Temperature-programmed separation

The lack of an exact mathematical model to describe temperature programmed separations makes computer simulation for... 

Figure 1. Temperature-programmed separation of irradiation flavor isolates on a 20% Carbowax 20M column...

Air collected in a cryogenic trap under liquid argon trap warmed sample transferred onto a precooled GC column temperature programmed separated on the column and determined by FID, halogen specific detector, or GC/MS. 

Figure 8.20. A comparison of (a) isothermal and (b) temperature-programmed separation of ra-paraffins. Figure courtesy of McNair and Bonnelli, Basic Gas Chromatography, Varian, 1968.

Fig. 1.23 Temperature-programmed separation of chlorides of fission products [90], Conditions quartz column, length 75 cm, 8 mm i.d., packed with 0.25 mm quartz particles coated with NaCl heating rate 24.5 K min carrier gas nitrogen, 1cm3 min reagent CCI4, 100 mmHg.

Figure 20.6 shows a temperature programmed separation of a complex hydrocarbon mixture with stepwise linear temperature programming. The first 12 gaseous or light compounds are readily eluted d resolved at a low fixed (100°C) temperature for 5.5 min, while the others require higher temperatures. After 5.5 min, the temperature is linearly increased at 5°C/min for 20 min to 200°C, and then the temperamre is held at that value until the last two compoimds are eluted. 

Figure 5.1 (a) Separation of alcohols. Isothermal and temperature programmed separation at 100°C and 100-150°C at 15°Cmin respectively. Column 2mx in. Carbowax 20 carrier gas nitrogen, 30ml min injection 1 pi, neat 1 1 1 1 1 mixture detector FID. 

Relationships for predicting retention in temperature program separations using the linear-elution-strength model. 

Rg. 7-30 Separation of butylene isomers (isothermal and temperature programmed separation). 

FIGURE 5.24 High-speed temperature-programmed separation of a 20-component pesticide mixture without stop-flow operation (a), with a 2-s-wide stop-flow pulse to separate components 2 and 3 and (c), and with two stop-flow pulses to separate component pairs 2,3 and 10,11. Components are 1, a-BHC 2, P-BHC 3, y-BHC, 4, 8-BHC 5, heptachlor 6, aldrin 7, heptachlor epoxide 8, a-chlordane 9, y-chlordane 10, 4,4 -DDE 12, dield-rin 13, endrin 14, 4,4 -DDD 15, endosulfan II, 16, 4,4 -DDT 17, endrin aldehyde 18, metoxychlor 19, endosulfan sulfate 20, impurity 21 endrin ketone. 

Fig, 1, Isothermal and temperature programmed separation of a homologous series of n-alkanes column 20 ft x 1/16 in, 3% Apiezon-L on 100-120 mesh Varaport 30 flow rate 10 cm mim He, (a) Isothermal (b) Temperature programmed. 

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