Interesting problem with vitamins and antibiotics

[Pedja]

Hi to all people that share same passion

Here is my mixture (veterinary medicine):
1. Oxytetracycline Hydrochloride (antibiotic)
2. Retinol palmitate - Vitamin A
3. Holecalciferole Vit. D3
4. Tocoferol acetate Vit. E
5. Menadion-Natrium-Bisulfite Vit. K
6. Vit. B12 (skip this vitamin - we are determing it microbiologicaly)
7. Riboflavine Vit. B2
8. Nicotine amide Vit. B3
9. Ca-pantotenate Vit. B5

Please share your experience/suggestion about quantification of this mixture. Can you suggest universal solvent or should you do analysis of this product in two or more steps. Please suggest simpliest way to validate analitical method for quantification of this product.

I have Thermo Electron Surveyor device with Hypersil Gold c18 column 100X4.6 mm.

[Pedja]

... so, the mixture od one water soluble antibiotic and lipo/hydro soluble vitamins.

[Bruce Hamilton]

For anybody analysing vitamins, I'd highly recommend starting with :-

" Modern Chromatographic Analysis of Vitamins " by Andre P. De Leenheer, Willy E. Lambert, and Jan F. Van Bocxlaer.
The third 3rd Edition, ISBN 082470316-2 ( 2000 ), has chapters on the analysis of each family of vitamins.

As you are analysing formulated multi-vitamin products, then there proably will be details of the analytical methods in Pharmacopeia or Food Codex, which should also desciribe any precautions needed for quantitative results.

Bruce Hamilton

[Einar Ponten]

Since several years we have experience of doing assays in "vitamin mixtures" like this. Our conclusion is that you will need several different sample pre-treatments and final separation techniques.

Clearly, ZIC®-HILIC works very good for the polar and hydrophilic components using universal detectors like ELSD and UV.