Direct infusion mass spectrometry(DIMS) is a powerful technique in clinical diagnosis for screening neonatal amino acid metabolic disorders from dried blood spots(DBS).However,DIMS sometimes generated false-positive r...Direct infusion mass spectrometry(DIMS) is a powerful technique in clinical diagnosis for screening neonatal amino acid metabolic disorders from dried blood spots(DBS).However,DIMS sometimes generated false-positive results for analysis of amino acids.In this work,we utilized a stable isotope derivatization method,combining with liquid chromatography tandem mass spectrometry(SID-LC-MS),to improve the specificity for screening amino acids in DBS specimens.A pair of isotope reagents,p-(dimethylamino)phenyl isothiocyanate(DMAP-NCS) and 4-isothiocyanato-N,N-bis(methyl-[2H2])aniline([2H4]DMAP-NCS),was synthesized and used to label amino acids in DBS specimens.The [2H4]DMAP-NCS labelled amino acid standards were used as internal standards to compensate the matrix effect.This method was validated by measuring linearity,recovery and accuracy.The results showed that the developed SID-LC-MS method can be used for sensitive and selective determination of 12 diagnostically important amino acids in DBS specimens.展开更多
基金supported by the National Key R&D Program of China(No.2018YFA0900400)the National Natural ScienceFoundation of China(Nos.21635006,31670373,21721005,21904099)the Postdoctoral Science Foundation of China(No.2018M642893)。
文摘Direct infusion mass spectrometry(DIMS) is a powerful technique in clinical diagnosis for screening neonatal amino acid metabolic disorders from dried blood spots(DBS).However,DIMS sometimes generated false-positive results for analysis of amino acids.In this work,we utilized a stable isotope derivatization method,combining with liquid chromatography tandem mass spectrometry(SID-LC-MS),to improve the specificity for screening amino acids in DBS specimens.A pair of isotope reagents,p-(dimethylamino)phenyl isothiocyanate(DMAP-NCS) and 4-isothiocyanato-N,N-bis(methyl-[2H2])aniline([2H4]DMAP-NCS),was synthesized and used to label amino acids in DBS specimens.The [2H4]DMAP-NCS labelled amino acid standards were used as internal standards to compensate the matrix effect.This method was validated by measuring linearity,recovery and accuracy.The results showed that the developed SID-LC-MS method can be used for sensitive and selective determination of 12 diagnostically important amino acids in DBS specimens.
