Rapid Screening of Sulfur Amino Acids in Human Plasma by Ultra Performance Liquid Chromatography-tandem Mass Spectrometry for Diagnosis of Metabolic Disorder

A rapid and simple screening method was developed for the simultaneous analysis of 6 sulfur-containing amino acids from human plasma at ng level. The procedure involves simple protein precipitation followed by direct analysis using UPLC-MS/MS. Calibration curves showed an excellent linear relationship with coefficients of determination (r 2 ) of 0.9989-0.9998. LOD and LOQ were between 1-50 ng/mL and 10-100 ng/mL, respectively. When sulfur amino acids spiked into plasma sample, excellent linearity of detection response was demonstrated over the range between 10-10,000 ng/mL. This new analytical method is suitable for simultaneous screening of large number of samples in clinical application and metabolomics research.