Set up of a quick screening method for determination of heavy metals in food, including wine.

INTRODUCTION A number of heavy metals are essential for development of plants and animals at trace concentration, whereas they are toxic at higher levels. Toxicity risk is made higher by their ability to give bioaccumulation and biomagnification. Human being, at the top of food chain, is particularly exposed to this risk From the above, it is clear that heavy metal levels are regulated by national and international laws. For wine, at least in the European Community, highest allowable levels are of 200 ppb for Lead (Pb) and 5 ppm for Zinc (Zn). Routine analysis of food needs robust, quick, and cheap methods for quantification. Up to now, the official method for heavy metal determination in food relays on Atomic Absorption Spectrometry (AAS), which requires time and money consuming pre-treatment of samples for mineralization of them. MATERIALS AND METHODS In the present work, we developed, validated, and applied to market samples a new and innovative metod for the analysis of Zn and Pb in wine, based on Energy Dispersive X-ray analysis (EDX) method. Pre-instrumental work-up is very simple, consisting essentially in the concentration of wine under analysis. Residue is analyzed “as is” in the EDX instrument. RESULTS AND DISCUSSION The above described methodology has been validated analyzing 20 samples of wine, bought in local markets, both with the innovative EDX method and with the more conventional AAS method. Results show that the new method presents high reliability, and could be the method of choice for a quick screening of an high number of samples. Furthermore, Zn and Pb levels in analyzed samples ranged from 0,130 to 0,450 ppm, and from 19 to 78 ppb, respectively, with no sample showing concentration of either metal above the allowed ones.