The determination of potassium in human serum by isotope dilution inductively coupled with plasma mass spectrometry / 中华检验医学杂志

ABSTRACT

Objective To establish a method for the determination of serum potassium using isotope dilution inductively coupled plasma mass spectrometry.Methods Frozen human serum pools of different potassium concentrations were prepared from healthy donors of Chao-yang Hospital laboratory in 2010 Serum samples were diluted with 1％ HNO3 supplemented with 41K spike and isotope ratio was measured after selection and optimization of ICP-MS analysis conditions.Serum 39K concentrations were calculated by interpolation method.3 different serum samples were used to evaluate the precision of the method.Standard Reference Material 909b Ⅰ and Ⅱ of National Institute of Standards and Technology were used to evaluate the accuracy.The recovery was evaluated through 2 serum samples added standard material for potassium,uncertainty was calculated.Results The analytical precision of serum potassium measurement was 0.14％ to 0.11％.The results of SRM909b Ⅰ and Ⅱ gave the coefficients of variation (CVs) of 0.39％ to 0.32％.Data was consistent with the certified value and the CV was + 0.12％ and + 0.49％ respectively.The recovery was 99.68％ to 100.12％ for 2 different serum samples.Conclusions ID-ICP-MS method was successfully established to measure the serum potassium concerntration precisely and accurately,it is an ideal method for the accurate determination of inorganic elements.