Simultaneous Determination of Trace Elements and Major Elements in Food by ICP-MS Using Microwave Digestion for Sample Preparation

An inductively coupled plasma mass spectrometric (ICP-MS) method based on quadrupole reaction/collision (DRC) was developed for the determination of K, Na, Ca, Mg, Al, Cu, Zn, Pb, As and Mn in food. Samples were digested with HNO3 and H2O2 followed by dilution with ultrapure water and then analyzed directly by ICP-MS. The signal sensitivity of high concentration element (K, Na, Ca, Mg and Al) was suppressed easily by adjusting the voltage parameters of DRC quadrupole (Rpa), and the food samples could be online diluted any multiples (i.e. from one time to million times) according to the actual need. In order to eliminate mass spectral interferences of (ArCl+)-Ar-40-Cl-35, the operational conditions of the DRC, working with CH4 as reaction gas, were optimized for As-75. The limits of detection for the K, Na, Ca, Mg, Al varied from 0.013-0.027 mg/L, and Cu, Pb, Zn, As, Mnvaried from 0.12-0.61 mu g/L. The accurate and reliable results were obtained for validation of the ICP-MS method with food reference material according to the national standard GBW10023, GBW10015, GBW10018, GBW10017, GBW10019 and GBW10024. As the routine method in our laboratory, the satisfactory results indicate that it has great potential for the determination of low and high concentration level elements by one single analysis in various samples.