Li Mingxiao, Li Qi, Nantz Michael H, Fu Xiao-An
Department of Chemical Engineering and Department of Chemistry, University of Louisville, 216 Eastern Parkway, Louisville, Kentucky 40208, United States.
ACS Omega. 2018 Jun 30;3(6):6764-6769. doi: 10.1021/acsomega.8b00503. Epub 2018 Jun 21.
Aldehydes including formaldehyde, acetaldehyde, and acrolein are toxic organic components of air pollution that cause lung cancer and cardiovascular disease with chronic exposure. The commonly used method for determining the levels of carbonyl compounds based on the derivatizing agent 2,4-dinitrophenylhydrazine is of limited use for ketones and unsaturated aldehydes because of issues such as low capture efficiencies, unstable derivatives, and long sample collection times. This work details the analysis of carbonyls in ambient air by a microreactor approach. The microreactor is fabricated on a silicon wafer and has thousands of micropillars in a microfluidic channel for uniformly distributing the air flow through the channel. The surfaces of the micropillars are coated with a quaternary ammonium aminooxy reagent, 2-(aminooxy)ethyl-,,-trimethylammonium iodide (ATM), for chemoselective capture of carbonyl compounds by means of oximation reactions. ATM-carbonyl adducts are eluted from the microreactor and directly analyzed by Fourier transform ion cyclotron resonance mass spectrometry and ultrahigh-performance liquid chromatography-mass spectrometry. More than 20 carbonyls were detected in ambient air samples. Acetone, 2-butanone, acetaldehyde, and formaldehyde were the most abundant carbonyls in ambient air of the studied urban areas.
包括甲醛、乙醛和丙烯醛在内的醛类是空气污染中的有毒有机成分，长期接触会导致肺癌和心血管疾病。基于衍生剂2,4-二硝基苯肼测定羰基化合物含量的常用方法，对于酮类和不饱和醛类的应用有限，原因包括捕获效率低、衍生物不稳定以及样品采集时间长等问题。这项工作详细介绍了通过微反应器方法分析环境空气中的羰基化合物。该微反应器制作在硅片上，在微流体通道中有数千个微柱，用于使气流均匀分布通过该通道。微柱表面涂有季铵氨氧基试剂2-(氨氧基)乙基三甲基碘化铵（ATM），通过肟化反应对羰基化合物进行化学选择性捕获。ATM-羰基加合物从微反应器中洗脱出来，然后直接通过傅里叶变换离子回旋共振质谱和超高效液相色谱-质谱进行分析。在环境空气样品中检测到了20多种羰基化合物。在所研究城市地区的环境空气中，丙酮、2-丁酮、乙醛和甲醛是含量最高的羰基化合物。
