Two of what I consider to be the best ones are summarized below. The organic fraction is evaporated to dryness and dissolved in methanol. The derivatives are determined using reverse phase high performance liquid chromatography HPLC with an ultra-violet detector. If the boiling point of a POHC of interest is less than 30 C, the POHC may break through the sorbent under the conditions of the sample collection procedure. The gas stream is cooled to 20 C by passage through a water-cooled condenser and volatile POHCs are collected on a pair of sorbent resin traps.
Liquid condensate is collected in an impinger placed between the two resin traps.
An alternative set of conditions for sample collection has been used. This method involves collecting a sample volume of 20 L or less at a reduced flow rate.