Multi-Residue Analysis of Four Volatile Organic Solvents in Omeprazole Materials Using Capillary Gas Chromatography

Abstract

A new multi-residue analytical method was developed for the simultaneous determination of four volatile organic solvent residues (acetonitrile, methanol, acetone and methylene chloride) in omeprazole materials by capillary gas chromatography with n-hexane as an internal standard. Direct injection and fast temperature-programmed mode were employed in this work and a PEG-20M flexible fused quartz capillary column (30 m × 0.25 mm × 0.33 μm) was used as the analytical column with FID detection. The influence of several important parameters on separation and detection of the four target analytes were carefully investigated. Under the optimum condition, good linearity were obtained in a range of 0.0007-0.9 mg/mL for all with the correlation coefficients (r²) > 0.999. The average recoveries of all target analytes from omeprazole materials at three spiking levels were ranged from 94.5-107.9 % with the relative standard deviations less than 4.2 % (n = 5). The proposed method has the advantage of simplicity of operation, being fast and high recovery and is therefore an alternative tool to the existing methods for analyzing the solvent residuals in omeprazole products.