Capillary Columns

Typical carrier gas flow rates for 0.3 mm i.d. wall-coated open-tubular (WCOT) columns are less than 2 mL min"1. The vapour from 1 |L solvent occupies approximately 0.5 mL at 250°C. If the injector volume is 1.0 mL and flow of one injector volume of carrier gas sweeps all the vapour on to the column (no diffusion of sample with carrier gas), transfer time is >30 s - considerably more than the 5 s peak widths typically encountered in capillary GC. In reality, sample concentration in the carrier gas decreases exponentially because carrier gas diffuses into the sample vapour cloud; this adds a tail to the band widths given above.

There is clearly a need for a different method of injection or a means of narrowing the band-width.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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