Extract-filter-shoot liquid chromatography/mass spectrometry for analysis of vitamin D2 in a powdered supplement capsule and SRM 3280

Authors: Byrdwell, W Craig

Submitted to: Journal of Separation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2014
Publication Date: 6/20/2014
Citation: Byrdwell, W.C. 2014. Extract-filter-shoot liquid chromatography/mass spectrometry for analysis of vitamin D2 in a powdered supplement capsule and SRM 3280. Journal of Separation Science. 10.1002/jssc.201400234.

Interpretive Summary: A 'dilute-and-shoot' method that was previously applied to analysis of vitamin D3 in liquid-filled gelcaps has been modified to convert it to an 'extract-filter-shoot' method for analysis of vitamin D2 in powdered dietary supplements and the compressed powder supplement standard reference material (SRM) 3280 from the National Institute for Standards and Technology (NIST). The method eliminates all time-consuming, labor-intensive and resource-intensive sample preparation steps in the normal analysis of vitamin D2 in powdered and compressed powder dietary supplements. The method was validated by proving that it could produce the correct value for SRM 3280, which has a known amount of vitamin D2. The method also allowed the composition of triacylglycerols in rice flour to be determined. A second modification allowed all four fat soluble vitamins, A, D, E, and K present in SRM 3280 to be identified.

Technical Abstract: An ‘extract-filter-shoot’ method for analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in National Institute of Standards and Technology (NIST) standard reference material (SRM) 3280 is reported. Quantification of vitamin D2 was done by atmospheric pressure chemical ionization mass spectrometry using selected ion monitoring, two transitions of selected reaction monitoring, and extracted ion chromatograms from full scans. UV detection was used for quantification of Vitamin D2 in the dry powder capsule, whereas interfering species rendered UV detection unreliable for SRM 3280. Average values for NIST SRM 3280 ranged from 8.27 ±0.58 ug/g to 8.33 ±0.57 ug/g using internal standard calibration and response factor approaches, compared to the previous NIST internal value of 8.78 ±0.11 ug/g, and the recently updated reference value of 8.6 ± 2.6 ug/g. The powdered supplement capsule (PSC) was found to contain 28.19 ±0.35 ug/capsule to 28.67 ±0.90 ug/capsule for a capsule labeled to contain 25.00 ug. The triacylglycerol composition of the rice flour excipient in the PSC, determined by APCI-MS, is also reported.