title: The Riker method for determining formaldehyde in the presence of methenamine.
mesh_terms: D003080:Cold Temperature; D003124:Colorimetry; D005557:Formaldehyde / Q000652:urine*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008709:Methenamine / Q000378:metabolism / Q000652:urine*; D008722:Methods; D009994:Osmolar Concentration; D010070:Oxalates; D010659:Phenylhydrazines; D013048:Specimen Handling; D013997:Time Factors
chemical_list: D010070:Oxalates; D010659:Phenylhydrazines; D005557:Formaldehyde; D008709:Methenamine