of the 32 characteristic components in the black soil from Northeast China by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) after melting with lithium metablrate were established. After drying, grinding and sifting through 0.074 mm sieve, 0.100 0 g of black soil sample and 0.3 g of lithium metaborate were mixed in a graphite crucible,and melted in a high temperature furnace at 1 000℃ for 20 min, and then poured immediately into a 100 mL beaker containing 20 mL of a mixture of nitric acid-hydrochloric acid-water at volume ratio of 1:3:76. Ultrasound was used until the melt was dissolved completely, and the volume of the solution was made its volume up to 100 mL. The 32 characteristic components in the solution were determined by ICP-AES and ICP-MS simultaneously. As shown by the results, the linear correlation coefficients of the standard curves of the 32 characteristic components were all above 0.999 7 and the detection limits (2.764s) were in the range of 0.01-46.82 μg·g^-1. National standard substances (GBW 07401, GBW 07424 and GBW 07425) were determined by this method, and the determined values of the 32 characteristic components were basically consistent with the certified values, with relative errors in the range of -6.1%-4.7% and RSDs (n=10) of the determined values in the range of 0.67%-5.4%. And this method was applied to analyzing the actual samples of black soil.