| Autor: |
Silva TLR; Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., de Queiroz MELR; Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., de Oliveira AF; Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Rodrigues AAZ; Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.; Department of Agricultural Engineering, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Neves AA; Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Vieira PAF; Department of Nutrition and Health, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., de Queiroz JH; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil., Barbosa VOP; Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil. |
| Abstrakt: |
Urine is one of the biological matrices most used for detecting human contamination, as it is representative and easily obtained via noninvasive sampling. This study proposes a fast, accurate, and ecological method based on liquid-liquid microextraction with low-temperature partition (μLLE/LTP). It was validated to determine nine pesticides (lindane, alachlor, aldrin, chlorpyrifos, dieldrin, endrin, DDT, bifenthrin, and permethrin) in human urine, in association with gas chromatography coupled with mass spectrometry (GC-MS). The technique was optimized through a factorial design. The best conditions for the simultaneous extraction of the analytes comprised the addition of 600 µL of water and 600 µL of acetonitrile (extracting solvent) to a 500-µL urine sample, followed by vortexing for 60 s. By freezing the samples for 4 h, it was possible to extract the pesticides and perform the extract clean-up simultaneously. The parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy were used to appraise the performance of the method. Good values of selectivity and linearity ( R 2 > 0.990), LOQ (0.39-1.02 μg L -1 ), accuracy (88-119% recovery), and precision (%CV ≤ 15%) were obtained. The μLLE/LTP-GC-MS method was applied to authentic urine samples collected from volunteers in Southeast Brazil. |
