Figure 1: Representative GC chromatogram of residual solvents. 1: methanol; 2: ethanol; 3: ether; 4: acetone; 5: isopropanol; 6: acetonitrile; 7: methylene chloride; 8: t-butanol; 9: methyl ethyl ketone; 10: ethylacetate; 11: tetrahydrofuran (THF); 12: chloroform; 13: trimethylamine; 14: heptane; 15: butanol: 16: 1,4-dioxane; 17: toluene; 18: dimethyl sulfoxide (DMSO).