Gas chromatographic--mass fragmentographic determination of homopantothenic acid in plasma.

A gas chromatographic--mass fragmentographic method was developed for the determination of homopantothenic acid in plasma. Acidified plasma was deproteinized by extraction with chloroform and subsequently the aqueous layer was extracted with ethyl acetate. The organic layer containing homopantothenic acid was reduced to dryness, and the resulting residue was redissolved in N,O-bis(trimethylsilyl)trifluoroacetamide--pyridine solution to allow trimethylsilylation. Aliquots of this solution were injected into the gas chromatograph--mass spectrometer and analyzed by the selected ion monitoring method using L-ascorbic acid as an internal standard. The detection limit for homopantothenic acid was 5 ng/ml of plasma. A precise and sensitive assay for the determination of homopantothenic acid in plasma was established.