Development and validation of a fast quantitative method for plasma dimethylarginines analysis using liquid chromatography-tandem mass spectrometry.

Objectives: The aim of this work was to implement a fast, accurate and simple method to quantify plasma ADMA and SDMA, in a run time suitable for routine analysis.
Design and Methods: We developed and validated a hydrophilic interaction chromatographic method coupled to tandem mass spectrometry (HILIC-MS/MS) for separation and simultaneous quantification of Arginine (Arg) and its dimethylarginines, ADMA and SDMA, with a short run time (less than 5 min) using a small volume of human plasma (0.02 mL).
Results: Correlation coefficients (r) of the calibration curves ranged from 0.9926 to 0.9984. Within-day and between-day imprecision (CV%) and inaccuracy (%), carry-over and recovery were also evaluated for validation. Preliminary data of Arg, ADMA and SDMA from 30 apparently healthy subjects and type 2 diabetic patients (n=33) with and without kidney dysfunction were calculated and some statistical differences occurred among them (p<0.05).
Conclusions: Data from calibration curves and quality controls reveal that the method is accurate and precise. Healthy subjects and diabetic patients' values are in agreement with those reported in other studies.