Ammonium 5-bromo-7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate: a new fluorogenic reagent for the determination of aminothiols by HPLC.

High performance liquid chromatography method for rapid and accurate determination of homocysteine in plasma and serum.

Determination of homocysteine in plasma or serum for evaluation of cobalamin and folate deficiency is becoming an important diagnostic procedure. Accurate, rapid and low cost methods for measuring homocysteine are therefore required. We have improved an HPLC method and made it suitable for clinical application. The more important changes are the addition of an internal standard, mercaptopropion...

Measurement of homocysteine and other aminothiols in plasma: advantages of using tris(2-carboxyethyl)phosphine as reductant compared with tri-n-butylphosphine.

BACKGROUND Aminothiols have been implicated in the pathogenesis of arteriosclerosis, and reliable methods are needed to determine their concentrations in body fluids. We present a comparison of two analytical methods and focus on the reduction of low-molecular weight and protein-mixed disulfides of homocysteine, cysteine, cysteinyl-glycine, and glutathione. METHODS The plasma total aminothiol...

Enzyme-based diagnosis of classical late infantile neuronal ceroid lipofuscinosis: comparison of tripeptidyl peptidase I and pepstatin-insensitive protease assays.

References 1. White AC, Thannickal VJ, Fanburg BL. Glutathione deficiency in human disease. J Nutr Biochem 1994;5:218–26. 2. Ubbink JB, Vermaak WJH, Bissbort S. Rapid high-performance liquid chromatographic assay for total homocysteine levels in human serum. J Chromatogr B 1991;565:441–6. 3. Araki A, Sako Y. Determination of free and total homocysteine in human plasma by high performance liquid...

Determination of total homocysteine in human plasma by isocratic high-performance liquid chromatography.

A simple, sensitive and precise isocratic HPLC method for the determination of total homocysteine in human plasma is described. The thiol compounds were liberated from plasma proteins by reduction with tri-n-butylphosphine and derivatized with a thiol-specific fluorogenic marker, 7-fluoro-benzo-2-oxa-1,3-diazole-4-sulphonate. The derivatives were separated isocratically within 7 min by reversed...

7-chloro-4-nitrobenzo-2-oxa-1,3-diazole: a new fluorigenic reagent for amino acids and other amines.