2.3. Sample preparation
Seven ham samples purchased from a local supermarket were pre-treated by homogenization in a triturator and stored at 4 °C during the study. These included four samples of cooked pork ham (samples 1–4), two samples of cooked turkey ham (samples 5–6) and one sample of dried ham (sample 7). All samples were from different brands.
Five different sample preparation procedures were tried. One set of samples was extracted with hot water (50–60 °C) and clarified by filter through filter paper and membrane filter. Two sets of samples were extracted with hot water (50–60 °C) and deproteinized, one with acetonitrile and the other with Carrez reagents and filtered. One set of samples was dried for 1 h in an oven, extracted with hot water (50–60 °C), added of 1 g activated charcoal, deproteinized with acetonitrile and filtered. Another set of samples was extracted with hot water (50–60 °C), deproteinized with acetonitrile and purified with sep-pak C18. A summarized description of the analytical methods assessed is presented in Table 1.