Vapor- and aerosol-phase atmospheric organic matter were collected in East St. Louis, MO using the high-volume sampling method. Samples were processed by traditional analytical methods and analyzed by multidimensional gas chromatography with time-of-flight mass spectrometric detection. Levels of identified, hydrocarbon-like organic vapor and aerosol species (i.e., HOV and HOA, respectively) were 10–42 ng m⁻³ and 0.020–3.6 ng m⁻³, respectively. Concentrations of identified, oxygenated organic vapor and aerosol species (i.e., OOV and OOA, respectively) were 2–66 ng m⁻³ and 23–310 ng m⁻³, respectively. The principal feature of the HOV was an unresolved complex mixture that represented 54.5 ± 11.3% of the total HOVs during the field campaign. Levels of n- and branched alkanes, alkyl and cycloalkylbenzenes, polyaromatic hydrocarbons (PAHs), and alkyl-substituted PAHs generally declined from the morning rush hour to the 1000–1400 sampling period, which was similar to the expected trend in reactivity with respect to OH. The OOV included aliphatic mono-carboxylic acids, aliphatic and aromatic alcohols, aldehydes, and ketones, and alicyclic ketones, alcohols, and epoxides (i.e., montoterpenoids). The bulk of the OA species (∼99%) were a complex mixture of OOA, which included multifunctional n-aliphatic, alicyclic, and aromatic hydrocarbons, dicarboxylic and ketocarboxylic aliphatic and dicarboxylic monoaromatic acids, lactones, tetrols, and pentitols. The sampling and analytic techniques provided quantitative molecular information for HOVs in ambient air, which are a missing source of secondary organic aerosol precursors. Molecular characterization and quantitation of HOVs and OOA species will facilitate predictions of SOA formation using molecular-specific models.

在密苏里州东圣路易斯使用大容量采样方法收集了气相和气溶胶相大气有机物。样品通过传统的分析方法处理，并通过多维气相色谱和飞行时间质谱检测进行分析。已确定的类烃有机蒸气和气溶胶物质（即分别为 HOV 和 HOA）的水平分别为 10-42 ng m ^-3和 0.020-3.6 ng m ^-3。已确定的含氧有机蒸气和气溶胶物质（即分别为 OOV 和 OOA）的浓度为 2-66 ng m ^-3和 23-310 ng m ^-3， 分别。HOV 的主要特征是未解决的复杂混合物，占野外活动期间总 HOV 的 54.5 ± 11.3%。的水平ñ -和支链烷烃，烷基和环烷基苯，聚芳烃（PAHs的），和烷基取代的多环芳烃通常从早晨上班高峰时间下降到1000-1400采样周期，这类似于在反应相对于预期的趋势哦。OOV 包括脂肪族单羧酸、脂肪族和芳香族醇、醛和酮，以及脂环族酮、醇和环氧化物（即类单萜）。大部分 OA 物种（~99%）是 OOA 的复杂混合物，其中包括多功能n-脂族、脂环族和芳族烃、二羧酸和酮羧酸脂族和二羧酸单芳族酸、内酯、四醇和戊醇。采样和分析技术为环境空气中的 HOV 提供了定量的分子信息，这是二次有机气溶胶前体的缺失来源。HOV 和 OOA 种类的分子表征和定量将有助于使用分子特异性模型预测 SOA 的形成。