SOLID-PHASE MICROEXTRACTION ANALYSIS OF STATIC-AIR EMISSIONS OF AMMONIA, METHYLAMINE, AND PUTRESCINE FROM A LURE FOR THE MEXICAN FRUIT-FLY (ANASTREPHA LUDENS)

A method was developed to analyze ammonia, methylamine, and putrescine emanating from a lure for the Mexican fruit fly (Anastrepha ludens). Lures were put into closed glass vessels containing 2% phosphoric acid to trap the basic volatiles. The phosphoric acid solution was then ma de basic, and solid-phase microextraction (SPME) was used to sample th e dissolved chemicals and load them without solvent onto a thick-film gas chromatography column. Calculated emissions from the lures at 35 d egrees C were 234-373 mu g/h for ammonia, 25.8-61.3 mu g/h for methyla mine, and 15.0-19.4 ng/h for putrescine during the first 48 h after op ening the tubes. 1-Pyrroline, a chemical not present in the lures by d esign, emanated at similar to 20 ng/h. Flame thermionic detection aide d analysis of putrescine and 1-pyrroline. Experiments with standards i ndicated that determination errors of +/- 50% could be expected due to inherent problems associated with the analytical methods.