Determination of 15 Trace Elements in Soil Samples by LA-ICP-MS

Rhenium as internal standard element was added to the soil standard sample, and the sample was injected directly after pressing into tablet. Laser beam was focused at 100 μm below the sample surface, and LA was performed as follows: 1 the flow rate of helium as carrier gas was 600 mL·min^-1; 2 the diameter of ablation light spot was 110 μm; 3 the ablation rate was 50 μm·s^-1. The ablation particles obtained were introduced into ICP-MS and 15 trace elements (i.e. Be, V, Cr, Co, Ni, Cu, Zn, Ga, As, Cd, Sn, Sb, Tl, Pb, Bi) were determined. The standard addition method was used to extrapolate to obtain the content of target elements by the calibration curve. Detection limits (3s) found were in the range of 0.01-0.08 μg·g^-1. Two soil standard samples (GSS-3 and GSS-14) were analyzed by this method. Except for Be, Sb and Cd, the determined values of other elements were all within the allowable uncertainty ranges of the certified values, with relative error (RE) less than 10%; the soil standard sample (GSS-14) was analyzed for 5 times, and RSDs (n=5) of the measured values of 15 elements were all within 10%.