Ballistic temperature programming

FIGURE 3.63 Types of temperature programming (a) ballistic temperature programming (b) linear temperature programming and (c) multilinear temperature programming. 

Ballistic or natural temperature-programming is available on isothermal controllers and is obtained when the isothermal set-point is suddenly changed to a higher isothermal temperature. 

Figure 7. GC analysis of a synthetic mixture of diacylglycerols as their TBDMS ethers on a 25 m x 0.25 mm i.d. capillary column, coated with RSL-300 (methyl 50% phenylsiloxane) polarizable stationary phase. Tentative peak identification as given in the figure. Temperature programming was from 40-290 °C, ballistic 290 °C, isothermal for 0.5 min 290-330 C, I0°C/min 330-360 °C, 1 C/min. Dioleoyl-glycerol retained 21.23 min. Carrier gas, hydrogen at 1 bar head pressure. Manual on-column injection with fused-silica needle at 40 °C. (Reproduced from Ref. 188 with permission).

GC/NICI-MS Analysis. Residue fractions were analyzed by methane GC/ NICI-MS before and after silver ion derivatization. A fused-silica SE54 capillary GC column (J W Scientific, 30 m X 0.25 mm) was used for separations. The injector temperature was 270 °C, and the oven was held at 40 °C for 2 min, ramped ballistically to 60 °C, and programmed for 60-270 °C at 4 °C/min. The final hold was at 270 °C. Helium carrier gas was used at a flow rate of 22 cm/s. A Finnigan 4023-INCOS GC-MS-DS equipped with a PPINICI source was used with the following conditions emission current, 30 mA electron multiplier voltage, 1000 V electron energy, 70 V manifold, 80 °C source, 200 °C and 0.45 torr... 

Figure 9. Total ion chromatogram for Boscan crude oil obtained by computer summation of ions in the mass range 550—850. Analyses were performed on a 25 m x 0.3 mm i.d. OV-I coated (0.17//m) flexible silica capillary (Hewlett-Packard) using helium carrier gas at a linear flow rate of 50 cm/s. Following on-column injection of ca. 2.5 fig of porpyrins as their (TBDMSO)2Si(IV) derivatives (e.g. see inset, desoxophylloerythroacetioporphyrin derivative, major component of starred peak), the GC oven temperature was programmed ballistically from ambient to 150 °C, then from 150-290 °C at 3°C/min. The retention time scale has been converted to Kovats retention indices by computer interpolation from co-chromatographed n-alkanes..

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