The Usefulness of High-Resolution LC-TOF MS in Metabolic Disorder Screening

In phenylketonuria, analyzing the blood concentrations of Phe and its metabolite Tyr is crucial. It was concluded that LC-TOF MS has advantages over traditional LC-MS/MS for this purpose.

Using an Agilent 6550 TOF system with an Intrada Amino Acid (50x3mm) column and comparing it with an API4000 (MS/MS) using the aTRAQ™ kit for amino acid analysis, the following results were obtained:

1. For 10-minute and 1-minute analyses using TOF MS, excellent values were obtained with retention time within ±0.05 minutes and mass accuracy within ±15 ppm.

2. The correlation of Phe dilution sample analysis values between the two systems was generally good.

3. For DL-β-amino-n-butyric acid, the LC-TOF MS system showed retention time within ±0.05 minutes and mass accuracy within ±17 ppm, whereas LC-MS/MS failed to detect 30% of the standard samples.

It was found that the LC-TOF MS method using the non-derivatized amino acid analysis column Intrada Amino Acid is operationally simpler and provides similar analysis values compared to the derivatized LC-MS/MS method. Unlike LC-MS/MS, there is no need to consider the fragmentation conditions for product ions, and high accuracy can be achieved with just the precursor ions. Therefore, LC-TOF MS was concluded to be very useful for screening tasks.

High-resolution LC-TOF MS and The Intrada Amino Acid column provide a simple and rapid technique for screening amino acids in metabolic disorders.

• MSACL2017 POSTER
  

  (Courtesy of Julie A. Ray, ARUP Institute for Clinical and Experimental Pathology, University of Utah, USA)