Development of a rapid and accurate method for the determination of key compounds of pig odor.

Sampling of odor substances in the emissions from swine production facilities is still the limiting step for routine odor quantification. Solid sorption techniques based on cartridges were developed for three categories of substances (indoles, volatile fatty acids and methylthiol) and were standardized to a sampling time of 15 min. These cartridges also trap dust particles which transport odor substances. Quantification was performed by RP-HPLC or GC. Reliability criteria revealed excellent values for sensitivity (lower ppb level) and repeatability (R.S.D. < 10%), thus they are comparable to fiber solid-phase micro extraction sorption techniques. Parallel determinations in feces and air revealed high correlations (r = 0.99, P < 0.01), so that microbial processes during digestion determine odor quality and hence provide a possibility to reduce odor via feeding.