Selective Purge-and-Trap Method for the Analysis of Volatile Pyrazines

A simple and selective purge-and-trap method for isolation, concentration, and fractionation of volatile pyrazines from a matrix with complex volatiles was developed. A dilute HC1 aqueous solution was used to selectively trap pyrazines from total headspace components from a model system generated product and potato chips. After being titrated to pH 13, the acid-trapped pyrazines were then recovered by the headspace technique and analyzed by GC and GC-MS. Not only can the method quantify minor or trace pyrazines from a very small amount of sample with complex volatiles but also it is much less laborious and time-consuming compared with other traditional isolation, fractionation methods.