ATMOSPHERIC MONITORING OF VOLATILE ORGANIC-COMPOUNDS USING PROGRAMMED-TEMPERATURE VAPORIZATION INJECTION

A method has been developed for the automated determination of C-5-C-1 0 and C-2-C-6 volatile organic compounds in urban and rural air, using programmed temperature vaporization injection from a sorbent tube tra p. A single activated charcoal sorbent tube was repeatedly used to col lect samples of air with trapped VOCs being subsequently. desorbed ont o either a wide bore dimethyl polysiloxane (C-5-C-10) or porous layer open tubular (C-2-C-6) gas chromatography column without use of interm ediate cryogenic refocussing, The high flow rates of helium used durin g the analysis resulted in the sample tube being cleaned and ready to reuse following the analytical separation, Examples of analysis of aro matic VOCs in urban air, and biogenic emissions in rural air, collecte d in a Sitka Spruce forest are presented, Using this method it is poss ible to quasi-continuously monitor concentrations of VOCs in locations where high sensitivity in situ analysis is required, but where cryoge nic coolants may not be readily available or desirable.