Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) Colorimetry (C) (1) Enzyme-Linked Immunosorbent Assay (ELISA) (2) Enzyme Immunoassay (EIA) (1) Gas Chromatography/Mass Spectrometry (GC/MS) (3) Headspace Gas Chromatography (GC) (2) (-) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (1) Sample Type Blood (2) Serum or Plasma (2) (-) Urine (1) Test Area Therapeutics (1) Test Category Antiparkinsons (1) Test Sub-Category Anticholinergics (1) Test Test Name 4680U Trihexyphenidyl, Urine