Estimation of Fat Soluble Vitamins, Ergocalciferol, and Cholecalciferol in Edible Oil

Importance of the Topic

Vitamin D deficiency is a widespread nutritional issue linked to bone disorders, immune dysfunction and chronic diseases. Since edible oils are commonly consumed and can be fortified, accurate measurement of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) in these matrices is critical to ensure label accuracy and public health.

Objectives and Study Overview

This study aimed to develop and validate a sensitive, reliable LC/MS/MS method for simultaneous quantitation of ergocalciferol and cholecalciferol in edible oil. The approach addresses matrix complexity and delivers a streamlined workflow suitable for routine food testing laboratories.

Used Instrumentation

• Agilent 1290 Infinity II LC system (quaternary pump, multisampler, multicolumn thermostat)
• Agilent InfinityLab Poroshell 120 EC-C18 column (3.0 × 50 mm, 2.7 µm)
• Agilent 6470 triple quadrupole LC/MS with APCI source (positive mode)
• Standard glassware for reflux, volumetric flasks and a nitrogen manifold for evaporation

Methodology and Instrumentation

Sample preparation involved saponification of 1 g oil with ethanolic KOH at 70 °C under nitrogen, followed by hexane extraction. The extract was evaporated and reconstituted in methanol. Chromatographic separation employed a gradient of ammonium acetate with acetic acid in water (mobile phase A) and methanol (mobile phase B) at 0.5 mL/min and 40 °C. MRM transitions for D2 and D3 were optimized (precursor > product ions, collision energies), ensuring specificity.

Major Results and Discussion

Calibration curves (10–500 ng/g) in matrix delivered correlation coefficients > 0.994. The LOQ for both vitamins was 50 ng/g, with system reproducibility %RSDs of 4.7 % for D2 and 3.9 % for D3. Spike recovery at 50 and 100 ng/g levels ranged from 81 % to 90 % across both analytes, demonstrating extraction efficiency and minimal matrix interference. Representative chromatograms confirmed baseline separation and consistent retention times (~6.3 min).

Benefits and Practical Applications

• High sensitivity and specificity in complex oil matrices
• Rapid throughput suited for quality control and nutritional labeling
• Reduced matrix effects via APCI and optimized sample cleanup

Future Trends and Opportunities

Extending this strategy to other fat-soluble vitamins or lipid-based nutrients can enhance comprehensive nutrient profiling. Integration with automated sample preparation and high-resolution MS may further improve throughput and analytical confidence. Regulatory trends toward stricter fortification requirements will increase demand for robust, multi-analyte methods.

Conclusion

The described LC/MS/MS method offers a reliable, reproducible solution for quantifying ergocalciferol and cholecalciferol in edible oils. Its sensitivity, accuracy and streamlined workflow make it well-suited for commercial testing laboratories and regulatory compliance.

References

1. Stevens A.; Dowell J. Determination of Vitamins D2 and D3 in Nutritionals by UPLC-MS/MS. J. AOAC Int. 2012, 95(3).
2. Staffas A.; Nyman M. Collaborative Study on Cholecalciferol in Foods by LC. J. AOAC Int. 2003, 86(2).
3. Agilent Technologies. LC/MS/MS Determination of Vitamin D in Food. Application Note 5990-8627EN, 2011.