Determination of Residual Solvents in Azanavir Sulfate by Gas Chromatography-Flame Ionization Detector

A method to determine residual solvent in Azanavir sulfate by gas chromatography (GC) has been set up.And the sample preparation method using methanol:n-butanol (1:1, V/V) as the diluent was clarified particularly to eliminate the problem of interference in the determination.Test conditions of the flame ionization detector (FID) were as follows:temperature:240℃, temperature of injection port:200℃, split ratio:20:1, carrier gas:N₂, flow rate:1 mL/min.The initial temperature of the chromatographic column was 35℃, kept for 3 min, then increased to 70℃ at a heating rate of 2℃/min, and then increased to 220℃ at a heating rate of 20℃/min, and maintained for 2 min.The results showed that the interference problem of solvent mixture was solved, and the blank solution and Azanavir sulfate did not interfere the solvents to be tested, and all the residual solvent peaks were well separated, so the specificity was good.The LODs of ethanol, acetone, isopropanol, dichloromethane, methyl tert-butyl ether, n-heptane were 2.063, 0.575, 2.001, 4.379, 0.875, 0.504 μg/mL respectively.The linearities of above solvents were acceptable in the range of 5.16~751.23, 1.74~722.29, 5.00~754.03, 13.27~89.79, 2.65~750.12, 1.53~749.43 μg/mL (r=0.999 0~1.000 0) respectively.The RSD of the same homogenous sample was less than 5.0%, so the method was reproducible.The recoveries of all the results were in the range of 90%~110%, so the method was accurate.The method was suitable for testing residual solvents in Azanavir sulfate.