Determination of magnesium in serum by inductively coupled plasma mass spectrometry

Abstract

Objective To develop a candidate reference method for the determination of magnesium in serum by inductively coupled plasma mass spectrometry method (ICP-MS). Methods Aluminum was selected as internal standard of magnesium and spiked gravimetrically into magnesium standard solutions and serum samples.Then the 24Mg/27Al isotope ratios of digested and diluted samples were obtained by ICP-MS,the magnesium concentrations in serum were calibrated basing on the bracketing method. Results The analytical recoveries for 2 samples were 100.22% and 100.11% respectively (n=3).The precision for 3 samples were 0.35%,0.36% and 0.41% respectively (n=9).The results on Standard Reference Materials SRM909b and SRM956b gave excellent agreement with the certified values.The results of SRM909b gave the coefficients of variation (CV) of 0.54% and 0.53% for 2 samples,and the results of SRM956b gave 0.30%,0.50% and 0.47% for 3 samples.The method has been successfully applied to the RELA inter-laboratories comparison. Conclusions The ICP-MS method is proved to be not only precise and accurate,but also quick and convenient for measuring magnesium in serum.It is promising to be a candidate reference method.(Chin J Lab Med,2013,36:738-742) Key words: Magnesium; Mass spectrometry; Spectrophotometry; atomic