title: Direct spectorphotometric assay of quaternary ammonium compounds using bromthymol blue.
abstract: Benzalkonium chloride, benzethonium chloride, and chlorhexidine gluconate were assayed quantitatively by a direct spectrophotometric method with bromthymol blue buffered at pH 7.5. The method shows good results at concentrations of 0--300 microgram/ml and in the presence of epinephrine bitartrate, phenylephrine hydrochloride, pilocarpine hydrochloride, and polyvinyl alcohol.
mesh_terms: D001548:Benzalkonium Compounds / Q000032:analysis; D001558:Benzethonium / Q000032:analysis; D001979:Bromthymol Blue; D002710:Chlorhexidine / Q000032:analysis; D008722:Methods; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D013053:Spectrophotometry; D013943:Thymol / Q000031:analogs & derivatives*
chemical_list: D001548:Benzalkonium Compounds; D000644:Quaternary Ammonium Compounds; D001558:Benzethonium; D013943:Thymol; D002710:Chlorhexidine; D001979:Bromthymol Blue