Open AccessQuantitative amino acid analysis by liquid chromatography‐tandem mass spectrometry using low cost derivatization and an automated liquid handler
Author(s) -
Phipps William S.,
Crossley Eric,
Boriack Richard,
Jones Patricia M.,
Patel Khushbu
Publication year - 2020
Publication title -
jimd reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.412
H-Index - 25
ISSN - 2192-8312
DOI - 10.1002/jmd2.12080
Subject(s) - chromatography , derivatization , chemistry , analyte , reagent , liquid chromatography–mass spectrometry , ninhydrin , mass spectrometry , tandem mass spectrometry , calibration curve , sample preparation , high performance liquid chromatography , amino acid , detection limit , organic chemistry , biochemistry
Abstract Amino acid analysis is central to newborn screening and the investigation of inborn errors of metabolism. Ion‐exchange chromatography with ninhydrin derivatization remains the reference method for quantitative amino acid analysis but offers slow chromatography and is susceptible to interference from other co‐eluting compounds. Liquid‐chromatography tandem mass spectrometry (LC‐MS/MS) provides a rapid and highly specific alternative, but sample preparation is frequently laborious and sometimes cost prohibitive. To address these limitations, we validated an LC‐MS/MS method using the aTRAQ Reagents Application Kit with a modified protocol consuming only half reagents. Adequate performance for clinical specimen measurement of 26 amino acids with high clinical relevance was achieved. An automated liquid handler and modified calibration and normalization approaches were used to ensure reproducible assay performance. Linear measurement between 5 and 2000 μM was achieved for most analytes despite use of a small, 10 μl sample size. Overall the method achieved near substantially improved throughput and enabled use of smaller samples volumes for batched analyses of clinical samples.