RAPID EXTRACTION METHOD OF QUANTITATING THE LACHRYMATORY FACTOR OF ONION USING GAS-CHROMATOGRAPHY

A rapid extraction method has been developed for the quantitation of ( Z,E)-propanethial S-oxide, the lachrymatory factor (LF), and other fla vor chemicals in onion (Allium cepa) using gas chromatography. This me thod involves crushing the onion and extracting the resulting juice wi th a solution of methylene chloride and an internal standard. The resu lting extract is concentrated and injected onto a gas chromatograph. T his method is shown to be simple, fast, and reproducible. Results show that onion juice contains 1-22 mu mol of the LF/mL.