Recent advances in high-performance liquid chromatography/mass spectrometry and high-performance liquid chromatography/tandem mass spectrometry: detection of cyclosporine and metabolites in kidney and liver tissue.

Recent advances in both ionization methods and mass spectrometers have resulted in powerful new techniques for the study of drug metabolism and disposition. The interest in high-performance liquid chromatography/mass spectrometry (HPLC/MS) is the result of the lack of a sensitive universal detector for HPLC. Although it is not the ideal detector, HPLC/MS has become a reliable technique for xenobiotic analysis.

Determination of urinary succinylacetone by capillary gas chromatography.

The average analytical recovery of succinylacetone added to urine and separated by capillary gas chromatography was 69% for solvent extraction and 72% for anion exchange separation. Treating succinylacetone with hydroxylamine hydrochloride at a pH of less than 5 caused formation of a derivative separated by capillary gas chromatography into two isomers: 3-methyl-5- isoxazole propionate and 5-methyl-3- isoxazole propionate as their trimethylsilyl derivatives (molecular weight 227). In a pH greater than or equal to 5, succinylacetone dioxime was formed and separated into 3 isomers as their trimethylsilyl derivatives (molecular weight 404).

Capillary gas chromatographic separation of urinary organic acids. Retention indices of 101 urinary acids on a 5% phenylmethyl silicone capillary column.

Gas chromatographic retention indices (methylene units) are reported for 101 urinary organic acids as their trimethylsilyl and oximated trimethylsilyl derivatives on a 5% phenylmethyl silicone fused silica capillary column. Using anion exchange chromatography, organic acids were extracted from urines of five healthy individuals, seven patients with neuroblastoma, and nine patients with inherited organic acidurias. Separation of the various acids was achieved by capillary gas chromatography and identification was done by mass spectrometry using a computerized library search program.