A sensitive and selective high-performance liquid chromatographic method for the determination of @entity52804 (I) in plasma is described. Compound I was extracted from plasma with @entity1044 using @entity69580 as aqueous phase support. The @entity1246 (II) formed after alkaline hydrolysis of I was derivatised with @entity20720 , chromatographed on a reversed-phase column, and quantified by fluorescence detection. The limit of quantification was 2.5 ng/ml (intra-assay R.S.D. 5%) using a 1-ml plasma sample. The inter-assay precision was 3-14% (R.S.D.) over the concentration range 2000-5 ng/ml, and the recovery from plasma was quantitative (99.3 +/- 2.9%). The accuracy of this method was established from the good agreement between the values obtained after the analysis of plasma samples by both this method and a gas chromatography--mass spectrometry method. The high-performance liquid chromatographic procedure was applied to the determination of (a) endogenous I in @entity1 plasma samples and (b) I in plasma following intravenous administration of this substance to a @entity235 . In twelve @entity1 subjects, endogenous concentrations of I of 8.3 +/- 2.3 ng/ml (gas chromatography--mass spectrometry method: 6.1 +/- 2.6 ng/ml) were found.

Determination of XXXX in plasma by high-performance liquid chromatography.

@entity1 :: ('9606', 'Species') :: ['human'] @entity1246 :: ('MESH:D005680', 'Chemical') :: ['gamma-aminobutyric acid'] @entity1044 :: ('MESH:D008752', 'Chemical') :: ['methylene chloride'] @entity235 :: ('9615', 'Species') :: ['dog'] @entity20720 :: ('MESH:D009764', 'Chemical') :: ['o-phthalaldehyde'] @entity52804 :: ('CHEBI:36592', 'Chemical') :: ['pyrrolidinone'] @entity69580 :: ('MESH:D007692', 'Chemical') :: ['kieselguhr']
@entity52804 :: (CHEBI:36592,Chemical) :: ['pyrrolidinone']
