Application of high resolution pyrolysis gas chromatography/mass spectrometry (HRPGC/MS) for detecting Listeria monocytogenes

The characteristic of Listeria monocytogenes' pyrolysis product was found by fingerprint analysis of high resolution pyrolysis gas chromatography and mass spectrometry (HRPGC/MS), which hold a great potential to rapidly detect L. monocytogenes with the application of selected ion monitoring (SIM). Food products (beef and milk) contaminated by L. monocytogenes and uncontaminated were evaluated. The retention time of the characteristic peak of pyrolysis product was 19.056 min, the ion of m/z were 54, 98. The results showed that the peak at retention time 19.056 min was detected in agricultural products that contaminated by L. monocytogenes, while the result of the uncontaminated food, there is no peak at the retention time 19.056 min. Qualified by the retention time of chromatographic and mass spectrometry, it can eliminate the interference induced by different types of agricultural products. The results prove united technologies of HRPGC/MS and SIM is not only reliable, reproducible, but also a new method for rapid detecting L. monocytogenes in food products.