High Efficiency Determination of Trace Elements in the Geological Samples

A method for determining 34 trace elements in deep-sea marine sediments and international geological samples by ICP-MS was proposed. Samples were digested in anticorrosive efficient digestion vessel, which had a double inner arc seal design. The internal standard ¹⁰³Rh was used to calibrate the trace element concentrations, and the internal standard ¹⁸⁵Re was selected to compensate the drift of analytical signals. Compared with previous digestion methods, this method used less acid in a good seal condition, only 1.5 mL HF, 0.5 mL HNO₃ and 0.25 mL HClO₄ can digest 40 mg geological samples completely in a short time. Because the internal standard ¹⁰³Rh was added during the pre-treatment process, so there was no need to dilute the digested sample to an accurate volume, and thus saved a lot of time. This method detection limits are 0.001—0.621 μg/g, the determination precisions (RSD, n=10) are less than 6.5%, and the relative errors between this work and the recommend values are less than 5%, in which most are less than 3%. This method can meet the requirements for analyzing a large number of trace elements in many geological samples.