NIST gas standards containing volatile organic compounds in support of ambient air pollution measurements

Air pollution is one of the primary sources of risk to human health in the world. In this study, seasonal and spatial variations of multiple volatile organic compounds (VOCs) were measured at six sampling sites in Almaty, Kazakhstan. The seasonal and spatial variations of 19 VOCs were evaluated in 2020, including the periods before and after COVID-19 lockdown. The concentrations of 9 out of 19 VOCs had been changed significantly (p < 0.01) during 2020. The maximum concentrations of total VOCs (TVOCs) were observed on 15, 17, and 19 January and ranged from 233 to 420 µg m−3. The spatial distribution of TVOCs concentrations in the air during sampling seasons correlated with the elevation and increased from southern to northern part of Almaty, where Combined Heat and Power Plants are located. The sources of air pollution by VOCs were studied by correlations analysis and BTEX ratios. The ranges of toluene to benzene ratio and benzene, toluene, and ethylbenzene demonstrated two primary sources of BTEX in 2020: traffic emissions and biomass/biofuel/coal burning. Most of m-, p-xylenes to ethylbenzene ratios in this study were lower than 3 in all sampling periods, evidencing the presence of aged air masses at studied sampling sites from remote sources.

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Monitoring of volatile organic compounds in ambient air of Taldykorgan, Kazakhstan

Chemical Bulletin of Kazakh National University ◽

10.15328/cb1095 ◽

2019 ◽

pp. 4-12

Author(s):

Lyazzat Serik ◽

Olga Ibragimova ◽

Gulim Ussenova ◽

Nassiba Baimatova

Keyword(s):

Air Pollution ◽

Volatile Organic Compounds ◽

Organic Compounds ◽

Solid Phase Microextraction ◽

Solid Phase ◽

Ambient Air ◽

Volatile Organic ◽

The World ◽

Benzene Toluene ◽

Almost All

The pollution of ambient air is one of the main sources of risk to human health in the world. There is a direct relationship between the level of air pollution and risk of the development of cancer, cardiovascular, respiratory and other diseases. Benzene, toluene, ethylbenzene and o-xylene (BTEX) are one of the most toxic volatile organic compounds. The aim of this study was to quantify BTEX in air of Taldykorgan, Kazakhstan using solid-phase microextraction followed by gas chromatography with mass-spectrometric detection. In different sampling seasons, average concentrations of four BTEX analytes varied from 7.5 to 27 µg/m3, from 15 to 250 µg/m3, from 2.4 to 12.8 µg/m3 and from 2.6 to 21 µg/m3, respectively. The highest concentrations of TEX were detected in autumn, while the highest concentrations of benzene were observed in winter. Toluene-to-benzene ratios in almost all measurements were above 1 indicating that the traffic emissions are the main source of air pollution with BTEX.

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A Comparison Study of Sampling and Analyzing Volatile Organic Compounds in Air in Kuwait by Using Tedlar Bags/Canisters and GC-MS with a Cryogenic Trap

The Scientific World JOURNAL ◽

10.1100/tsw.2006.111 ◽

2006 ◽

Vol 6 ◽

pp. 551-562

Author(s):

Hongmao Tang ◽

Khaliq R. Beg ◽

Yousef Al-Otaiba

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Internal Standard ◽

Ambient Air ◽

Sample Container ◽

Air Samples ◽

Study Results ◽

Volatile Organic ◽

Dry Conditions ◽

Gas Standards

Kuwait experiences desert climatic weather. Due to the extreme hot and dry conditions in this country, some analytical phenomena have been discovered. Therefore, a systematic study of sampling and analyzing volatile organic compounds in air by using GC-MS with a cryogenic trap is reported in this paper. This study included comparisons of using different sample containers such as Tedlar bags and SUMMA canisters, and different cryogenic freezing-out air volumes in the trap. Calibration curves for different compounds and improvement of replicated analysis results were also reported here. The study found that using different sample containers produced different results. Analysis of ambient air samples collected in Tedlar bags obtained several volatile organic compounds with large concentrations compared to using SUMMA canisters. Therefore, to choose a sample container properly is a key element for successfully completing a project. Because GC-MS with a cryogenic trap often generates replicated results with poor agreement, an internal standard added to gas standards and air samples by using a gas syringe was tested. The study results proved that it helped to improve the replicated results.

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