Improved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)

Abstract. Particulate chloride is an important component of fine particulate matter in marine air masses. Recent field studies also report elevated concentrations of gas-phase reactive chlorine species and particulate chloride related to anthropogenic activities. This work focuses on particulate chloride detection and quantification issues observed for some quadrupole aerosol chemical speciation monitors (Q-ACSMs) which are designed for the long-term measurement of ambient aerosol composition. The ACSM reports particle concentrations based on the difference between measurements of ambient air (sample mode) and particle-free ambient air (filter mode). For our long-term campaign in Krakow, Poland, the Q-ACSM reports apparent negative total chloride concentration for most of the campaign when analyzed with the default fragmentation table. This is the result of the difference signal from m∕z 35 (35Cl+) being negative, which dominates over the positive difference signal from m∕z 36 (H35Cl+). Highly time-resolved experiments with NH4Cl, NaCl and KCl particles show that the signal response of m∕z 35 is non-ideal when the signal builds up and decreases slowly for all three salts, leading to a negative difference measurement. In contrast, the m∕z 36 signal exhibits a near step-change response for NH4Cl during the sampling and filter period, resulting in a positive difference signal. The response of m∕z 36 for NaCl and KCl is not as prompt as for NH4Cl but still fast enough to have a positive difference signal. Furthermore, it is shown that this behavior is mostly independent of vaporizer temperature. Based on these observations, this work presents an approach to correct the chloride concentration time series by adapting the standard fragmentation table coupled with a calibration of NH4Cl to obtain a relative ionization efficiency (RIE) based on the signal at m∕z 36 (H35Cl+). This correction can be applied to measurements in environments where chloride is dominated by NH4Cl. Caution should be exercised when other chloride salts dominate the ambient particulate chloride.

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Improved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)

10.5194/amt-2020-117 ◽

2020 ◽

Author(s):

Anna K. Tobler ◽

Alicja Skiba ◽

Dongyu S. Wang ◽

Philip Croteau ◽

Katarzyna Styszko ◽

...

Keyword(s):

Chemical Speciation ◽

Anthropogenic Activities ◽

Chloride Concentration ◽

Ambient Air ◽

Aerosol Composition ◽

Total Chloride ◽

Ambient Aerosol ◽

Positive Difference ◽

The Difference

Abstract. Particulate chloride is an important component of fine particulate matter in marine air masses. Recent field studies also report elevated concentrations of gas-phase reactive chlorine species and particulate chloride related to anthropogenic activities. This work focuses on particulate chloride detection and quantification issues observed for some quadrupole aerosol chemical speciation monitors (Q-ACSM), which are designed for long-term measurement of ambient aerosol composition. The ACSM reports particle concentrations based on the difference between measurements of ambient air (sample mode) and particle-free ambient air (filter mode). For our long-term campaign in Krakow, Poland, the Q-ACSM reports apparent negative total chloride concentration for most of the campaign when analyzed with the default fragmentation table. This is the result of the difference signal from m/z 35 (35Cl+) being negative which dominates over the positive difference signal from m/z 36 (H35Cl+). Highly time-resolved experiments with NH4Cl, NaCl and KCl particles show that the signal response of m/z 35 is non-ideal, where the signal builds up and decreases slowly for all three salts, leading to a negative difference measurement. In contrast, the m/z 36 signal exhibits a near step-change response for NH4Cl during sampling and filter period, resulting in a positive difference signal. The response of m/z 36 for NaCl and KCl is not as prompt as for NH4Cl but still fast enough to have a positive difference signal. Furthermore, it is shown that this behavior is mostly temperature-independent. Based on these observations, this work presents an approach to correct the chloride concentration time series by adapting the standard fragmentation table coupled with a calibration of NH4Cl to obtain a relative ionization efficiency (RIE) based on the signal at m/z 36 (H35Cl+). This correction can be applied for measurements in environments where chloride is dominated by NH4Cl. Caution should be exercised when other chloride salts dominate the ambient aerosol.

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Long-Term Ambient Air Pollutant Exposure and Risk of Recurrent Headache in Children: A 12-Year Cohort Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17239140 ◽

2020 ◽

Vol 17 (23) ◽

pp. 9140

Author(s):

Syuan-Yu Hong ◽

Lei Wan ◽

Hui-Ju Lin ◽

Cheng-Li Lin ◽

Chang-Ching Wei

Keyword(s):

Cohort Study ◽

Sulfur Dioxide ◽

Incidence Rate ◽

Air Pollutants ◽

Fine Particulate Matter ◽

Ambient Air ◽

Average Concentration ◽

Air Pollutant ◽

Research Database

Although studies have suggested environmental factors to be triggers of headache, the contribution of long-term air pollution exposure to recurrent headaches is poorly understood. Hence, we executed this nationwide cohort study to investigate associations between levels of ambient air pollutants and risks of recurrent headaches in children in Taiwan from 2000 to 2012. We used data from the Taiwan National Health Insurance Research Database and linked them to the Taiwan Air Quality Monitoring Database. Overall, 218,008 children aged < 18 were identified from 1 January 2000, and then followed until they were diagnosed by a physician for ≥3 times with recurrent headaches or until 31 December 2012. We categorized the annual average concentration of each air pollutant (fine particulate matter, total hydrocarbon, methane, sulfur dioxide, and nitrogen dioxide) into quartiles (Q1–Q4). We measured the incidence rate, hazard ratios (HRs), and the corresponding 95% confidence intervals for recurrent headaches. stratified by the quartiles. A total of 28,037 children (12.9%) were identified with recurrent headaches. The incidence rate and adjusted HR for recurrent headaches increased with higher-level exposure of air pollutants, except sulfur dioxide. We herein demonstrate that long-term ambient air pollutant exposure might be a risk factor for childhood recurrent headaches.

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The ToF-ACSM: a portable aerosol chemical speciation monitor with TOFMS detection

Atmospheric Measurement Techniques ◽

10.5194/amt-6-3225-2013 ◽

2013 ◽

Vol 6 (11) ◽

pp. 3225-3241 ◽

Cited By ~ 74

Author(s):

R. Fröhlich ◽

M. J. Cubison ◽

J. G. Slowik ◽

N. Bukowiecki ◽

A. S. H. Prévôt ◽

...

Keyword(s):

Chemical Speciation ◽

Time Of Flight ◽

Mass Resolution ◽

Remote Access ◽

Swiss Alps ◽

Scanning Mobility Particle Sizer ◽

Aerosol Composition ◽

Flight Mass Spectrometry ◽

New Instrument

Abstract. We present a new instrument for monitoring aerosol composition, the time-of-flight aerosol chemical speciation monitor (ToF-ACSM), combining precision state-of-the-art time-of-flight mass spectrometry with stability, reliability, and easy handling, which are necessities for long-term monitoring operations on the scale of months to years. Based on Aerodyne aerosol mass spectrometer (AMS) technology, the ToF-ACSM provides continuous online measurements of chemical composition and mass of non-refractory submicron aerosol particles. In contrast to the larger AMS, the compact-sized and lower-priced ToF-ACSM does not feature particle sizing, similar to the widely-used quadrupole-ACSM (Q-ACSM). Compared to the Q-ACSM, the ToF-ACSM features a better mass resolution of M/ΔM = 600 and better detection limits on the order of < 30 ng m−3 for a time resolution of 30 min. With simple upgrades these limits can be brought down by another factor of ~ 8. This allows for operation at higher time resolutions and in low concentration environments. The associated software packages (single packages for integrated operation and calibration and analysis) provide a high degree of automation and remote access, minimising the need for trained personnel on site. Intercomparisons with Q-ACSM, C-ToF-AMS, nephelometer and scanning mobility particle sizer (SMPS) measurements, performed during a first long-term deployment (> 10 months) on the Jungfraujoch mountain ridge (3580 m a.s.l.) in the Swiss Alps, agree quantitatively. Additionally, the mass resolution of the ToF-ACSM is sufficient for basic mass defect resolved peak fitting of the recorded spectra, providing a data stream not accessible to the Q-ACSM. This allows for quantification of certain hydrocarbon and oxygenated fragments (e.g. C3H7+ and C2H3O+, both occurring at m/Q = 43 Th), as well as improving inorganic/organic separation.

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The ToF-ACSM: a portable aerosol chemical speciation monitor with TOFMS detection

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-6767-2013 ◽

2013 ◽

Vol 6 (4) ◽

pp. 6767-6814 ◽

Cited By ~ 3

Author(s):

R. Fröhlich ◽

M. J. Cubison ◽

J. G. Slowik ◽

N. Bukowiecki ◽

A. S. H. Prévôt ◽

...

Keyword(s):

Chemical Speciation ◽

Time Of Flight ◽

Mass Resolution ◽

Remote Access ◽

Swiss Alps ◽

Scanning Mobility Particle Sizer ◽

Aerosol Composition ◽

Flight Mass Spectrometry ◽

New Instrument

Abstract. We present a new instrument for monitoring aerosol composition, the economy time-of-flight-aerosol chemical speciation monitor (ToF-ACSM), combining precision of state-of-the-art time-of-flight mass spectrometry with stability, reliability, and easy handling, which are necessities for long-term monitoring operations on the scale of months to years. Based on Aerodyne aerosol mass spectrometer (AMS) technology, the ToF-ACSM provides continuous online measurements of chemical composition and mass of non-refractory submicron aerosol particles. In contrast to the larger AMS, the compact-sized and lower-priced ToF-ACSM does not feature particle sizing, similar to the widely-used quadrupole-ACSM (Q-ACSM). Compared to the Q-ACSM, the ToF-ACSM features a better mass resolution of M/ΔM = 600 and better detection limits on the order of <30 ng m−3 for a time resolution of 30 min. With simple upgrades these limits can be brought down by another factor of ~8. This allows for operation at higher time resolutions and in low concentration environments. The associated software packages (single packages for integrated operation & calibration and analysis) provide a high degree of automation and remote access, minimising the need for trained personnel on site. Intercomparisons with Q-ACSM, C-ToF-AMS, nephelometer and scanning mobility particle sizer (SMPS) measurements, performed during a first long-term deployment (>6 months) on the Jungfraujoch mountain ridge (3580 m a.s.l.) in the Swiss Alps agree quantitatively. Additionally, the mass resolution of the ToF-ACSM is sufficient for basic mass defect resolved peak fitting of the recorded spectra, providing a data stream not accessible to the Q-ACSM. This allows for quantification of certain hydrocarbon and oxygenated fragments (e.g. C3H7+ and C2H3O+, both occurring at m/Q = 43 Th), as well as improving inorganic/organic separation.

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Adverse organogenesis and predisposed long-term metabolic syndrome from prenatal exposure to fine particulate matter

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1902925116 ◽

2019 ◽

pp. 201902925 ◽

Cited By ~ 6

Author(s):

Guoyao Wu ◽

Jacob Brown ◽

Misti L. Zamora ◽

Alyssa Miller ◽

M. Carey Satterfield ◽

...

Keyword(s):

Metabolic Syndrome ◽

Particulate Matter ◽

Fine Particulate Matter ◽

Adult Life ◽

Ambient Air ◽

Postnatal Growth ◽

Female Rats ◽

Gestation Length ◽

Fine Particulate

Exposure to fine particulate matter (PM) during pregnancy is associated with high risks of birth defects/fatality and adverse long-term postnatal health. However, limited mechanistic data are available to assess the detailed impacts of prenatal PM exposure. Here we evaluate fine PM exposure during pregnancy on prenatal/postnatal organogenesis in offspring and in predisposing metabolic syndrome for adult life. Between days 0 and 18 of gestation, two groups of adult female rats (n = 10 for each) were placed in a dual-exposure chamber device, one with clean ambient air (∼3 µg·m−3) and the other with ambient air in the presence of 100 to 200 µg·m−3 of ultrafine aerosols of ammonium sulfate. At birth (postnatal day 0, PND0), four males and four females were selected randomly from each litter to be nursed by dams, whereas tissues were collected from the remaining pups. At PND21, tissues were collected from two males and two females, whereas the remaining pups were fed either a high- or low-fat diet until PND105, when tissues were obtained for biochemical and physiological analyses. Maternal exposure to fine PM increased stillbirths; reduced gestation length and birth weight; increased concentrations of glucose and free fatty acids in plasma; enhanced lipid accumulation in the liver; and decreased endothelium-dependent relaxation of aorta. This lead to altered organogenesis and predisposed progeny to long-term metabolic defects in an age-, organ-, and sex-specific manner. Our results highlight the necessity to develop therapeutic strategies to remedy adverse health effects of maternal PM exposure on conceptus/postnatal growth and development.

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The Expression of Surface Chloride Concentration in Ecological Concrete and Service Life Prediction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.368-373.2204 ◽

2011 ◽

Vol 368-373 ◽

pp. 2204-2210 ◽

Cited By ~ 1

Author(s):

Si Feng Liu

Keyword(s):

Fly Ash ◽

Service Life ◽

Life Prediction ◽

Chloride Concentration ◽

Total Chloride ◽

One Dimensional ◽

Dimensional Diffusion ◽

Diffusion Depth ◽

Chloride Concentrations

The total chloride concentrations of concrete with 0.51 of water to cementitous from three contents of Fly ash, GGBS, two kinds of corrosion solution for one dimensional diffusion at different diffusion depth and time were measured by chemical titration. The influence of Fly ash and GGBS content on total chloride concentration and the surface chloride concentration were analyzed. The expressions of the surface chloride concentration were discussed in terms of the experimental results related with content of Fly ash, GGBS and solution. The numerical analysis results indicated that the expression of the surface chloride concentration has a significant impact on the long-term service life of concrete in chloride environments.

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Long-term steady state <sup>13</sup>C labelling to investigate carbon turnover in plant soil systems

Biogeosciences Discussions ◽

10.5194/bgd-4-797-2007 ◽

2007 ◽

Vol 4 (2) ◽

pp. 797-821 ◽

Cited By ~ 2

Author(s):

K. Klumpp ◽

J. F. Soussana ◽

R. Falcimagne

Keyword(s):

Steady State ◽

Urban Areas ◽

Co2 Concentration ◽

Ambient Air ◽

Organic C ◽

Plant Soil ◽

Soil Systems ◽

The Mean ◽

The Difference

Abstract. We have set up a facility allowing steady state 13CO2 labeling of short stature vegetation (12 m2) for several years. 13C labelling is obtained by scrubbing the CO2 from outdoors air with a self-regenerating molecular sieve and by replacing it with 13C depleted (−34.7±0.03‰) fossil-fuel derived CO2 The facility, which comprises 16 replicate mesocosms, allows tracing the fate of photosynthetic carbon in plant-soil systems in natural light and at outdoors temperature. This method was applied during 2 yrs to temperate grassland monoliths (0.5×0.5×0.4 m) sampled in a long term grazing experiment. During daytime, the canopy enclosure in each mesocosm was supplied in an open flow (0.67–0.88 volume per minute) with modified air (43% scrubbed air and 57% cooled and humidified ambient air) at mean CO2 concentration of 425 µmol mol−1 and δ13C of −21.5±0.27‰. Above and belowground CO2 fluxes were continuously monitored. The difference in δ13C between the CO2 at the outlet and at the inlet of each canopy enclosure was not significant (−0.35±0.39‰). Due to mixing with outdoors air, the CO2 concentration at enclosure inlet followed a seasonal cycle, often found in urban areas, where δ13C of CO2 is lower in winter than in summer. Mature C3 grass leaves were sampled monthly in each mesocosm, as well as leave from pot-grown control C4 (Paspalum dilatatum). The mean δ13C of fully labelled C3 and C4 leaves reached −41.4±0.67 and −28.7±0.39‰ respectively. On average, the labelling reduced by 12.7‰ the δ13C of C3 grass leaves. The isotope mass balance technique was used to calculate the fraction of "new" C in the soil organic matter (SOM) above 0.2 mm. A first order exponential decay model fitted to "old" C data showed that reducing aboveground disturbance by cutting increased from 22 to 31 months the mean residence time of belowground organic C (>0.2 mm) in the top soil.

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Racial Difference in the Association of Long-Term Exposure to Fine Particulate Matter (PM2.5) and Cardiovascular Disease Mortality among Renal Transplant Recipients

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18084297 ◽

2021 ◽

Vol 18 (8) ◽

pp. 4297

Author(s):

Salem Dehom ◽

Synnove Knutsen ◽

Khaled Bahjri ◽

David Shavlik ◽

Keiji Oda ◽

...

Keyword(s):

Cardiovascular Disease ◽

Renal Transplant ◽

Racial Differences ◽

Cox Regression ◽

Fine Particulate Matter ◽

Ambient Air ◽

Renal Transplant Recipients ◽

Transplant Recipients ◽

Increased Risk

Ambient air pollutants are known risk factors for cardiovascular disease (CVD) morbidity and mortality with significant racial disparities. However, few studies have explored racial differences among highly susceptible subpopulations, such as renal transplant recipients (RTRs). Despite improvements in quality of life after transplantation, CVD remains the major cause of mortality, especially among Black recipients. This study aimed to evaluate potential racial differences in the association between long-term levels of PM2.5 and the risk of all-cause, total CVD, and coronary heart disease (CHD) mortality among RTRs. This retrospective study consists of 93,857 non-smoking adults who received a renal transplant between 2001 and 2015. Time-dependent Cox regression was used to assess the association between annual concentrations of PM2.5 and mortality risk. In the multivariable-adjusted models, a 10 μg/m3 increase in ambient PM2.5 levels found increased risk of all-cause (HR = 3.45, 95% CI: 3.08–3.78), CVD (HR = 2.38, 95% CI: 1.94–2.92), and CHD mortality (HR = 3.10, 95% CI: 1.96–4.90). Black recipients had higher risks of all-cause (HR = 4.09, 95% CI: 3.43–4.88) and CHD mortality (HR = 6.73, 95% CI: 2.96–15.32). High levels of ambient PM2.5 were associated with all-cause, CVD, and CHD mortality. The association tended to be higher among Black recipients than non-Blacks.

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