Capillary electrophoresis as a clinical tool. Determination of organic anions in normal and uremic serum using photodiode-array detection.

We report the use of free solution capillary electrophoresis to identify and quantify low-molecular-mass compounds found in normal and uremic serum as well as in hemodialysate fluid. The method reported provides a multicomponent analysis, allowing a single-step screening for more than 19 metabolites in less than 16 min. Serum samples from healthy individuals and from patients who have been diagnosed with chronic renal failure are analyzed using a borate buffer system at pH 9.

High-performance liquid chromatographic separation of biogenic polyamines using 2-(1-pyrenyl)ethyl chloroformate as a new fluorogenic derivatizing reagent.

The application of a new fluorogenic pre-column derivatizing reagent, 2-(1-pyrenyl)ethyl chloroformate (PEOC), is reported for the separation and detection of biogenic polyamines using column liquid chromatography. The development of the method included the optimization of excitation and emission wavelengths, efficient gradient programming, derivatization temperature, time, and pH. Minimum detection limits, linear ranges, reproducibility, and recovery from analyzed samples were determined.

Determination of guanidino compounds by anion-exchange chromatography and amperometric detection.

Guanidino compounds were separated and determined by anion-exchange chromatography and electrochemical detection using a basic aqueous eluent and a nickel working electrode. It was found necessary to use a sample clean-up procedure prior to chromatographic analysis of uremic dialysate and serum samples. The effect of eluent hydroxide concentration on the retention of guanidino compounds was studied.

Liquid-chromatographic study of fluorescent compounds in hemodialysate solutions.

We have separated and identified three endogenous, naturally fluorescent substances in uremic hemodialysate by using reversed-phase liquid chromatography with fluorescence detection. Co-chromatography with authentic standards, monitoring peak shifts after enzymic treatment, and spectrofluorescence measurements were used to confirm the identity of indican, tryptophan, and indole-3-acetic acid. Concentrations of indican were about 1.