title: Extraction and preconcentration of residual solvents in pharmaceuticals using dynamic headspace-liquid phase microextraction and their determination by gas chromatography-flame ionization detection.
abstract: The present study describes a microextraction and determination method for analyzing residual solvents in pharmaceutical products using dynamic headspace-liquid phase microextraction technique followed by gas chromatography-flame ionization detection. In this method dimethyl sulfoxide (μL level) placed into a GC liner-shaped extraction vessel is used as a collection/extraction solvent. Then the liner is exposed to the headspace of a vial containing the sample solution. The effect of different parameters influencing the microextraction procedure including collection/extraction solvent type and its volume, ionic strength, extraction time, extraction temperature and concentration of NaOH solution used in dissolving the studied pharmaceuticals are investigated and optimized. Under the optimum extraction conditions, the method showed wide linear ranges between 0.5 and 5000 mg L-1. The other analytical parameters were obtained in the following ranges: enrichment factors 240-327, extraction recoveries 72-98% and limits of detection 0.1-0.8 mg L-1in solution and 0.6-3.2 μg g-1in solid. Relative standard deviations for the extraction of 100 mg L-1of each analyte were obtained in the ranges of 4-7 and 5-8% for intra-day (n = 6) and inter-day (n = 4) respectively. Finally the target analytes were determined in different samples such as erythromycin, azithromycin, cefalexin, amoxicillin and co-amoxiclav by the proposed method.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Mir Ali
authors.initials: MA
authors.lastname: Farajzadeh
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Hamideh
authors.initials: H
authors.lastname: Dehghani
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Adeleh
authors.initials: A
authors.lastname: Yadeghari
authors.affiliation: Department of Chemistry, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Eastern Azarbaijan, Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Khoshmaram
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D004340:Drug Contamination; D005410:Flame Ionization / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D009994:Osmolar Concentration; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D012997:Solvents / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D004364:Pharmaceutical Preparations; D012997:Solvents; D012965:Sodium Chloride
keywords: dynamic headspace-liquid phase microextraction; gas chromatography; pharmaceuticals; residual solvents