title: First practical colorimetric assay of lithium in serum.
abstract: We report a colorimetric method for determining lithium in blood serum without sample pretreatment or solvent-extraction steps. The method is based on a novel chromogenic ionophore that exhibits exceptionally high selectivity (much greater than 4000:1) for lithium over sodium. The standard curve for the method is linear up to 3.5 mmol/L and exceeds the therapeutic range for lithium. The results for 57 patients' samples correlated well with results obtained with an Instrumentation Laboratory flame photometer (r = 0.97).
authors.affiliation: Miles Incorporated, Tarrytown, NY 10591.
authors.forename: E
authors.initials: E
authors.lastname: Chapoteau
authors.forename: B P
authors.initials: BP
authors.lastname: Czech
authors.forename: W
authors.initials: W
authors.lastname: Zazulak
authors.forename: A
authors.initials: A
authors.lastname: Kumar
mesh_terms: D003124:Colorimetry / Q000379:methods*; D005026:Ethylene Glycols / Q000737:chemistry; D006801:Humans; D007476:Ionophores / Q000737:chemistry; D008094:Lithium / Q000097:blood*; D015203:Reproducibility of Results; D013501:Surface-Active Agents
chemical_list: D005026:Ethylene Glycols; D007476:Ionophores; D013501:Surface-Active Agents; C048214:diethylene glycol monomethyl ether; D008094:Lithium