TY - JOUR AU - Schreiber, W, E AB - Abstract This is a rapid (10 min per sample), highly sensitive procedure for quantifying urinary porphobilinogen (PBG). Interfering substances are removed by selectively adsorbing PBG onto an ion-exchange resin. After PBG is eluted with 0.5 mol/L formic acid, Ehrlich's reagent is added to produce the chromophore, which is then injected into a liquid chromatograph equipped with a diode-array detector. PBG is separated by a linear gradient (10% to 100%) of methanol in 10 mmol/L phosphate buffer, pH 3.0. Absorbance is monitored at 555 nm. Assay response varies linearly with PBG concentration over the range 0-110 mumol/L (0-25 mg/L). As little as 1.5 mumol/L (0.3 mg/L) can be detected. In prepared urine samples with known PBG concentrations, the within-run coefficient of variation (CV) ranged from 1.7% to 3.2%, the day-to-day CV from 3.5% to 6.1%. PBG concentrations in 24-h urine collected from 25 healthy subjects were all below the detection limit of the assay (less than 1.5 mumol/L). We used the new assay to measure PBG concentrations in the urine of two patients with latent porphyria. This method is more sensitive than spectrophotometric techniques currently used for measuring urinary PBG. This content is only available as a PDF. © 1989 The American Association for Clinical Chemistry, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) TI - Liquid-chromatographic assay of urinary porphobilinogen. JF - Clinical Chemistry DO - 10.1093/clinchem/35.3.471 DA - 1989-03-01 UR - https://www.deepdyve.com/lp/oxford-university-press/liquid-chromatographic-assay-of-urinary-porphobilinogen-cIIdf2eTxR SP - 471 EP - 475 VL - 35 IS - 3 DP - DeepDyve ER -