Purge condensate analysis

Equipment for hydride reactions must be scrupulously dry before use. This includes valve bonnets, outlets to gages, vent lines, and traps. The atmosphere should contain less than 1% oxygen by analysis. Purging with inert gas (carbon dioxide is not inert ) is excellent. The hydride is added through an entrance lock for bags or by a hopper whose connecting valve and pipe can be purged. Reactors should be heated or cooled with oil or Dowtherm, even for condensers. 

Purge-and-Trap Sampling Purge and trap sampling is a family of methods that are used to capture the headspace above a condensed phase for subsequent analysis, most often for complex mixtures, environmental samples, etc. The headspace is the vapor space that develops above any condensed (solid or liquid) phase. Thermodynamics assures us that the concentration of a particular analyte found in the headspace will be different than that found in the condensed phase, but often the relationship is predictable. The value in the method comes from the simplicity sample preparation is usually far simpler than the cleanup that is typically required for many complex mixtures. Purge and trap methods fall into two general categories ... 

Madden, A.T. and Lehan, H.J. (1991) The effects of condensate traps on polar compounds in purge and trap analysis. Pittsburgh Conference. 

Figure 4.10 Purge and trap GC-MS chromatogram for the analysis of a condensate from a block heating power station run on gas from landfill sites.

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