Chemical ionisation mass spectrometry for the measurement of atmospheric amines

2012 ◽  
Vol 9 (3) ◽  
pp. 190 ◽  
Author(s):  
Huan Yu ◽  
Shan-Hu Lee
Keyword(s):  
Real Time ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Detection Limits ◽  
Integration Time ◽  
Fast Time ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Chemical Ionisation ◽  
Ionisation Mass

Environmental contextAmines are of interest to atmospheric chemistry as they may be important gas-phase precursors for secondary aerosol formation. We describe a mass spectrometer for real-time in-situ measurements of gaseous alkyl amines in the atmosphere. This measurement technique will help to evaluate the contribution of amines to the formation of secondary aerosols, including secondary organic aerosol and new particle formation. AbstractWe describe a chemical ionisation mass spectrometer (CIMS) for the ambient measurement of amines, known as important gas-phase precursors for secondary aerosol formation. Protonated ethanol or acetone ions were used as ionisation reagents to selectively detect high proton affinity base compounds (e.g. amines and NH3), thereby minimising interferences from other atmospheric gaseous organic compounds. With ethanol as ionisation reagent (~3 × 105 Hz of ion signals), the CIMS showed similar sensitivities (2.1–8.7 Hz pptv–1) and detection limits (7–41 pptv with a 1-min integration time) for NH3 and several atmospherically relevant key amine compounds containing one to six carbon atoms (C1- to C6-amines and their isomers). The CIMS background signals of the six amines ranged from 9 to 40 pptv, much lower than ~930 pptv for NH3. The CIMS response times were between 13 and 26 s for these amines. The unique combination of the fast time response, high sensitivities and low detection limits allows the use of this CIMS for real time measurements of atmospheric trace amines. During the ambient measurement made in Kent, OH, in November 2011, the measured mixing ratios of C2- and C3-amines were 8 ± 3 (mean ± 1 standard deviation) and 16 ± 7 pptv, whereas those of NH3 were 517 ± 259 pptv.

scholarly journals Measurements of hydroperoxy radicals (HO<sub>2</sub>) at atmospheric concentrations using bromide chemical ionisation mass spectrometry

2019 ◽  
Vol 12 (2) ◽  
pp. 891-902 ◽  
Author(s):  
Sascha R. Albrecht ◽  
Anna Novelli ◽  
Andreas Hofzumahaus ◽  
Sungah Kang ◽  
Yare Baker ◽  
...  
Keyword(s):  
Water Vapour ◽  
Mass Spectrometer ◽  
Ion Source ◽  
Detection Sensitivity ◽  
Detection Methods ◽  
Integration Time ◽  
Key Species ◽  
Atmospheric Concentrations ◽  
Chemical Ionisation ◽  
Ionisation Mass

Abstract. Hydroxyl and hydroperoxy radicals are key species for the understanding of atmospheric oxidation processes. Their measurement is challenging due to their high reactivity; therefore, very sensitive detection methods are needed. Within this study, the measurement of hydroperoxy radicals (HO2) using chemical ionisation combined with a high-resolution time-of-flight mass spectrometer (Aerodyne Research Inc.) employing bromide as the primary ion is presented. The sensitivity reached is equal to 0.005×108 HO2 cm−3 for 106 cps of bromide and 60 s of integration time, which is below typical HO2 concentrations found in the atmosphere. The detection sensitivity of the instrument is affected by the presence of water vapour. Therefore, a water-vapour-dependent calibration factor that decreases approximately by a factor of 2 if the water vapour mixing ratio increases from 0.1 % to 1.0 % needs to be applied. An instrumental background, most likely generated by the ion source that is equivalent to a HO2 concentration of (1.5±0.2)×108 molecules cm−3, is subtracted to derive atmospheric HO2 concentrations. This background can be determined by overflowing the inlet with zero air. Several experiments were performed in the atmospheric simulation chamber SAPHIR at the Forschungszentrum Jülich to test the instrument performance in comparison to the well-established laser-induced fluorescence (LIF) technique for measurements of HO2. A highly linear correlation coefficient of R2=0.87 is achieved. The slope of the linear regression of 1.07 demonstrates the good absolute agreement of both measurements. Chemical conditions during experiments allowed for testing the instrument's behaviour in the presence of atmospheric concentrations of H2O, NOx, and O3. No significant interferences from these species were observed. All of these facts demonstrate a reliable measurement of HO2 by the chemical ionisation mass spectrometer presented.

scholarly journals Real-time secondary aerosol formation during a fog event in London

2009 ◽  
Vol 9 (7) ◽  
pp. 2459-2469 ◽  
Author(s):  
M. Dall'Osto ◽  
R. M. Harrison ◽  
H. Coe ◽  
P. Williams
Keyword(s):  
Real Time ◽  
Chemical Properties ◽  
Formation Mechanisms ◽  
Aerosol Formation ◽  
Urban Background ◽  
Mass Spectrometers ◽  
Secondary Aerosol ◽  
Aerosol Mass ◽  
Heterogeneous Formation ◽  
Specific Particle

Abstract. A fog event was monitored with state-of-the art real-time aerosol mass spectrometers in an urban background location in London (England) during the REPARTEE-I experiment. Specific particle types rich in hydroxymethanesulphonate (HMS) were found only during the fog event. Formation of inorganic and organic secondary aerosol was observed as soon as fog was detected and two different mechanisms are suggested to be responsible for the production of two different types of aerosol. Nitrate aerosol is produced in the liquid phase within the droplet. Contrary to previous studies, the formation of HULIS was observed on interstitial particles rather than evaporated fog droplets, suggesting heterogeneous formation mechanisms depending on parameters other than the water content and not fully understood. Not only are secondary aerosol constituents produced during the fog event, but the primary aerosol is observed to be processed by the fog event, dramatically changing its chemical properties.

scholarly journals Airborne observations of formic acid using a chemical ionisation mass spectrometer

2011 ◽  
Vol 4 (5) ◽  
pp. 5807-5835 ◽  
Author(s):  
M. Le Breton ◽  
M. R. McGillen ◽  
J. B. A. Muller ◽  
A. Bacak ◽  
D. E. Shallcross ◽  
...  
Keyword(s):  
Formic Acid ◽  
Mass Spectrometer ◽  
Limit Of Detection ◽  
Lower Boundary ◽  
Standard Addition ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Chemical Ionisation ◽  
Ionisation Mass ◽  
Ionisation Mass Spectrometer

Abstract. The first airborne measurements of formic acid mixing ratios over the United Kingdom were measured on the FAAM BAe-146 research aircraft on the 16 March 2010 with a chemical ionisation mass spectrometer using I− reagent ions. The I− ionisation scheme was able to measure formic acid mixing ratios at 1 Hz in the lower boundary layer. In-flight standard addition calibrations from a formic acid source were used to determine the instrument sensitivity of 35±6 ion counts pptv−1 s−1 and a limit of detection of 25 pptv. Routine measurements were made through a scrubbed inlet to determine the instrumental background. Three plumes of formic acid were observed over the UK, originating from London, Humberside and Tyneside. The London plume had the highest formic acid mixing ratio throughout the flight, peaking at 358 pptv. No significant correlations of formic acid with NOx and Ozone were found. A trajectory model was employed to determine the sources of the plumes and compare modelled mixing ratios with measured values. The model underestimated formic acid concentrations by up to a factor of 2. This is explained by missing sources in the model, considered to be primary emissions of formic acid of mainly anthropogenic origin and lack of precursor emissions, such as isoprene, from biogenic sources.

scholarly journals Real-time observation of secondary aerosol formation during a fog event in London

2008 ◽  
Vol 8 (6) ◽  
pp. 20019-20050 ◽  
Author(s):  
M. Dall'Osto ◽  
R. M. Harrison ◽  
H. Coe ◽  
P. Williams
Keyword(s):  
Real Time ◽  
Chemical Properties ◽  
Aerosol Formation ◽  
Urban Background ◽  
Mass Spectrometers ◽  
Secondary Aerosol ◽  
Aerosol Mass ◽  
Time Observation ◽  
Real Time Observation ◽  
Specific Particle

Abstract. A fog event was monitored with state-of-the art real-time aerosol mass spectrometers in an urban background location in London (England) during the REPARTEE-I experiment. Specific particle types rich in hydroxymethanesulphonate (HMS) were found only during the fog event. Formation of inorganic and organic secondary aerosol was observed as soon as fog was detected and two different mechanisms are suggested to be responsible for the production of two different types of aerosol. Humic-like substances (HULIS) appear to be produced in the gas phase and condense into the interstitial aerosol, while nitrate aerosol is produced in the liquid phase within the droplet. Not only are secondary aerosol constituents produced during the fog event, but the primary aerosol is observed to be processed by the fog event, dramatically changing its chemical properties.

scholarly journals Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

2013 ◽  
Vol 13 (2) ◽  
pp. 5649-5685 ◽  
Author(s):  
M. Le Breton ◽  
A. Bacak ◽  
J. B. A. Muller ◽  
S. J. O'Shea ◽  
P. Xiao ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Biomass Burning ◽  
Forest Fires ◽  
Hydrogen Cyanide ◽  
Global Emission ◽  
Highly Sensitive ◽  
Research Aircraft ◽  
Chemical Ionisation ◽  
Ionisation Mass ◽  
Ionisation Mass Spectrometer

Abstract. A Chemical Ionisation Mass Spectrometer (CIMS) was developed for measuring hydrogen cyanide (HCN) from biomass burning events in Canada using I− reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO) and acetonitrile (CH3CN) was observed, indicating the potential of HCN as a biomass burning (BB) marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume defining techniques employing CO and CH3CN measurements. The 6 sigma technique produced the highest R2 values for correlations with CO. A Normalised Excess Mixing Ratio (NEMR) of 3.76 ± 0.022 pptv ppbv−1 was calculated which is within the range quoted in previous research (Hornbrook et al., 2011). The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work the emission total for HCN from BB was 0.92 Tg (N) yr−1.

scholarly journals Acid-yield measurements of the gas-phase ozonolysis of ethene as a function of humidity using Chemical Ionisation Mass Spectrometry (CIMS)

2011 ◽  
Vol 11 (9) ◽  
pp. 25173-25204 ◽  
Author(s):  
K. E. Leather ◽  
M. R. McGillen ◽  
M. C. Cooke ◽  
S. R. Utembe ◽  
A. T. Archibald ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Formic Acid ◽  
Gas Phase ◽  
Acid Yield ◽  
Ionisation Mass Spectrometry ◽  
Mass Spectrometry Technique ◽  
Spectrometry Technique ◽  
Reaction With Water ◽  
Chemical Ionisation ◽  
Ionisation Mass

Abstract. Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH) using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing a CH3I ionisation scheme. RHs studied were <1, 11, 21, 27, 30 % and formic acid yields of (0.07 ± 0.01) and (0.41 ± 0.07) were determined at <1 % RH and 30 % RH respectively, showing a strong water dependence. It has been possible to estimate the ratio of the rate coefficient for the reaction of the Criegee biradical, CH2OO with water compared with decomposition. This analysis suggests that the rate of reaction with water ranges between 1 × 10−12–1 × 10−15 cm3 molecule−1 s−1 and will therefore dominate its loss with respect to bimolecular processes in the atmosphere. Global model integrations suggest that this reaction between CH2OO with water may dominate the production of HC(O)OH in the atmosphere.

scholarly journals Influences of emission sources and meteorology on aerosol chemistry in a polluted urban environment: results from DISCOVER-AQ California

2015 ◽  
Vol 15 (23) ◽  
pp. 35057-35115 ◽  
Author(s):  
D. E. Young ◽  
H. Kim ◽  
C. Parworth ◽  
S. Zhou ◽  
X. Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Solar Radiation ◽  
Mass Spectrometer ◽  
Biomass Burning ◽  
Time Of Flight ◽  
Organic Aerosols ◽  
Meteorological Conditions ◽  
Aerosol Formation ◽  
Aerosol Chemistry ◽  
Secondary Aerosol

Abstract. The San Joaquin Valley (SJV) in California experiences persistent air quality problems associated with elevated particulate matter (PM) concentrations due to anthropogenic emissions, topography, and meteorological conditions. Thus it is important to unravel the various sources and processes that affect the physico-chemical properties of PM in order to better inform pollution abatement strategies and improve parameterizations in air quality models. During January and February 2013, a ground supersite was installed at the Fresno-Garland California Air Resources Board (CARB) monitoring station, where comprehensive, real-time measurements of PM and trace gases were performed using instruments including an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and an Ionicon Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF-MS) as part of the NASA Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) campaign. The average submicron aerosol (PM1) concentration was 31.0 μg m−3 and the total mass was dominated by organic aerosols (OA, 55 %), followed by ammonium nitrate (35 %). High PM pollution events were commonly associated with elevated OA concentrations, mostly from primary sources. Organic aerosols had average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), and nitrogen-to-carbon (N / C) ratios of 0.42, 1.70, and 0.017, respectively. Six distinct sources of organic aerosol were identified from positive matrix factorization (PMF) analysis of the AMS data: hydrocarbon-like OA (HOA; 9 % of total OA; O / C = 0.09) associated with local traffic, cooking OA (COA; 28 % of total OA; O / C = 0.19) associated with food cooking activities, two biomass burning OAs (BBOA1; 13 % of total OA; O / C = 0.33 and BBOA2; 20 % of total OA; O / C = 0.60) most likely associated with residential space heating from wood combustion, and semi-volatile oxygenated OA (SV-OOA; 16 % of total OA; O / C = 0.63) and low volatility oxygenated OA (LV-OOA; 24 % of total OA; O / C = 0.90) formed via chemical reactions in the atmosphere. Large differences in aerosol chemistry at Fresno were observed between the current campaign (winter 2013) and a previous wintertime campaign (winter 2010), most notably that PM1 concentrations were nearly three times higher in 2013 than in 2010. These variations were attributed to differences in the meteorological conditions, which influenced primary emissions and secondary aerosol formation. In particular, COA and BBOA concentrations were greater in 2013 than 2010, where colder temperatures in 2013 likely resulted in increased biomass burning activities. The influence from a nighttime formed residual layer that mixed down in the morning was found to be much more intense in 2013 than 2010, leading to sharp increases in ground-level concentrations of secondary aerosol species including nitrate, sulfate, and OOA, in the morning between 08:00 to 12:00 PST. This is an indication that nighttime chemistry might also be higher in 2013. As solar radiation was stronger in 2013 the higher nitrate and OOA concentrations in 2013 could also be partly due to greater photochemical production of secondary aerosol species. The greater solar radiation and larger range in temperature in 2013 also likely led to both SV-OOA and LV-OOA being observed in 2013 whereas only a single OOA factor was identified in 2010.

scholarly journals Real-Time Measurements of Engine-Out Trace Elements: Application of a Novel Soot Particle Aerosol Mass Spectrometer for Emissions Characterization

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
E. S. Cross ◽  
A. Sappok ◽  
E. C. Fortner ◽  
J. F. Hunter ◽  
J. T. Jayne ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Real Time ◽  
Mass Spectrometer ◽  
Soot Particle ◽  
Fast Time ◽  
Engine Fuel ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Measurement Validation

Lubricant-derived trace element emissions are the largest contributors to the accumulation of incombustible ash in diesel particulate filters (DPF), eventually leading to filter plugging and an increase in engine fuel consumption. Particulate trace element emissions also pose adverse health effects and are the focus of increasingly stringent air quality regulations. To date, the rates and physical and chemical properties of lubricant-derived additive emissions are not well characterized, largely due to the difficulties associated with conducting the measurements. This work investigated the potential for conducting real-time measurements of lubricant-derived particle emissions. The experiment used the Soot Particle Aerosol Mass Spectrometer (SP-AMS) developed by Aerodyne Research to measure the size, mass and composition of submicron particles in the exhaust. Results confirm the ability of the SP-AMS to measure engine-out emissions of calcium, zinc, magnesium, phosphorous, and sulfur. Further, emissions of previously difficult to detect elements, such as boron, and low-level engine wear metals, such as lead, were also measured. This paper provides an overview of the results obtained with the SP-AMS, and demonstrates the utility of applying real-time techniques to engine-out and tailpipe-out trace element emissions. Application of the SP-AMS for engine exhaust characterization followed a two-part approach: (1) measurement validation, and (2) measurement of engine-out exhaust. Measurement validation utilized a diesel burner with precise control of lubricant consumption. Results showed a good correlation between CJ-4 oil consumption and measured levels of lubricant-derived trace elements in the particle phase. Following measurement validation, the SP-AMS measured engine-out emissions from a medium-duty diesel engine, operated over a standard speed/load matrix. This work demonstrates the utility of state-of-the-art online techniques (such as the SP-AMS) to measure engine-out emissions, including trace species derived from lubricant additives. Results help optimize the combined engine-lubricant-aftertreatment system and provide a real-time characterization of emissions. As regulations become more stringent and emission controls more complex, advanced measurement techniques with high sensitivity and fast time response will become an increasingly important part of engine characterization studies.

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