Standard practices of quantitation using liquid chromatography-tandem mass spectrometry (LC-MS/MS) follow techniques such as multiple reaction monitoring (MRM) that allow for precursor ions to be selected within a tradition 1 Da isolation window and a product ion is targeted for quantitation after fragmentation. This method works well for targeted analysis that requires high sensitivity, but relevant data within the acquisition is not sufficiently preserved to undergo global metabolomics processing due to insufficient scan speeds. With lower scan speeds, peak shapes deteriorate greatly due to the lack of data points within a chromatographic peak. In past methods, wide isolation MS/MS has been used to incorporate the targeted analyte and internal standard for the purpose of stability in fragmentation with ambient ionization techniques. In addition to increased reproducibility, an increased scan rate allows for a more dynamic data acquisition that does not limit the analysis to a targeted method when paired with a chromatographic method. Our study is focused on using wide isolation (12 Da) MS/MS for the quantitation of six tryptophan degradation metabolites for the purpose of identifying potential links to gut microbiome to the brain in a rat study. The experiment consisted of three dieatary states including control chow, tryptophan supplemented, and tryptophan deficient diet. The goal is to determine potential links between tryptophan processing in the gut to potential metabolites such as serotonin or kynurenine that can be indicators for things such as neurodegenerative disorders and immune activation.

Quantitation of tryptophan degradation products using wide isolation MS/MS via UHPLC-HRMS/MS

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.