Compositional Analysis of Adsorbed Organic Aerosol on a Microresonator Mass Sensor

Abstract

Aerosol mass measurements are a key air pollution parameter that is regulated in most countries. Beyond mass measurements, the precise composition of the aerosol is essential in identifying sources and impacts on health and climate. The conventional method for simultaneously quantifying mass and composition is to collect aerosol onto filter or impactor samples followed by laboratory analysis. This approach requires long collection times-providing poor time resolution for mass measurementsand long sample preparation prior to analysis. The first limitation can be circumvented with microresonators, which are novel particulate mass sensors with high mass sensitivities and time resolutions. In addition, direct surface analysis techniques, like liquid extraction surface analysis mass spectrometry (LESA-MS), shorten sample preparation times. This work combines, for the first time, the high time resolution mass measurements of a microresonator with the integrated compositional analysis of LESA-MS. Laboratory-produced secondary organic aerosol were collected onto a microresonator via impaction with LESA-MS being used to analyze the chemical composition afterwards. The results were compared with classic filter extraction methods and literature with the final spectra matching the expected reaction products. The combined technique demonstrates an extension to current microresonator applications and illustrates their potential for ambient aerosol studies.

An Automated Methodology for Non-targeted Compositional Analysis of Small Molecules in High Complexity Environmental Matrices Using Coupled Ultra Performance Liquid Chromatography Orbitrap Mass Spectrometry

“…Internal standards are also plagued by the same challenge, i.e., often not representative of the sheer number of chemically diverse compounds present in environmental matrices. Here, we used common practice sample extraction procedures for PM (e.g., ref ( 68 ) and references therein). We did not however investigate the recovery efficiencies of the authentically identified compounds and therefore recommend that in future work, such analysis is performed to quantify any potential losses and provide insight into the quality of the extraction procedure.…”

Direct Depolymerization Coupled to Liquid Extraction Surface Analysis-High-Resolution Mass Spectrometry for the Characterization of the Surface of Plant Tissues

“…Data were then filtered using a Mathematica 10 (Wolfram Research Inc., U.K.) code developed in-house and already described elsewhere, which uses a series of rules (e.g., nitrogen rule, isotope ratios) and element ratios (O/C ≤ 2, H/C ≥ 0.3, H/C ≤ 2.5, N/C ≤ 0.5, S/C ≤ 0.2) to determine a list of chemically meaningful formula assignments. More details about instrumental settings, calibrations, and data processing procedures can be found elsewhere. ,, The following discussion refers to CHO compounds only, which are the most relevant cuticle building-blocks and represent almost entirely the compounds detected in this study.…”

“…More details about instrumental settings, calibrations, and data processing procedures can be found elsewhere. 13,29,30 The following discussion refers to CHO compounds only, which are the most relevant cuticle building-blocks 11 and represent almost entirely the compounds detected in this study. Statistical Analysis.…”

Towards Portable MEMS Oscillators for Sensing Nanoparticles

“…Current approaches include commercial condensation particle counters, but these provide an estimate of number concentration rather than a direct measure of total mass or mass concentration and require a system to enlarge the particles to a sufficiently large diameter through vapor condensation prior to detection. Additionally, once particulates are collected onto the surface of a MEMS sensor, other techniques can be applied for further characterization including compositional analysis [ 18 ]. This paper demonstrates the applicability of MEMS sensors, specifically piezoelectric-on-silicon resonant mass sensors, for detecting ultrafine particles following on previous work [ 19 ] applied to two use cases viz.…”