AbstractThe authors describe a method for the determination of carbonyl pollutants adsorbed on ambient particulate matter (diameter < 2.5 μm; PM2.5). 2,4-Dinitrophenylhydrazine (DNPH) was used to derivatize carbonyl compounds. Magnetic molecularly imprinted polymers (MMIPs) selective for 2,4-DNPH were synthesized to remove excess of the derivatization reagent 2,4-DNPH. Micellar electrokinetic chromatography (MEKC) was then applied to the separation of DNPH-derivatized carbonyl compounds. The increased sensitivity of MEKC with UV detection and the sample cleanup resulted in drastically reduced sampling times (15 min) with detection limits ranging from 0.005–0.068 μg·m−3 for different carbonyls. The method was applied to continuous monitoring of carbonyl compounds on ambient PM 2.5 for two consecutive months. The concentrations and gas-to-particle ratios of carbonyls were determined, and a statistical method was used to evaluate the correlation among different carbonyls. It was observed that the total concentration of carbonyls, especially of multi-carbon carbonyls, increases with the level of air pollution. The level of isovaleraldehyde rises sharply and accounts for 37% of total carbonyls on days with extremely humid haze. The ratio of acetaldehyde to propionaldehyde (C2/C3) decreases with the duration and heaviness of haze conditions. Results indicate that anthropogenic emissions and the characteristics of the atmosphere (e.g. temperature, sunlight, and relative humidity) are the main factors that lead to abnormally high levels of isovaleraldehyde and other carbonyls in ambient PM 2.5. Graphical abstractSchematic of a method for the determination of carbonyl pollutants adsorbed on ambient fine particle of type PM2.5. Magnetic molecularly imprinted polymers (MMIPs) were synthesized to remove the excess derivatization reagent (2,4-DNPH) in air sample prior to CE separation.

中文翻译：

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磁性分子印迹微球样品前处理和毛细管电泳分离定量测定PM2.5型环境颗粒物吸附的羰基污染物

摘要作者描述了一种测定吸附在环境颗粒物（直径 < 2.5 μm；PM2.5）上的羰基污染物的方法。2,4-二硝基苯肼 (DNPH) 用于衍生羰基化合物。合成了对 2,4-DNPH 具有选择性的磁性分子印迹聚合物 (MMIP)，以去除过量的衍生化试剂 2,4-DNPH。然后将胶束电动色谱 (MEKC) 应用于分离 DNPH 衍生的羰基化合物。具有 UV 检测和样品净化的 MEKC 增加的灵敏度导致采样时间（15 分钟）大幅减少，不同羰基化合物的检测限范围为 0.005–0.068 μg·m-3。该方法用于连续两个月连续监测环境 PM 2.5 中的羰基化合物。测定羰基化合物的浓度和气粒比，并使用统计方法评估不同羰基化合物之间的相关性。据观察，羰基化合物的总浓度，尤其是多羰基化合物，随着空气污染程度的增加而增加。异戊醛水平急剧上升，在雾霾极其潮湿的日子里占总羰基化合物的 37%。乙醛与丙醛的比率 (C2/C3) 会随着雾霾条件的持续时间和严重程度而降低。结果表明，人为排放和大气特征（例如温度、阳光和相对湿度）是导致环境 PM 2.5 中异戊醛和其他羰基化合物含量异常高的主要因素。图解 测定吸附在环境 PM2.5 细颗粒物上的羰基污染物的方法示意图。合成磁性分子印迹聚合物 (MMIP) 以在 CE 分离之前去除空气样品中过量的衍生化试剂 (2,4-DNPH)。