Title : Qualitative analysis of the six benzodiazepines by gas chromatography-mass spectrometry and high performance liquid chromatography.
Background: Gas chromatography – mass spectrometry and high performance liquid chromatography are commonly used methods for determination of benzodiazepines. GC-MS is a specific method and is used for its sensitive and accurate determination. HPLC is a simple and quick method and it is used of its rapid analysis.
Objective:The aim of this study is to identify six different benzodiazepines – diazepam, medazepam, bromazepam, clonazepam, alprazolam and lorazepam in mixture by gas chromatography – mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC).
Methods: The analysis of six benzodiazepines (diazepam, medazepam, bromazepam, clonazepam, alprazolam and lorazepam) was done using SHIMADZU GC-MS-QP2010 Ultra chromatography system with Rxi – 5ms (Restek Corporation) fused silica capillary column (30m x 0,25 mm, 0,25 µm film coating). The second method was carried out on Waters Alliance 2695 separation module system equipped with Waters 996 DAD detector and ACE C18 (250 x 4,6 mm, 5 μm) column. The mobile phase consisted of 0,1 % trifluoracetic acid and acetonitrile.
Results: Both methods were successfully used for qualitative analysis of six benzodiazepines. The retention time by GC-MS of diazepam, medazepam, bromazepam, clonazepam, alprazolam, lorazepam was found to be of 9.956, 8.923, 11.108, 12.610, 13.396 and 9.801 min, respectively. The retention time by HPLC of diazepam, medazepam, bromazepam, clonazepam, alprazolam, lorazepam was found to be 14.625, 13.791, 11.456, 15.024, 14.398 and 14.861 min., respectively.
Conclusion: Both methods are simple, accurate, sensitive and suitable for benzodiazepines determination in pharmaceutical dosage forms and could be used in routine analysis with forensic samples.