scholarly journals An inter-laboratory comparison of aerosol in organic ion measurements by Ion Chromatography: implications for aerosol pH estimate

2020 ◽  
Author(s):  
Jingsha Xu ◽  
Shaojie Song ◽  
Roy M. Harrison ◽  
Congbo Song ◽  
Lianfang Wei ◽  
...  
Keyword(s):  
Major Ions ◽  
Certified Reference Materials ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Ion Concentrations ◽  
Inorganic Ion ◽  
Aerosol Acidity ◽  
Water Soluble Inorganic Ions ◽  
Good Agreement

Abstract. Water soluble inorganic ions such as ammonium, nitrate, and sulfate are major components of fine aerosols in the atmosphere and are widely used in the estimation of aerosol acidity. However, different experimental practices and instrumentation may lead to uncertainties in ion concentrations. Here, an inter-comparison experiment was conducted in 10 different laboratories (labs) to investigate the consistency of inorganic ion concentrations and resultant aerosol acidity estimates using the same set of aerosol filter samples. The results mostly exhibited good agreement for major ions Cl−, SO42−, NO3−, NH4+ and K+. However, F−, Mg2+ and Ca2+ were observed with more variations across the different labs. The Aerosol Chemical Speciation Monitor (ACSM) data of non-refractory SO42−, NO3−, NH4+ generally correlated very well with the filter analysis based data in our study, but the absolute concentrations differ by up to 42 %. Cl− from the two methods are correlated but the concentration differ by more than 3 times. The analyses of certified reference materials (CRMs) generally showed good recovery of all ions in all the labs, the majority of which ranged between 90 % and 110 %. Better agreements were found for Cl−, SO42−, NO3−, NH4+ and K+ across the labs after their concentrations were corrected with CRM recoveries; the coefficient of variation (CV) of Cl−, SO42−, NO3−, NH4+ and K+ decreased 1.7 %, 3.4 %, 3.4 %, 1.2 % and 2.6 %, respectively, after CRM correction. We found that the ratio of anion to cation equivalent concentrations (AE/CE) is not a good indicator for aerosol acidity estimates, as the results in different labs did not agree well with each other. Ion balance (anions – cations) calculated from SO42−, NO3− and NH4+ gave more consistent results, because of their relatively large concentrations and good agreement among different labs. In situ aerosol pH calculated from the ISORROPIA-II thermodynamic equilibrium model with measured ion and ammonia concentrations showed a similar trend and good agreement across the 10 labs. Our results indicate that although there are important uncertainties in aerosol ion concentration measurements, the estimated aerosol pH from the ISORROPIA-II model is more consistent.

scholarly journals An interlaboratory comparison of aerosol inorganic ion measurements by ion chromatography: implications for aerosol pH estimate

2020 ◽  
Vol 13 (11) ◽  
pp. 6325-6341
Author(s):  
Jingsha Xu ◽  
Shaojie Song ◽  
Roy M. Harrison ◽  
Congbo Song ◽  
Lianfang Wei ◽  
...  
Keyword(s):  
Major Ions ◽  
Certified Reference Materials ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Detection Accuracy ◽  
Ion Concentrations ◽  
Inorganic Ion ◽  
Aerosol Acidity ◽  
Good Agreement

Abstract. Water-soluble inorganic ions such as ammonium, nitrate and sulfate are major components of fine aerosols in the atmosphere and are widely used in the estimation of aerosol acidity. However, different experimental practices and instrumentation may lead to uncertainties in ion concentrations. Here, an intercomparison experiment was conducted in 10 different laboratories (labs) to investigate the consistency of inorganic ion concentrations and resultant aerosol acidity estimates using the same set of aerosol filter samples. The results mostly exhibited good agreement for major ions Cl−, SO42-, NO3-, NH4+ and K+. However, F−, Mg2+ and Ca2+ were observed with more variations across the different labs. The Aerosol Chemical Speciation Monitor (ACSM) data of nonrefractory SO42-, NO3- and NH4+ generally correlated very well with the filter-analysis-based data in our study, but the absolute concentrations differ by up to 42 %. Cl− from the two methods are correlated, but the concentration differ by more than a factor of 3. The analyses of certified reference materials (CRMs) generally showed a good detection accuracy (DA) of all ions in all the labs, the majority of which ranged between 90 % and 110 %. The DA was also used to correct the ion concentrations to showcase the importance of using CRMs for calibration check and quality control. Better agreements were found for Cl−, SO42-, NO3-, NH4+ and K+ across the labs after their concentrations were corrected with DA; the coefficient of variation (CV) of Cl−, SO42-, NO3-, NH4+ and K+ decreased by 1.7 %, 3.4 %, 3.4 %, 1.2 % and 2.6 %, respectively, after DA correction. We found that the ratio of anion to cation equivalent concentrations (AE / CE) and ion balance (anions–cations) are not good indicators for aerosol acidity estimates, as the results in different labs did not agree well with each other. In situ aerosol pH calculated from the ISORROPIA II thermodynamic equilibrium model with measured ion and ammonia concentrations showed a similar trend and good agreement across the 10 labs. Our results indicate that although there are important uncertainties in aerosol ion concentration measurements, the estimated aerosol pH from the ISORROPIA II model is more consistent.

scholarly journals CHEMICAL COMPOSITION OF AEROSOLS IN THE WEST COAST OF TAIWAN STRAIT, CHINA

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 233-237
Author(s):  
L. Zhao ◽  
C. Yang
Keyword(s):  
Chemical Composition ◽  
Mass Spectrometer ◽  
Single Particle ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Aerosol Mass Spectrometer ◽  
Average Mass ◽  
Inorganic Ion ◽  
Aerosol Mass

Abstract. The chemical composition of aerosols was investigated using regular environmental air quality observation, a single particle aerosol mass spectrometer (SPAMS 0515) and an ambient ion monitor (URG 9000D) in Xiamen in 2018. The results showed that the annual average mass concentrations of PM2.5 was 22 μm/m3, and concentrations of water-soluble inorganic ions was 9.94 μm/m3 which accounted for 45.2% of PM2.5. SO42−, NO3− and NH4+ were main components of secondary reactions which contributed more than 77 percent of water-soluble inorganic ion concentration. As a coastal city, Cl− and Na+ contributed 13.9 percent of water-soluble inorganic ion concentration. Based on single particle aerosol mass spectrometer analysing, mobile sources emission was the most important sources of particle matter which contributed over 30%.

scholarly journals Characterization of Atmospheric PM2.5 Inorganic Aerosols Using the Semi-Continuous PPWD-PILS-IC System and the ISORROPIA-II

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 820
Author(s):  
Thi-Cuc Le ◽  
Yun-Chin Wang ◽  
David Y. H. Pui ◽  
Chuen-Jinn Tsai
Keyword(s):  
Thermodynamic Equilibrium ◽  
Equilibrium Model ◽  
Inorganic Ions ◽  
Porous Metal ◽  
Water Soluble ◽  
Inorganic Aerosols ◽  
Daily Data ◽  
Water Soluble Inorganic Ions ◽  
Thermodynamic Equilibrium Model ◽  
Good Agreement

A semi-continuous monitoring system, a parallel plate wet denuder and particle into liquid sampler coupled with ion chromatography (PPWD-PILS-IC), was used to measure the hourly precursor gases and water-soluble inorganic ions in ambient particles smaller than 2.5 µm in diameter (PM2.5) for investigating the thermodynamic equilibrium of aerosols using the ISORROPIA-II thermodynamic equilibrium model. The 24-h average PPWD-PILS-IC data showed very good agreement with the daily data of the manual 5 L/min porous-metal denuder sampler with R2 ranging from 0.88 to 0.98 for inorganic ions (NH4+, Na+, K+, NO3−, SO42−, and Cl−) and 0.89 to 0.98 for precursor gases (NH3, HNO3, HONO, and SO2) and slopes ranging from 0.94 to 1.17 for ions and 0.87 to 0.95 for gases, respectively. In addition, the predicted ISORROPIA-II results were in good agreement with the hourly observed data of the PPWD-PILS-IC system for SO42− (R2 = 0.99 and slope = 1.0) and NH3 (R2 = 0.97 and slope = 1.02). The correlation of the predicted results and observed data was further improved for NH4+ and NO3− with the slope increasing from 0.90 to 0.96 and 0.95 to 1.09, respectively when the HNO2 and NO2− were included in the total nitrate concentration (TN = [NO3−] + [HNO3] + [HONO] + [NO2−]). The predicted HNO3 data were comparable to the sum of the observed [HNO3] and [HONO] indicating that HONO played an important role in the thermodynamic equilibrium of ambient PM2.5 aerosols but has not been considered in the ISORROPIA-II thermodynamic equilibrium model.

Characteristics of Ion Concentration in the Atmospheric Particles in Harbin

2010 ◽  
Vol 113-116 ◽  
pp. 1439-1442
Author(s):  
Kun Wang ◽  
Hui Ling Duan ◽  
Li Kun Huang ◽  
Wen Shuai Wang
Keyword(s):  
Particulate Matter ◽  
Emission Spectroscopy ◽  
Inorganic Ions ◽  
Atomic Emission ◽  
Water Soluble ◽  
Atmospheric Particulate Matter ◽  
Ion Concentration ◽  
Plasma Atomic Emission ◽  
Atmospheric Particle ◽  
Water Soluble Inorganic Ions

We analyzed characteristics and concentrations of water-soluble inorganic ions based on fixed routine collection of atmospheric particulate matter (PM10, PM2.5) samples in Harbin during August 2008 and May 2009. The samplers we sampling is produced by Wuhan Tianhong Intelligent Instrument, we analyzed the water-soluble inorganic ions by using Ion Chromatographic (IC, DX120, Diana, USA) and Indicative Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES, Model 5300, Perkin Elmer, USA). The research showed that: SO42-, NO3-, NH4+ were the top three concentrated of the water-soluble inorganic ions ,the average concentrations were 10.3 μg/m3, 5.8 μg/m3, 8.2 μg/m3 respectively during sampling. Ca2+ was higher in the particulate > 2.5μm, while SO42- and NH4+ were higher in the particulate < 2.5μm, the correlation analysis inferred that the main form of SO42- in atmospheric particle was ammonium sulfate.

Water-soluble inorganic ions of size-differentiated atmospheric particles from a suburban site of Mexico City

2017 ◽  
Vol 75 (2) ◽  
pp. 155-169 ◽  
Author(s):  
Telma Castro ◽  
Oscar Peralta ◽  
Dara Salcedo ◽  
José Santos ◽  
María I. Saavedra ◽  
...  
Keyword(s):  
Mexico City ◽  
Inorganic Ions ◽  
Atmospheric Particles ◽  
Water Soluble ◽  
Water Soluble Inorganic Ions ◽  
Suburban Site

scholarly journals The sensitivity of PM<sub>2.5</sub> acidity to meteorological parameters and chemical composition changes: 10-year records from six Canadian monitoring sites

2019 ◽  
Author(s):  
Ye Tao ◽  
Jennifer G. Murphy
Keyword(s):  
Chemical Composition ◽  
Meteorological Parameters ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Seasonal Cycles ◽  
Accuracy And Precision ◽  
Different Seasons ◽  
Water Soluble Inorganic Ions ◽  
Composition Changes

Abstract. Aerosol pH is difficult to measure directly but can be calculated if the chemical composition is known with sufficient accuracy and precision to calculate the aerosol water content and the H+ concentration through ion balance. In practical terms, simultaneous measurements of at least one semi-volatile constitute, e.g. NH3 or HNO3, are required to provide a constraint on the calculation of pH. Long-term records of aerosol pH are scarce due to the limited monitoring of NH3 in conjunction with PM2.5. In this study, 10-year (2007–2016) records of pH of PM2.5 at six eastern Canadian sites were calculated using the E-AIM II model with the input of gaseous NH3, gaseous HNO3 and major water-soluble inorganic ions in PM2.5 provided by Canada's National Air Pollution Surveillance (NAPS) Program. Clear seasonal cycles of aerosol pH were found with lower pH (~2) in summer and higher pH (~3) in winter consistently across all six sites, while the day-to-day variations of aerosol pH were higher in winter compared to summer. Tests of the sensitivity of aerosol pH to meteorological parameters demonstrate that the changes in ambient temperature largely drive the seasonal cycle of aerosol pH. The sensitivity of pH to chemical composition shows that pH has different responses to the changes in chemical composition in different seasons. During summertime, aerosol pH was mainly determined by temperature with limited impact from changes in NHx or sulfate concentrations. However, in wintertime, both meteorological parameters and chemical composition contribute to the variations in aerosol pH, resulting in the larger variation during wintertime. This study reveals that the sensitivity of aerosol pH to chemical composition is distinctly different under different meteorological conditions and needs to be carefully examined for any particular region.

Effect of Inorganic Ions on Biofilms Component and Activity in the Recirculating Cooling Water System

2012 ◽  
Vol 512-515 ◽  
pp. 2287-2290
Author(s):  
Fang Liu ◽  
Fei Yang Wang ◽  
Chang Feng Liang ◽  
Wen Wen Dong ◽  
Jia Quan Zhang ◽  
...  
Keyword(s):  
Dehydrogenase Activity ◽  
Extracellular Polymeric Substances ◽  
Water System ◽  
Cooling Water ◽  
Inorganic Ions ◽  
Laboratory Model ◽  
Obvious Effect ◽  
Ion Concentrations ◽  
Inorganic Ion ◽  
Cooling Water System

In this research a laboratory model recirculating cooling water system was applied to investigate the effects of four kinds of inorganic ion concentrations on extracellular polymeric substances (EPS) content, the ration of proteins and polysaccharides ratio in EPS (PR/PS) and dehydrogenase activity (DHA) in the attached biofilms. The results showed that the low Na+ concentration was beneficial to EPS production and biofilms DHA. With Ca2+ concentration increasing, EPS content first increased and then decreased as a whole. Mg2+ showed no obvious effect on biofilms EPS content, while had the effect on PR/PS and DHA. The increase of Fe3+ concentration was beneficial for EPS formation and DHA when Fe3+ concentration was below 1.5 mg/L.

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