Background: Cobalamin deficiency and peripheral neuropathy (PN) are commonly seen in HIV-infected adults. The level of urine methylmalonic acid (UMMA), a reliable indicator of tissue cobalamin status, was determined in HIV infected subjects with and without PN to establish this association. Methods: One hundred and ninety-eight (198) consenting HIV infected subjects with and without PN were rec...

Two novel analytical methodologies using capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) were developed and compared for the determination of benzyldimethyldodecylammonium bromide (BAB) in commercial compound chemical disinfectants. The LC analysis was performed with a Kromasil C18 (200 mm x 4.6 mm, 5 microm) column and a mobile phase of A:B = 80:20 (A: acetonit...

To validate azotemic markers as an index for intradialytic changes in solute concentration, we compared eight solutes (pseudouridine, xanthine, hypoxanthine, peak 4, peak 5, p-hydroxyhippuric acid, indoxyl sulfate, and hippuric acid) with five classical azotemic markers (urea, creatinine, uric acid, phosphate, and potassium). We determined concentrations by reversed-phase HPLC coupled to ultrav...

BACKGROUND Benzophenone-3 (BZ-3) is a common ultraviolet (UV) absorbing compound in sunscreens. It is the most bioavailable species of all UV-absorbing compounds after topical application and can be found in plasma and urine. OBJECTIVES The aim of this study was to develop a reverse-phase high performance liquid chromatography (HPLC) method for determining the amounts BZ-3 and its metabolite ...

Purpose: To develop a sensitive and rapid reverse phase high performance liquid chromatography (HPLC) method for the measurement of the levels of zidovudine (ZVD) and nevirapine (NVP) in human plasma. Methods: Standard stock solutions for HPLC analysis were prepared by dissolving ZVD and NVP in methanol. In the HPLC measurement, sample detection was carried out at 246 nm using an ultraviolet (U...

Organic anions accumulated in blood serum of patients with chronic renal failure were separated by a novel technique: closed-system capillary zone electrophoresis (CZE) in a pH6 carrier-electrolyte system. Hippuric acid (HA), p-hydroxyhippuric acid, and uric acid were identified by their co-elution with standards prepared in ultrafiltered normal serum and by comparison with the corresponding ul...

In this HPLC-diode-array detection method for toxicological drug screening, a mixed-mode solid-phase extraction procedure is optimized for isolation of a broad range of drugs from serum and urine. Basic, neutral, and weakly acidic drugs are uniformly recovered. The extract from the solid-phase cartridge is readily injected to a reversed-phase HPLC column for separation by gradient elution. Unkn...