Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6627, 31270901, Belo Horizonte, MG, Brazil.
Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6627, 31270901, Belo Horizonte, MG, Brazil.
Anal Chim Acta. 2019 Apr 25;1054:26-37. doi: 10.1016/j.aca.2018.12.017. Epub 2018 Dec 24.
The extensive use of pesticides promotes environmental contamination, mainly in surface and ground waters. However, they remain at very low concentration and present wide degradation level requiring the use of efficient devices for pesticides passive sampling. In this study, a new in situ passive sampling device was developed for monitoring and estimating time-weighted average (TWA) of pesticides in waters. The device was made with simple, recyclable and cheap materials. The sampling system involves the liquid phase microextraction technique with hollow fiber in two-phases mode. Pesticides determination was done by gas chromatography coupled to mass spectrometry. The method was optimized and validated for the determination of 29 pesticides in water, showing good linearity in the range between 0.012 and 40.00 μg L with determination coefficients of R > 0,9649. Limit of detection (LOD) ranged from 0.009 to 0.557 μg L and limit of quantification (LOQ) from 0.012 to 0.802 μg L. The recoveries of spiked pesticides in water samples were in the range from 96 to 130%. The method was applied to forty environmental water samples collected at São Francisco river basin, Brazil. The highest detection frequency was found for the pesticides 4,4-DDE, 4,4-DDD and propazine. They were detected in more than 20 percent of the samples.
农药的广泛使用促进了环境污染，主要是地表水和地下水的污染。然而，它们的浓度仍然非常低，且存在广泛的降解水平，这就需要使用高效的农药被动采样设备。在这项研究中，开发了一种新的原位被动采样装置，用于监测和估计水中农药的时间加权平均值（TWA）。该装置由简单、可回收和廉价的材料制成。采样系统涉及两相模式下的中空纤维液相微萃取技术。采用气相色谱-质谱联用技术对农药进行测定。该方法对水中 29 种农药进行了优化和验证，在 0.012 至 40.00μg/L 的范围内具有良好的线性关系，相关系数 R>0.9649。检测限（LOD）范围为 0.009 至 0.557μg/L，定量限（LOQ）范围为 0.012 至 0.802μg/L。在水样中添加的农药回收率在 96%至 130%之间。该方法应用于巴西圣弗朗西斯科河流域采集的四十个环境水样。在这些水样中，4,4-DDE、4,4-DDD 和普草津的检出频率最高。它们在超过 20%的样本中被检测到。
