We describe the airborne deployment of an extractive electrospray time-of-flight mass spectrometer (EESI-MS). The instrument provides a quantitative 1 Hz measurement of the chemical composition of organic aerosol up to altitudes of 7 km, with single-compound detection limits as low as 50 ng per standard cubic meter.
We describe the airborne deployment of an extractive electrospray time-of-flight mass...
Review status: a revised version of this preprint was accepted for the journal AMT and is expected to appear here in due course.
Airborne Extractive Electrospray Mass Spectrometry Measurements of the Chemical Composition of Organic Aerosol
Demetrios Pagonis1,2,Pedro Campuzano-Jost1,2,Hongyu Guo1,2,Douglas A. Day1,2,Melinda K. Schueneman1,2,Wyatt L. Brown1,2,Benjamin A. Nault1,2,a,Harald Stark1,2,3,Kyla Siemens4,Alex Laskin4,Felix Piel5,6,Laura Tomsche7,8,Armin Wisthaler6,9,Matthew M. Coggon2,10,Georgios I. Gkatzelis2,10,c,Hannah S. Halliday8,b,Jordan E. Krechmer3,Richard H. Moore8,David S. Thomson11,Carsten Warneke2,10,Elizabeth B. Wiggins8,and Jose L. Jimenez1,2Demetrios Pagonis et al.Demetrios Pagonis1,2,Pedro Campuzano-Jost1,2,Hongyu Guo1,2,Douglas A. Day1,2,Melinda K. Schueneman1,2,Wyatt L. Brown1,2,Benjamin A. Nault1,2,a,Harald Stark1,2,3,Kyla Siemens4,Alex Laskin4,Felix Piel5,6,Laura Tomsche7,8,Armin Wisthaler6,9,Matthew M. Coggon2,10,Georgios I. Gkatzelis2,10,c,Hannah S. Halliday8,b,Jordan E. Krechmer3,Richard H. Moore8,David S. Thomson11,Carsten Warneke2,10,Elizabeth B. Wiggins8,and Jose L. Jimenez1,2
Received: 30 Sep 2020 – Accepted for review: 06 Oct 2020 – Discussion started: 07 Oct 2020
Abstract. We deployed an extractive electrospray ionization time-of-flight mass spectrometer (EESI-MS) for airborne measurements of biomass burning aerosol during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) study onboard the NASA DC-8 research aircraft. Through optimization of the electrospray working solution, active control of the electrospray region pressure, and precise control of electrospray capillary position, we achieved 1 Hz quantitative measurements of aerosol nitrocatechol and levoglucosan concentrations up to pressure altitudes of 7 km. EESI-MS response to levoglucosan and nitrocatechol was calibrated for each flight, with flight-to-flight calibration variability of 60 % (1σ). Laboratory measurements showed no aerosol size dependence in EESI-MS sensitivity below particle geometric diameters of 400 nm, covering 82 % of accumulation mode aerosol mass during FIREX-AQ. We also present a first in-field intercomparison of EESI-MS with a chemical analysis of aerosol online proton-transfer-reaction mass spectrometer (CHARON PTR-MS) and a high-resolution Aerodyne aerosol mass spectrometer (AMS). EESI-MS and CHARON PTR-MS levoglucosan concentrations were well correlated, with a regression slope of 0.94, R2 = 0.77. AMS levoglucosan-equivalent concentrations and EESI-MS levoglucosan showed greater difference, with a regression slope of 1.36, R2 = 0.96, likely indicating the contribution of other compounds to the AMS levoglucosan-equivalent measurement. Total EESI-MS signal showed correlation (R2 = 0.9) with total organic aerosol measured by AMS, and the EESI-MS bulk organic aerosol sensitivity was 60 % of the sensitivity to levoglucosan standards.
We describe the airborne deployment of an extractive electrospray time-of-flight mass spectrometer (EESI-MS). The instrument provides a quantitative 1 Hz measurement of the chemical composition of organic aerosol up to altitudes of 7 km, with single-compound detection limits as low as 50 ng per standard cubic meter.
We describe the airborne deployment of an extractive electrospray time-of-flight mass...