Determination of residual solvents in propyphenazone by headspace GC

Objective:To establish a method for determining residual solvents such as methanol,ethanol and acetone in propy-phenazone by headspace gas chromatography.Methods:The GC was equipped with a headspace injector and a flame-ionization dete(?) tor.A 0. 53mm×30m, DB-624 chromatographic column(coated with 6% cyanopropylphenyl-94% dimethyl polysiloxane) was adopted. The carrier gas was nitrogen.The assay of residual solvents were calculated according to the external standard method.Results:Only ethanol was found in the sample of propyphenazone.The standard curves were linear over the ranges of 0.10-164.96μg/mL(r= 0.9999) for ethanol,0.10-163. 36μg/mL(r=1.000 0) for acetone and 0.21-164.72μg/mL(r=0.999 9) for methanol. The limits of quantitation were 0. 3μg/mL for methanol and ethanol, 0. 1μg/mL for acetone.The average recoveries were 101. 0% ( RSD = 4.8% ,n=6)for methanol,99.89%(RSD=4.4%,n=6) for ethanol,99.85%(RSD=3.4%,n=6) for acetone.Conclusion:This method appeared to be sensitive,accurate,repeatable and easy to operate and was suitable for determining residual solvents of propyphenazone.