EVALUATION OF THERMAL DESORPTION FOR THE MEASUREMENT OF ARTIFICIAL SWINE ODORANTS IN THE VAPOR PHASE

Abstract

Quantification of odorants from animal production facilities is difficult. The current technique is to collect airsamples in Tedlar bags and quantify odor using a trained olfactory panel. In this approach, relative differences betweensamples can be determined, but further quantification of odorants is limited. An alternative approach is to quantify odorantsin air emissions using sorbent tubes. A sorbent tube is a glass tube packed with a specific adsorbent material (Tenax TA,Carboxen 1000, Carbosieve SIII, etc.) and has been used to collect volatiles and quantify emissions from various industrialsources. Each adsorbent has a limited range of chemical selectivity. Limited applications of sorbent tubes with single or dualadsorbents have been used to measure odorant emissions from animal production facilities.<br><br>In this study, tripacked sorbent tubes and Tedlar bags were compared in characterizing 19 major odorants found inartificial swine odor. The sorbent tubes were packed with Tenax TA, Carboxen 1000, and Carbosieve SIII. The artificial swineodor was directly desorbed onto the tripacked sorbent tube. For comparison, a 10L Tedlar bag was filled with nitrogen gasand artificial swine odor. The Tedlar bag was then desorbed onto the tripacked sorbent tube. The sorbent tube was thenthermally desorbed into a gas chromatography (GC) system with a flame ionization detector (FID) for quantification. Thetripacked sorbent tube demonstrated recoveries greater than 74% and detection limits less than 0.4 ng for all 19 odorants.Thus, a tripacked sorbent tube may provide an analytical method to measure low concentrations of major odorants foundin air emissions from swine production facilities. Tedlar bags showed limited recoveries of some odorants, less than 12% forindole and skatole. In addition, Tedlar bags immediately sampled after three flushings with nitrogen emitted 3.50 ng L1 hr1of acetic acid (~35% above background levels) and 2.13 ng L1 hr1 phenol (~27% above background levels). These resultssuggest that air samples collected in Tedlar bags may bias olfactory analysis.