Contamination of endemic plants of Amazonia by ubiquitary pollution: Persistent organic pollutants (POPs) determination by GC-MS/MS

We report on the results of an analytical investigation about the contamination on three officinal plants of Amazonian rain forest due to Persistent Organic Pollutants (POPs), like organochlorine pesticides and polychlorinated biphenyls (PCBs). The analyzed plants ­ "balsamina" (Impatiens Balsamina), "mullaca" (Physalis Angulata) and "graviola" (Annona Muricata) ­ come from the Amazonian forest of the Peru where they grow spontaneously. All the three plants are well known for their numerous therapeutic properties and commonly they are used in the traditional medicine against several diseases like cancer, fever, diabetes, etc. A portion of about l0 g for each vegetable sample was submitted to extraction procedure with hexane­acetone (1:1, v/v) solution by using soxhlet technique for 24h, following procedures by ISTISAN 99/28. The three extracts were analyzed by Gas Chromatography­Tandem Mass Spectrometry (GC­MS/MS) and Multi Reaction Monitoring (MRM) techniques (by using ion trap detector Varian Saturn 2200 system) after their purification by chromatography on celite column eluted with n­hexane (ISTISAN 99/25). The obtained results show the presence of DDT and its metabolites, like DDD e DDE in the three analyzed samples and of hexachlorobenzene only in the "graviola" (0.041 μg/kg). The total POPs quantities are in the concentration range of ppb, varying from 0.349 and 0.614 μg/kg respectively for "mullaca" and "graviola", up to 2.328 μg/kg in the case of "balsamina". These concentration values are an indication of a plants contamination in trace due to the organochlorinated pesticides coming from an ubiqitary pollution and not from a direct use of these substances in the place of origin of the samples. Finally, concerning the PCBs determination, the analysis GC­MS/MS excludes their presence in all the three plants investigated: the concentration values are in this case lower than the detection limit of the method (0.003­0.013 μg/kg).