Detection of regulated herbs and plants in plant food supplements and traditional medicines using infrared spectroscopy.

The identification of a specific toxic or regulated plant in herbal preparations or plant food supplements is a real challenge, since they are often powdered, mixed with other herbal or synthetic powders and compressed into tablets or capsules. The classical identification approaches based on micro- and macroscopy are therefore not possible anymore. In this paper infrared spectroscopy, combined with attenuated total reflectance was evaluated for the screening of plant based preparations for nine specific plants (five regulated and four common plants for herbal supplements). IR and NIR spectra were recorded for a series of self-made triturations of the targeted plants. After pretreatment of the spectral data chemometric classification techniques were applied to both data sets (IR and NIR) separately and the combination of both. The results show that the screening of herbal preparations or plant food supplements for specific plants, using infrared spectroscopy, is feasible. The best model was obtained with the Mid-IR data, using SIMCA as modelling technique. During validation of the model, using an external test set, 21 of 25 were correctly classified and six of the nine targeted plants showed no misclassifications for the selected test set. For the other three a success rate of 50% was obtained. Mid-IR combined with SIMCA can therefore be applied as a first step in the screening of unknown samples, before applying more sophisticated fingerprint approaches or identification tests described in several national and international pharmacopoeia. As a proof of concept five real suspicious samples were successfully screened for the targeted regulated plants.

The use of Stationary Phase Optimized Selectivity Liquid Chromatography for the development of herbal fingerprints to detect targeted plants in plant food supplements.

The consumption of plant food supplements is increasing steadily and more and more, these products are bought through internet. Often the products sold through internet are not registered or declared with a national authority, meaning that no or minimal quality control is performed and that they could contain herbs or plants that are regulated. Stationary Phase Optimized Selectivity Liquid Chromatography (SOS-LC) was evaluated for the development of specific fingerprints, to be used for the detection of targeted plants in plant food supplements. Three commonly used plants in plant food supplements and two regulated plants were used to develop fingerprints with SOS-LC. It was shown that for all plants specific fingerprints could be obtained, allowing the detection of these targeted plants in triturations with different herbal matrices as well as in real samples of suspicious supplements seized by the authorities. For three of the five plants a more specific fingerprint was obtained, compared to the ones developed on traditional columns described in literature. It could therefore be concluded that the combination of segments of different types of stationary phases, as used in SOS-LC, has the potential of becoming a valuable tool in the quality control and the identification of crude herbal or plant material and in the detection of regulated plants in plant food supplements or other herbal preparations.