Determinação multirresíduo de agrotóxicos por GC-MS/MS em plantas medicinais empregadas na produção de fitoterápicos

Abstract

The use of exotic and Brazilian plants as a resource for therapeutic purposes in the prevention and treatment of diseases, have been evaluated as to the possibility of extracting plant active compounds, as well as the creation of medicinal products for human use. These medicines are called phytomedicines. So, the cultivation of these plants for this purpose should be monitored for the use of pesticides. Currently, Brazilian and international legislation has been showing interest in this public health issue. According to RDC n° 26/2014, the phytomedicines appropriately registered by ANVISA must be submitted to analysis of pesticide residues. In this study, we propose the QuEChERS method (an acronym for Quick, Easy, Cheap, Effective, Rugged and Safe) for the extraction and subsequent multi-residue determination of pesticides in Maytenus ilicifolia (espinheira-santa), Ginkgo biloba L. (Ginkgo biloba) and Mikania glomerata Spreng. (guaco) and Matricaria chamomilla (chamomile). In this method, 1 g of sample was taken into a 50 mL polypropylene tube and 10 mL of ultrapure water was added, followed by vortexing for 1 min and then soaking for 15 min. After 10 mL of acetonitrile (ACN) was added, and the tube was stirred again for 1 min. 4 g of MgSO4, 1 g of NaCl, 1 g of C6H5N3O7.2H2O, 0.5 g of C6H6Na2O7.H2O, followed by vigorous stirring for 1 min and then centrifugation at 6,000 rpm for 8 min at 4 °C. Afterwards, 1 mL of the supernatant was transferred to a 2 mL polypropylene tube containing 150 mg CaCl2 and 50 mg PSA. After that, the centrifugation step was carried out at 10,000 rpm for 8 min at 4 °C. The extract was filtered with 0.2 μm nylon filter. After filtration, the extract was injected into the GC-MS/MS chromatographic system. In the validated QuEChERS method, it obtained recovery results in the range of 70 to 120% and RSD of ≤ 20%. The limit of detection and limit of quantification obtained were 1.5 to 6 μg kg-1 and 5 to 20 μg kg-1, respectively. The method was validated for Ginkgo biloba L. and was applied for the extension of scope in the other matrices.