Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10532693 | Analytical Biochemistry | 2013 | 7 Pages |
Abstract
Branched-chain keto acids (BCKAs) are associated with increased susceptibility to several degenerative diseases. However, BCKA concentrations in tissues or the amounts of tissue available are frequently at the limit of detection for standard plasma methods. To accurately and quickly determine tissue BCKAs, we have developed a sensitive ultra fast liquid chromatography-mass spectrometry (UFLC-MS) method. BCKAs from deproteinized tissue extractions were o-phenylenediamine (OPD) derivatized, ethyl acetate extracted, lyophilized in a vacuum centrifuge, and reconstituted in 200Â mM ammonium acetate. Samples were injected onto a Shimadzu UFLC system coupled to an AB-Sciex 5600 Triple TOF mass spectrometer instrument that detected masses of the OPD BCKA products using a multiple reaction monitoring method. An OPD-derivatized 13C-labeled keto acid was used as an internal standard. Application of the method for C57BL/6J (wild-type) and PP2Cm knockout mouse tissues, including kidney, adipose tissue, liver, gastrocnemius, and hypothalamus, is shown. The lowest tissue concentration measured by this method was 20Â nM, with the standard curve covering a wide range (7.8-32,000Â nM). Liquid chromatography-mass spectrometry run times for this assay were less than 5Â min, facilitating high throughput, and the OPD derivatives were found to be stable over several days.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Kristine C. Olson, Gang Chen, Christopher J. Lynch,