RESUMO
Objective:To establish a candidate reference method for the determination of angiotensin Ⅱ in human plasma by isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS) and to evaluate its performance.Methods:Using [ 13C 6- 15N]-angiotensin Ⅱ as the internal standard, the plasma was accurately weighed by gravimetric method and mixed with a certain amount of internal standard. At the same time, enzyme inhibitor was added. After zinc sulfate solution protein precipitation and reversed-phase solid-phase extraction plate treatment, it was analyzed by liquid chromatography tandem mass spectrometry. The multi reaction ion monitoring mode(MRM)was selected by mass spectrometry to detect specific ion fragments of angiotensin Ⅱ and internal standard. The linearity, sensitivity, precision, recovery rate and uncertainty of the performance of the established method were evaluated according to ISO15193. Results:Angiotensin Ⅱ had good linearity in the range of 10-1 000 pg/g ( r=0.999 5), the lower limit of quantification was 7.68 pg/g, the analytical recoveries were 97.14% to 102.85%, intra-batch imprecision≤3.21%, inter-batch imprecision≤2.96%, and total imprecision≤3.67%. Conclusion:A method for the determination of plasma angiotensin Ⅱ was established by ID-LC-MS/MS. The method is accurate and reliable, and is expected to be a reference method for the determination of plasma angiotensin Ⅱ.