Rapid analysis and identification of meat species by laser-ablation electrospray mass spectrometry (LAESI-MS)

Abstract

RATIONALE: Laser-ablation electrospray ionization mass spectrometry (LAESI-MS) was applied to analyze fresh meat species without sample pretreatment. The study demonstrates that the LAESI-MS technique is a promising, rapid and accurate method for meat identification using a protocol combining principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). METHODS: A focused IR-laser was used for meat sample ablation at a wavelength of 2940 nm. The ablated particulates were carried through a transfer PTFE tube using air as carrier gas, delivered to the electrospray plume and ionized. A TOF-MS was used to detect the ion signal. The raw mass spectra were analyzed using the PCA and PLS-DA protocol. RESULTS: Five fresh meat samples, chicken, duck, pork, beef and mutton, were identified by the developed LAESI-MS technique using the protocol combining PCA and PLS-DA. The discrimination accuracy of all meat species is 100%, and the score plot also shows good identifying ability. CONCLUSIONS: Five fresh meat samples were analyzed using the LAESI-MS technique. Each set of raw mass data was collected within 30 s and analyzed by the PCA and PLS-DA protocol. Eighteen, 19, 18, 17, and 15 markers for chicken, duck, pork, beef, and mutton, respectively, have been selected successfully for meat identification. The results demonstrate that LAESI-MS is a new reliable and rapid method for meat identification.