Use of Ion Chromatography/Mass Spectrometry for Targeted Metabolite Profiling of Polar Organic Acids

Abstract

Organic acids (OAs) serve as metabolites that play pivotal roles in a host of different metabolic and regulatory pathways. The polar nature of many OAs poses a challenge to their measurement using widely practiced analytical methods. In this study, a targeted metabolomics method was developed using ion chromatography/triple quadrupole mass spectrometry (IC/MS) to quantitate 28 polar OAs with limits of quantitation ranging from 0.25 to 50 μM. The interday assay precisions ranged from 1% to 19%, with accuracies ranging from 82% to 115%. The IC/MS assay was used to quantitate OAs in quadriceps muscle from sedentary mice compared to fatigued mice subjected to either a low intensity, long duration (LILD) or high intensity, short duration (HISD) forced treadmill regimen. Among the OAs examined, significant differences were detected for hippuric acid, malic acid, fumaric acid, and 2-ketoglutaric acid between the sedentary and fatigued mice. In conclusion, the IC/MS method enabled the separation and quantitative survey of a broad range of polar OAs that are difficult to analyze by chromatographic techniques.

Applications of chromatography-ultra high-resolution MS for stable isotope-resolved metabolomics (SIRM) reconstruction of metabolic networks

“…A much-overlooked need for metabolomics in general has been the analysis of inorganic anions such as nitrate, nitrite, sulfate, and phosphate, and the current IC implementation also accomplishes this task simultaneously with separation of the polar organic metabolites. The IC-UHR-MS method has been successfully applied to analysis of a large number of charged metabolites and their isotopologues, including amino/organic acids, glutathione, sugar phosphates, nucleotides, inorganic anions, and sugar nucleotides [18,22,71,[89][90][91][92][93][94], as stated earlier currently totaling >14,500 targeted analytes per injection.…”

Anion-Exchange Chromatography Coupled to High-Resolution Mass Spectrometry: A Powerful Tool for Merging Targeted and Non-targeted Metabolomics

“…In this work, we address a merged workflow based on anion-exchange chromatography (IC) in combination with high-resolution MS detection. Anion chromatography proved to be a valuable separation method for key metabolites of the primary carbon metabolome, − offering an alternative to the state of the art strategies based on gas chromatography (GC) and ion pairing LC. − GC is unrivalled regarding the selectivity of the separation of sugars and sugar phosphates, however, falls short when nucleotides are of interest. Compared to IC-MS, LODs in GC-MS/MS are on average somewhat higher (factor of 2–10), e.g., for sugar phosphates LODs ranging between 1 and 200 fmol were obtained by GC-MS/MS .…”

The role of the metabolite cargo of extracellular vesicles in tumor progression

“…Gas chromatography-mass spectrometry (GC–MS), liquid chromatography-mass spectrometry (LC–MS), and capillary electrophoresis-mass spectrometry (CE-MS) are the most common mass spectrometric methods used for metabolomic analyses. Additionally, in recent years, improved analytical techniques have emerged, such as ion chromatography-mass spectrometry (IC-MS) to analyze highly hydrophilic compounds [ 35 , 36 ] or the capillary IC-MS as a selective and specific method to analyze anionic metabolites [ 37 ], e.g., nucleotides, sugar phosphates, and organic acids. Williams and colleagues have collected and highlighted several practical pitfalls in the field of EV metabolomics research [ 38 ].…”