Introduction to Modulation Technology

The thermal sweeper is a commercial product licensed to Zoex Corporation, Lincoln, NA, USA (16). The sweeper incorporates a slotted heater (operated at about 100 °C above the oven temperature) which passes over the capillary column (normally an intermediate thicker film column is used in this region as an accumulator zone). Eigure 4.3 is a schematic diagram of how the instrumental arrangement may be considered. The greater temperature of the rotating sweeper forces the solute which has been retained in the phase in the accumulator section to be volatilized out of the phase into the carrier gas stream, and then bunched up and brought forward 

3 MODES OF THE LMCS USING COUPLED SEPARATION COLUMNS 

Once solute has been focused in space within the cryotrap, they are subsequently ejected out of the cold region (we can refer to this as being like a re-injection into the 

Accepting that the cryofocussing/remobilization process is both effective in the collection of discrete sections of the effluent from column 1, and very rapid in reinjection to column 2, we can now propose a number of ways of using the LMCS device in multidimensional gas chromatography modes. 

It is again clear that the two benefits of increased sensitivity and better resolution are both achieved, where these arise from zone compression and phase selectivity, respectively. However, since this mode of analysis is relatively new, it has yet to be tested for a wide range of applications such studies will be required to fully demonstrate its general utility. It is unclear whether this operational mode of selective MDGC constitutes a mode which is consistent with the definition of comprehensive 

Each of these is a separate second-dimension chromatogram of slices of the first dimension 

---