title: Quality control Fourier transform infrared determination of diazepam in pharmaceuticals.
abstract: A quality control procedure has been developed for the determination of diazepam in pharmaceuticals using Fourier transform infrared (FTIR) spectroscopy. The method involves the off-line extraction of diazepam with chloroform by sonication and direct determination in the extracts through peak area measurement in the interval between 1672 and 1682 cm(-1) using a baseline correction defined between 1850 and 1524 cm(-1). For standardization it was used an external calibration line established from standard solutions of diazepam in chloroform. The method provides a limit of detection of 0.04 mg per tablet (n=5), a relative standard deviation (R.S.D.) of 0.5% for 5 independent measurements of a standard solution at a concentration level of 0.76 mg g(-1) and a sampling frequency of the whole procedure of 4 h(-1), being required only 45 s for the measurement step. Results obtained by FTIR agree with those obtained by a reference methodology based on ultraviolet spectrometry and thus the developed procedure offers a good alternative for the determination of diazepam in pharmaceuticals.
authors.affiliation: Department of Analytical Chemistry, University of Valencia, 50 Dr. Moliner Street, 46100 Burjassot, Valencia, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Moros
authors.forename: Salvador
authors.initials: S
authors.lastname: Garrigues
authors.forename: Miguel
authors.initials: M
authors.lastname: de la Guardia
mesh_terms: D014151:Anti-Anxiety Agents / Q000032:analysis*; D002138:Calibration; D003975:Diazepam / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000032:analysis*; D011786:Quality Control; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation / Q000379:methods*; D013607:Tablets
chemical_list: D014151:Anti-Anxiety Agents; D004364:Pharmaceutical Preparations; D013607:Tablets; D003975:Diazepam