title: Colorimetric assay of 2,2-bis(4-chlorophenyl)acetic acid (DDA) in urine.
abstract: 2,2-Bis(4-chlorophenyl) acetic acid (DDA) was extracted from acidified urine at pH 2 by benzene. It was complexed by partitioning with crystal violet in acetic to yield a blue color which was quantitated at 610 nm. Its identity was confirmed by paper chromatographic separation. The DDA excretion in nine subjects ranged from 0.024 to 0.130 microgram/ml with a mean of 0.065 while that determined by gas chromatography ranged from 0.038 to 0.120 with a mean of 0.069.
mesh_terms: D000328:Adult; D002854:Chromatography, Paper; D003124:Colorimetry / Q000379:methods; D003634:DDT / Q000031:analogs & derivatives* / Q000652:urine; D006801:Humans; D008297:Male; D013053:Spectrophotometry
chemical_list: C000849:bis(p-chlorophenyl)acetic acid; D003634:DDT