Analysis of Vitamin D3 in Meat-Based Ready-To-Eat (RTE) Products: A Comparative Study of Extraction Methods (SPE and DLLME) Using LC–MS/MS

Vitamin D is a crucial nutrient, and its accurate quantification in food matrices, such as meat and egg, is vital for nutritional and health assessments. In the present study, two extraction methods, i.e., solid phase extraction (SPE) and dispersive liquid–liquid microextraction (DLLME), after sample hydrolysis by saponification, were compared for better vitamin D extraction from the samples. The extracted analyte was analyzed using liquid chromatography-tandem mass spectrometry (LC–MS/MS) by electron spray ionization method. The efficiency of the SPE method was tested with petroleum ether, chloroform, n-heptane, and dichloromethane solvents through C-18 Oasis cartridge, while the DLLME method was evaluated with varying combinations of extraction solvents (toluene, carbon tetrachloride, chloroform, and dichloromethane) and dispersive solvents (acetone, acetonitrile, and ethanol). The results showed that the recovery of the vitamin in the SPE method ranged between 8.6 and 17.2%, with the maximum recovery achieved using petroleum ether. On the other hand, the DLLME method yielded a broader range of recovery (2.4–118.9%) for the different combinations of dispersive and extraction solvents. As the maximum recovery was obtained for the combination of toluene and acetone in DLLME method, this was selected for further studies to extract vitamin D3 from boiled egg, cooked fish, and ready-to-eat food products (chicken biryani, chicken pulav, chicken soup, chicken curry, and chicken kurma). The vitamin D3 content in the food products varied in the range of 11.6–136.4 µg/kg, where boiled egg (11.6 ± 8.7 µg/kg) and fish (136.4 ± 8.8 µg/kg) had minimum and maximum quantities, respectively.

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