Vitamin D levels in fish and shellfish determined by liquid chromatography with ultraviolet detection and mass spectrometry.

摘要

Vitamin D₃ (cholecalciferol) levels were determined in finfish and shellfish using UV detection at 265 nm (combined with auxiliary full scan UV detection) and selected ion monitoring (SIM) mass spectrometry (MS), using vitamin D₂ (ergocalciferol) as an internal standard. Analysis of standard reference material (SRM) NIST 1849 (Infant/Adult Nutritional Formula) was included to validate the method. Three-point calibration curves were employed, allowing values to be determined over a range of species, from those having little or no detectable vitamin D₃ (e.g., pollock, shrimp) to those with high levels (e.g., salmon with up to 33.23 micro g/100 g). The limit of detection (LOD) and limit of quantitation (LOQ) calculated from the uncertainty and intercept of the calibration curves were 1.22 micro g/100 g and 5.30 micro g/100 g, respectively, based on all analyses (n=27 sequences). Use of response factors (RF) allowed quantitation at lower levels of vitamin D₃, with an LOQ of <0.20 micro g/100 g. The values obtained using the validated methodology agreed well with literature and tabulated database results for most species. However, much lower average vitamin D₃ concentrations were found for oysters (0.05 micro g/100 g, raw) and clams (0.18 micro g/100 g, cooked) compared to other reports for these products.