title: Direct tandem mass spectrometric analysis of amino acids in dried blood spots without chemical derivatization for neonatal screening.
abstract: Neonatal screening performed by electrospray tandem mass spectrometry is a powerful technique in clinical diagnostics. In the present paper an alternative to the widely accepted method involving butylation has been developed. In the new method butylation is not required, and multiple reaction monitoring (MRM) was used instead of constant neutral loss scanning. The method was optimized for detection of 23 L-amino acids in their native form. Quantitation was based on isotope-labeled internal standards, calibration curves were linear from 0 to 500 micromol/L, and detection limits were in the range 2-42 micrmol/L. The utility of the present technique is illustrated in the case of one neonate suffering from citrullinaemia.
authors.affiliation: Institute of Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, H-1025 Pusztaszeri ut 59-67, Budapest, Hungary.
authors.forename: Kornél
authors.initials: K
authors.lastname: Nagy
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Takáts
authors.forename: Ferenc
authors.initials: F
authors.lastname: Pollreisz
authors.forename: Teréz
authors.initials: T
authors.lastname: Szabó
authors.forename: Károly
authors.initials: K
authors.lastname: Vékey
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000097:blood; D000596:Amino Acids / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D007231:Infant, Newborn; D013058:Mass Spectrometry; D015997:Neonatal Screening / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results; D014462:Ultrafiltration
chemical_list: D000596:Amino Acids; D007202:Indicators and Reagents