I am developing a method for determining residual solvents (DMF, DMSO, methanol, dichloromethane and triethylamine) by GC/HS. I read several articles and thought I wouldn't have any problems. But I was wrong. I am using a DB-624 column 30m x 0.53mm x 3µm, equilibrium temperature at 100°C for 20 min x loop at 105°C x transfer line at 120°C, injector 210°C, detector 250°C; oven starts at 40°C. Basic...
To my surprise, my analysis was terrible, with very significant peaks near methanol and dichloromethane, and at other retention times. DMF d DMSO with very low signal also, when I don't add TEA to the mix, these interfering peaks don't come out. I carried out the test with reagents, I thought that was the problem, so I opened a USP ampoule of TEA and the interferers persist. Here in Brazil we don't have much support or published research on chromatographic problems. Help me please?
