Levels of Previtamin D and Vitamin D in milk

[carol]

Hi,

Has anyone measured levels of vitamin D and Previtamin D in fortified and unfortified milk, infant formulas?

Thanks Carol

[James_Ball]

Hi,

Has anyone measured levels of vitamin D and Previtamin D in fortified and unfortified milk, infant formulas?

Thanks Carol

I did vitamin D2 and D3 several years ago in infant formula for a NIST blind study. It wasn't to difficult by LCMSMS.

[carol]

Hi,

Thanks for your replay, I did set up a method, but my question is, did you manage to separate vitamin D3 and previtamin D3?.


Thanks,
Carol

[James_Ball]

Hi,

Thanks for your replay, I did set up a method, but my question is, did you manage to separate vitamin D3 and previtamin D3?.


Thanks,
Carol

We weren't looking for the previtamin so I am not sure we were separating it. The method I ran was based on this publication

http://www.restek.com/Technical-Resourc ... nsics_A015

Using an Acetonitrile extraction we were able to get good recoveries from infant formula and from calcium/vitaminD supplement tablets.

[JMB]

See,

See, J.M. Ballard et al, Identification of Degradates of Vit. D3, J.Pharm. & Biomed. Anal. 43 (2007) 142-150.

HPLC method is,

Aliquots (100 L) of the solution (sample tray at 5 C) were injected onto an HP 1100 liquid chromatograph. Data were collected by a VG Multichrom system. Gradient chromatography was performed on a Platinum EPS C18 column (150 x 4.6 mm; 3 m particles) held at 17 C, with UV detection at 265 nm. The organic component of the mobile phase was acetonitrile, while the aqueous component was 0.1% phosphoric acid. Gradient program: %-organic (time, min.), 4 (0), 4 (7), 80 (20), 85 (48), 95 (50), 95 (60), 100 (61), 100 (68), 4 (75).

Major excipient RT ~21 min
pre-vit. D3 ~38 min
vitamin D3 ~42 min

0.1 % H3PO4 in aqueous was found to help peak shape.

You can modify HPLC program to suit your needs. Many, Many columns were tested &
Platinum EPS C18 column was found to be the best at the time this work was performed (about 2004-5).