Rapid recognition of irradiated dry-cured ham by on-line coupling of reversed-phase liquid chromatography with gas chromatography and mass spectrometry

The use of on-line coupling of reversed-phase liquid chromatography and gas chromatography (RPLC-GC) with the through oven transfer adsorption desorption (TOTAD) interface and mass spectrometry (MS) was proposed for testing different types of commercial Spanish dry-cured ham for irradiation treatment at various doses (0, 1.5, 2, and 4 kGy). The qualitative analysis of radiation-specific compounds (e.g., n-pentadecane, 1-hexadecene, 1,7-hexadecadiene, n-heptadecane, 8-heptadecene, and 2-dodecylcyclobutanone) can be simultaneously established in a single run with samples that have or have not been irradiated. The overall analysis, which takes less than 100 min, includes a rapid extraction step using a small amount of dichloromethane-methanol (1:1, vol/vol) and anhydrous sodium sulfate, the subsequent fractionation of the sample in the first dimension of the system (RPLC), the transfer of the target fraction to the second dimension, the GC separation, and the MS detection. The calculated limits of detection in ham were lower than 22 ng/g. Repeatability studies provided relative standard deviation values of 0.8 to 13.5%.