Determination of the Contents of 12 Elements in Millet by Microwave Digestion and Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

Microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS) were used to simultaneously determine the contents of various elements in millet. After the microwave digestion with nitric acid, the mass spectral interference was eliminated by optimizing the instrument parameters and adopting the collision/reaction tank (ORS) technology, and the internal standards were added online to correct the matrix interference and drifting. The contents of Ca, Mg, Fe, Mn, Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in millet were determined by ICP-MS. The results showed that the linear relationship of the 12 elements was good, the correlation coefficient r was all greater than 0.9995, the adding standard recovery was 90.0%-102.2%, and the relative standard deviation (RSD) was all less than 6.6%. The results were verified by using national standard substance rice (GBW10010) and wheat (GBW10011), which was accurate and reliable. The results showed that the method was accurate, rapid, simple and sensitive, and was suitable for the simultaneous determination and analysis of the contents of various elements in millet.