title: Quantitative determination of the loop diuretic bumetanide in urine and pharmaceuticals by high-performance liquid chromatography with amperometric detection.
abstract: A high-performance liquid chromatographic method with amperometric detection has been developed for the determination of the diuretic bumetanide using a microBondapak C18 column. The mobile phase consists of a 50:50 acetonitrile-water mixture containing 5mM KH2PO4-K2HPO4 (pH 4.0). The compound is monitored at +1350 mV with an amperometric detector equipped with a glassy carbon working electrode. A liquid-liquid or solid-liquid extraction is done prior to chromatographic analysis in order to avoid the interferences found in the urine matrix. The percentages of recovery obtained are 71%+/-1% for liquid-liquid extraction and 84.2%+/-0.7% for solid-liquid extraction. The method developed has a linear concentration range from 50 to 499 ng/mL with a reproducibility in terms of relative standard deviation of 1.73% and 3.85% for a concentration level of 70 ng/mL and 237 ng/mL, respectively, and a detection limit of 0.25 ng/mL (3:1 signal-to-noise ratio). The method is applied to the determination of bumetanide in pharmaceutical formulations and urine obtained from hypertensive patients and healthy volunteers after the ingestion of a therapeutic dose of Fordiuran (1 mg bumetanide).
authors.affiliation: Departamento de Química Analítica, Facultad de Ciencias, Universidad del País Vasco/EHU., Bilbao, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Legorburu
authors.forename: R M
authors.initials: RM
authors.lastname: Alonso
authors.forename: R M
authors.initials: RM
authors.lastname: Jiménez
authors.forename: E
authors.initials: E
authors.lastname: Ortiz
mesh_terms: D000328:Adult; D002034:Bumetanide / Q000032:analysis* / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004232:Diuretics / Q000032:analysis* / Q000652:urine; D004563:Electrochemistry; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results
chemical_list: D004232:Diuretics; D002034:Bumetanide