Development of an assay for the extraction and quantification of nine 5-n-alkyl-5-ethyl barbituric acids in various rat tissues

Methods were developed to quantify a series of nine homologous 5-n-alkyl-5- ethyl barbituric acids in 15 rat tissues. Tissue homogenates were spiked wi th one of four multicomponent mixtures (methyl to n-propyl, n-propyl to n-p entyl, n-pentyl to n-heptyl and n-pentyl to n-nonyl). Liquid-liquid extract ion was used to extract the homologues from the rat tissues. Reverse phase HPLC with UV detection at 214 nm was used to separate and quantify the indi vidual barbiturates. The limit of detection for each respective homologue w as 1 mu g g(-1) except skin and bone (2 mu g g(-1)). The methodology develo ped reduced a potential 135 individual assays to a more manageable 16. (C) 1999 Elsevier Science B.V. All rights reserved.