Simultaneous gas chromatography-tandem mass spectrometry quantification of symmetric and asymmetric dimethylarginine in human urine.

Previously, we demonstrated the utility of a gas chromatography-tandem mass spectrometry (GC-MS/MS) method for the quantitative determination of asymmetric dimethylarginine (ADMA) in biological samples. Here we report the extension of this method to symmetric dimethylarginine (SDMA) in human urine. SDMA and ADMA were simultaneously quantitated in urine by using their in situ prepared trideuteromethyl esters as internal standards. The GC-MS/MS method was validated for SDMA and ADMA in spot urine samples of 19 healthy adults. In these samples, the creatinine-corrected excretion rate was 3.23±0.63 µmol/mmol for SDMA and 3.14±0.98 µmol/mmol for ADMA.