1992 Volume 27 Issue 1 Pages 45-57
Florisil and silica gel were evaluated as trapping adsorbents for 137 kinds of airborne pesticides by investigating their retention efficiencies (recovery when a pesticide in solution was placed into the trap through which air was passed) and sampling efficiency (recovery when a vaporized pesticide passed with air through the trap). The both adsorbents showed the same characteristics and were useful for trapping most of the airborne pesticides. The sampling efficiencies and the retention efficiencies were approximate for Florisil, but tne formers were high values than the latters about the several pesticides for silica gel.
Among the pesticides investigated, captafol, DNBP, and pival were not well recovered with acetone from the adsorbents. CDEC, DBCP, disulfoton, ethiofencarb, formothion, methyltrithion, phorate, propaphos and trithion were not quantitatively sampled onto the sampling mediums due to breakthrough, oxidation and other decompositions. BRP, Chloroneb, ciodrin, CMDP, CNA, DCPA, HCH, heptachlor, lenacil, MCC, MEP, MPP, PCNB, TPN, phosphamidon, triflumizole showed somewhat lower sampling efficiencies due to large sampling volume and/or sampling temperature. However, these pesticides could be well sampled and analyzed by selecting a suitable sampling volume or period. The other 105 pesticides could be well collected onto the trap with 2-19 m3 of air sample.
he proposed method resulted in several advantages as follows:
1) The adsorbents were easily and inexpensively obtained from the manufactures.
2) They were purified by simple decantation with acetone.
3) No special wares, equipments and techniques were required for sampling and analysing the pesticides.
4) Necessary sampling volume was easily attained at 13 l/ min of sampling rate.
5) The most pesticides were effectively sampled into the adsorbents and well recovered from the adsorbents with acetone without any decomposition except for several pesticides.
