Context: The shark liver of the species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, captured in the north-central coast of Cuba are a source of oil, whose content of major fatty acids could be used in its quality control. Aims: To develop a simple and robust gas chromatography with a flame ionization detector (GC-FID) method that is suitable for routine analysis of four major fatty acids extracted shark liver oil. Methods: Four major fatty acid content in shark liver oil pool of species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, was analyzed through the gas chromatography with a GC-FID. The fatty acids were analyzed as methyl esters derivatives, using 5% aqueous sulfuric acid in methanol. The method was validated in terms of linearity, precision, accuracy, specificity and limit of detection and quantitation. Results: Under the optimum analytical conditions, the analysis revealed that each target component was well separated with satisfactory recoveries and reproducibility. The method linearity was found to be high with good determination coefficient values for all target components. The evaluation of the matrix effect, demonstrated, that there is not interference from substances other than analysis. The method was also found to be accurate, precise and reproducible and it was applied to the quantitative determination of the fatty acid content in shark liver oil pool; oleic acid was the most abundant fatty acid (22.69%), followed by palmitic (18.85%), stearic (6.01 %) and myristic acid (0.40 %). Conclusions: The GC-FID developed method is reliable and suitable for determination of four major fatty acids in shark liver oil pool.

Context: The shark liver of the species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, captured in the north-central coast of Cuba are a source of oil, that when extracted it must be purified due to its bad smell, taste and the amount of impurities it has. Aims: To evaluate the purification of the shark liver oil (SLO) pool of species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, by Cuban bentonite clay. Methods: The effects of bentonite dose, contact time and speed rate were studied using the 23 factorial designs. The parameters are evaluated in the experiment design: acidity value, p-anisidine value, peroxide value, Totox value and Bleaching performance. Response Surface Methodology modeling techniques were applied to model the process and their performance and predictive capabilities of the response (purification efficiency) was also examined. Results: The experiments showed that the oil is suitable for consumption after the purification process. The best treatment, which could reduce the impurities in the SLO pool, was a treatment with bentonite dose at 80 g/L, time at 15 min, and speed rate at 250 rpm. Cuban bentonite clay is a promising adsorbent candidate for the removal of impurities of the SLO. Conclusions: The local Cuban bentonite clay can be used as potential low-cost adsorbent for shark liver oil pool purification, as showed the experiments.