Department of Analytical Chemistry, Faculty of Chemistry, Universitat de València, Dr Moliner 50, 46100, Burjassot, Valencia, Spain.
Institut of Material Science (ICMUV), Universitat de València, Catedrático José Beltrán 2, 46980, Paterna, Valencia, Spain.
Anal Chim Acta. 2020 May 8;1110:26-34. doi: 10.1016/j.aca.2020.03.008. Epub 2020 Mar 7.
A novel air sampler has been designed containing a sorbent based on UVM-7 mesoporous silica doped with Ti. The sorbent has been applied for the determination of organophosphorus pesticides in occupational air, followed by gas chromatography with mass spectrometry detection. Thus, several silica materials with different structures (mesoporous UVM-7 and microporous xerogels) were synthesized, and modified with the addition of Ti and Fe. The structure of these materials was proved by transmission electronic microscopy, energy-dispersive X-ray, X-ray diffraction, nitrogen adsorption-desorption and UV-Vis and Raman spectroscopy. The potential of these materials for the retention of pesticides was evaluated and Ti25-UVM-7 was selected as the best solid phase for analyte sorption. Then, several sampling parameters were optimized and analytical features such as breakthrough volume were determined. Using the designed samplers, quantitative retentions were achieved with recoveries in the range 93-107% for all analytes except for diazinon (82%). RSD values below 13% were obtained. Likewise, the sensitivity of the method was studied, and limits of quantification below 0.5 μg m were obtained for all pesticides. The reusability of the material was also proved. The developed procedure has been applied to the air sampling and occupational risk assessment, during and after methyl-chlorpyrifos application in orange plantations. High concentrations and exposure rates above the limit value for ensure safe work conditions were obtained. At the same time, the air was sampled with XAD-2 samplers as a reference method, and results obtained with both devices were statistically comparable.
一种新型空气采样器已被设计出来，其中包含一种基于掺杂 Ti 的 UVM-7 介孔硅的吸附剂。该吸附剂已应用于职业空气中有机磷农药的测定，随后采用气相色谱-质谱联用检测。因此，合成了几种具有不同结构的硅材料（介孔 UVM-7 和微孔干凝胶），并通过添加 Ti 和 Fe 进行改性。通过透射电子显微镜、能谱、X 射线衍射、氮气吸附-脱附和 UV-Vis 以及拉曼光谱证明了这些材料的结构。评估了这些材料对农药保留的潜力，并选择 Ti25-UVM-7 作为分析物吸附的最佳固相。然后，优化了几个采样参数，并确定了分析特征，如穿透体积。使用设计的采样器，除了敌百虫（82%）外，所有分析物的定量保留回收率均在 93-107%范围内。获得了低于 13%的 RSD 值。同样，研究了该方法的灵敏度，所有农药的定量限均低于 0.5μg/m。还证明了材料的可重复使用性。所开发的程序已应用于空气采样和职业风险评估，包括甲基毒死蜱在橙园应用期间和之后。在确保安全工作条件的限值之上，获得了高浓度和暴露率。同时，还使用 XAD-2 采样器作为参考方法进行空气采样，并且两种设备获得的结果在统计学上是可比的。
