Determination of 16 Mineral Elements in Pine Nut by Total Reflection X-ray Fluorescence Spectrometry

A method of total reflection X-ray fluorescence spectrometry for the determination of 16 mineral elements, i.e. K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr and Pb, in pine nuts was proposed. The pine nut sample was digested with MWS-2 microwave digestion system for 50 min at 180 ℃. Gallium was used as internal standard. Detection limits of the elements were found in the range of 0.003-0.142 mg·kg-1. In the analysis of the CRM of pollen (GBW 10026) by this method, results obtained were in consistency with the certified values. The pine nut sample was analysed by the proposed method and the ICP-MS method. It was found that there was no significant difference between the results obtained by the 2 methods. Values of RSD′s (n=6) of the results found by the proposed method were in the range of 0.8%-4.7%.