title: [Solvent extraction-flow injection analysis for determination of trimethoprim in compound preparations].
abstract: Trimethoprim (TMP) in four pharmaceutical preparations (compound sulfamethoxazol tablets, compound tetracycline tablets, compound trimethoprim and sulfamethoxazol tablets; and compound berberine injection) is determined by solvent extraction-flow injection spectrophotometry. It can be extracted into chloroform directly, and the absorbance at a wavelength of 280 nm of the organic phase is measured after phase separation. The manifold comprises two streams. The sample is injected into a 0.2 mol/L NaOH carrier stream, and extracted with chloroform in a 200-cm coil (ID 0.7 mm) after a 50 cm reaction tube (ID 1.0 mm). Calibration graph is linear in the range of 25-150 micrograms/ml. The average recovery is 101.4% with a relative standard deviation of 1.1%. The proposed system permits the analysis of about 50 samples per hour. Precise results in agreement with those obtained with official methods are achieved.
authors.affiliation: Hubei Provincial Institute for Drug Control, Wuhan.
authors.forename: W Z
authors.initials: WZ
authors.lastname: Liu
authors.forename: J Q
authors.initials: JQ
authors.lastname: Gao
mesh_terms: D004338:Drug Combinations; D017022:Flow Injection Analysis; D013607:Tablets / Q000032:analysis; D014295:Trimethoprim / Q000032:analysis*
chemical_list: D004338:Drug Combinations; D013607:Tablets; D014295:Trimethoprim