Abstract: A simple, sensitive and fast high-performance liquid chromatography-mass spectrometry method was developed for simultaneous separation and determination of L-arginine(ARG), asymmetric N^G,N^G-dimethylarginine(ADMA) and symmetric N^G,N′^G-dimethylarginine(SDMA) in human plasma. An APCI interface and the selective ion monitoring(SIM) mode were used. Satisfactory separation was achieved on a 2.0 mm×150 mm Shimadzu VP-ODS column by using the mobile phase consisting of water(95%), acetonitrile(5%) and trifluoroacetic acid(TFA, 0.4%). L-Homoarginine was used as the internal standard for the assay. The total LC-APCI-MS analysis time was less than 5 min. The limits of quantification(LOQ) were found to be 0.2 μmol/L for ARG, ADMA and SDMA. The inter- and intra-assay precisions were in the range of 2.9%—6.7% and 2.1%—5.2%, respectively. The recoveries were between 94.0% and 105.0%. The levels of ARG, ADMA and SDMA in human plasma were determined with the developed method and the results were satisfactory.

Key words: HPLC, MS, APCI, L-Arginine, Plasma