The Study is here:
http://onlinelibrary.wiley.com/doi/10.1002/dta.1853/full
Conclusion:
The newly developed UHPLC-PDA method facilitated the detection of vinpocetine and picamilon. This method exhibited excellent performance in terms of sensitivity and is a suitable method for rapid analysis of vinpocetine and picamilon in dietary supplements. The developed method was validated for all the parameters tested and successfully applied to the identification of vinpocetine in authenticated plant samples and dietary supplements.
As expected, vinpocetine was not detected in 2 authenticated samples of Vinca minor. Of the 23 vinpocetine dietary supplements tested, 17 contained vinpocetine and the quantity of vinpocetine in these supplements ranged from 0.3 to 32 mg per recommended daily serving. No vinpocetine was detected in 26% (6/23) of the sampled supplements. Vinpocetine was sold as if it were a constituent of lesser periwinkle in 13% (3/23) of the supplements. In summary, 39% (9/23) of the vinpocetine supplements were misbranded, and 74% (17/23) of vinpocetine supplement labels did not provide any information on the quantity of vinpocetine.
Of the 31 picamilon supplements tested, 30 contained picamilon and the quantity of picamilon ranged from 2.7 to 721.5 mg per maximum recommended daily serving. In the supplements providing a specific quantity of picamilon on the label, actual quantity of picamilon ranged from 99.6 to 157.9% of labelled quantity.
