Study On Determination Of Inorganic Components In Human Blood Serum Standard Reference Material

Electrolytes in serum are important biomarkers for skeletal and cellular health. The levels of electrolytes are monitored by measuring the K, Ca, Mg, and Li in human blood serum. Many reference methods have been developed for the determination of K, Ca, Mg, and Li in clinical measurements; however, isotope dilution thermal ionization mass spectrometry (ID-TIMS) has traditionally been the primary reference method serving as an anchor for traceability and accuracy to these secondary reference methods. The sample matrix must be separated before ID-TIMS measurements, which is a slow and tedious process that hindered the adoption of the technique in routine clinical measurements.Contents in this work can be listed as follows:(1) The chlorides solution were added into the human blood serum to achieve high, medium and low levels. The selected target elements are:K, Ca, Na, Mg, Li and Cl;(2) Compared the ability of two reaction/collision gas H2 and NH3 on eliminate spectral interferences of determination of K, Ca, Mg and Li in human blood serum by ICP-MS. Optimization of instrument by introduced a mixed standard solution for RF power, reaction/collision gas flow, and RPq parameters to achieve an optimum measurement condition;(3) Developed an accurate method for the determination of K, Ca, Mg and Li in human blood serum by taking advantage of the "cold" plasma mode and collision reaction cell of the isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS). The proposed method eliminated the need for a slow and tedious sample digestion procedure, and avoided the molecular ions interferences;(4) National institute of standards and technology standard reference material 956c level2 inorganic components in frozen human serum, laboratory of the government chemist standard reference material ERM-DA250a frozen human serum and national institute of metrology standard reference material GBW09152 were analyzed by the method and the measured elements values were in good accord with the standard values.