GC038 Gas Sampling

These methods require the entire sample to be in the gas phase before the analysis. Mixtures of gases and liquids are problematic because in that case the analyst should convert all the sample to a gas, by heating the sample or to a liquid by increasing pressure. But this is not always possible.

There are two main methods two introduce gas samples. The first one is the use of gas­-tight syringes. This method is cheaper, more flexible and the most frequent method used. The other method is the use of gas-sampling valves, which is used frequently with packed columns; give better repeatability, requires less skill from the analyst and can be more easily automated.

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