Establishment and Performance Evaluation of Candidate Reference Measurement Procedures for the Detection of Serum 25(OH)D3 Based on Isotope Dilution Liquid Chromatography Tandem Mass Spectrometry / 现代检验医学杂志

ABSTRACT

Objective To establish a candidate reference measurement procedure for the detection of serum 25-hydroxy vitamin D3[25(OH)D3]based on isotope dilution liquid chromatography tandem mass spectrometry(LC-MS/MS).Methods Isotope standard solution was used as internal standard,liquid-liquid extraction was used for pre-treatment,and positive ion electrospray ionization mode was used for monitoring.The accuracy,precision,linear range,limit of quantitation,detection limit and relative matrix effect of method were verified based on documents of the America Clinical and Laboratory Standards Institute(CLSI)such as C62-A and EP15-A3.Candidate reference measurement procedure and mass spectrometry routine procedure were used to detect 40 clinical serum samples,and to evaluate the consistency of the two methods.Results The analysis time of the candidate method was 15 min.Isometric elution of chromatography was used to effectively separate the isomer 3-epi-25(OH)D3,with good specificity.RELA comparison sample was measured,with a bias of less than 1.5%.The intra-batch precision and inter-batch precision ranged from 0.75%to 2.31%and 1.28%to 2.01%,respectively.The limits of quantification and detection were 0.85 ng/ml and 1.84 ng/ml.It had good linearity in the concentration range of 2.5～220 ng/ml,and there was no relative matrix effect and carrier contamination.The correlation between the mass spectrometry routine procedure and candidate reference procedure was good(r=0.982),while the deviation at low concentration samples exceeded the allowable total error±25%in the external quality assessment of the National Center for Clinical Laboratories.Conclusion A candidate reference measurement procedure for serum 25(OH)D3 technology based on LC-MS/MS was successfully established,and the analytical performance met the requirements,which could be used for quantitative traceability by clinical conventional methods.