Gas chromatographic retention indices for the N-methyl-N-substituted benzamides on capillary columns

Gas chromatographic retention indices (1) for series of 20 synthesized N-me thyl-N-substituted benzamides on DB-I, DB-5 and DB-WAX capillary columns is othermal at 170, 190 and 210 degreesC, and using temperature programmed gas chromatography (TPGC) have been determined within standard deviation of 0. 6 i.u. The isothermal data obtained on these columns and TPGC data are comp ared and a comparison of the retention indices, DeltaI and dI/dT values pre sented as linear regression equations with correlation coefficient greater than 0.9970 within standard deviation of 0.6 i.u. The best resolution of th e structural isomers is obtained using DB-1 capillary column.