title: Obviating interferences in the assay of urinary oxalate.
abstract: Evaluation of the Sigma Kit for determination of urinary oxalate highlighted two major limitations of which users must be aware: the pH of urine samples before extraction is critical, and ascorbic acid interferes positively. I give details, and describe simple modifications to the manufacturer's protocol that overcome these problems.
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010070:Oxalates / Q000652:urine*; D019815:Oxalic Acid
chemical_list: D010070:Oxalates; D019815:Oxalic Acid; D001205:Ascorbic Acid