Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric PM

Abstract. A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter (PM) is presented. It has been found in numerous laboratory studies that these compounds are photooxidation products of toluene in PM. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. PM was collected on quartz fibre filters using dichotomous high volume air samplers for PM 2.5. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography (HPLC) and solid phase extraction (SPE). The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyl)trifluoroacetamide (BSTFA), was added to the solution for Gas Chromatography/Mass Spectroscopy (GC/MS) analysis. The second half of the sample was stored at low temperature. When GC/MS analysis showed high enough concentrations the remaining sample was derivatized with BSTFA and analysed for stable isotope ratio using a Gas Chromatography/Isotope Ratio Mass Spectrometry (GC-IRMS). In all atmospheric PM samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol. Nevertheless, due to low pollution levels occurring in the rural area, no samples had concentrations high enough to perform stable carbon isotope composition measurements of the methylnitrophenols. Samples collected in the suburban area could be analysed for carbon stable isotope ratio using GC-IRMS. The procedure described in this paper provides a very sensitive and selective method for the analysis of methylnitrophenols in atmospheric PM at concentrations as low as 1 pg m−3. For accurate (within ±0.5‰) stable isotope ratio analysis significantly higher concentrations in the range of 100 pg m−3 or more are required.

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Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric particulate matter

Atmospheric Measurement Techniques ◽

10.5194/amt-4-2453-2011 ◽

2011 ◽

Vol 4 (11) ◽

pp. 2453-2464 ◽

Cited By ~ 11

Author(s):

S. Moukhtar ◽

M. Saccon ◽

A. Kornilova ◽

S. Irei ◽

L. Huang ◽

...

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Particulate Matter ◽

Stable Isotope ◽

Carbon Isotope ◽

Isotope Ratio ◽

Stable Carbon Isotope ◽

Atmospheric Particulate Matter ◽

Stable Carbon ◽

Atmospheric Particulate

Abstract. A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter is presented. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. Particulate matter was collected on quartz fibre filters using dichotomous high volume air samplers. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography and solid phase extraction. The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyl)trifluoroacetamide, was added for Gas Chromatography-Mass Spectrometry analysis. The second half of the sample was stored in a refrigerator. For samples with concentrations exceeding 1 ng μl−1, the second half of the sample was used for measurement of stable carbon isotope ratios by Gas Chromatography-Isotope Ratio Mass Spectrometry. The procedure described in this paper provides a method for the analysis of methylnitrophenols in atmospheric particulate matter at concentrations as low as 0.3 pg m−3 and for stable isotope ratios with an accuracy of better than ±0.5‰ for concentrations exceeding 100 pg m−3. In all atmospheric particulate matter samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol, with concentrations ranging from the low pg m−3 range in rural areas to more than 200 pg m−3 in some samples from a suburban location.

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Mechanism of anaerobic biological activated carbon process examined by using stable isotope

Water Science & Technology ◽

10.2166/wst.1996.0579 ◽

1996 ◽

Vol 34 (5-6) ◽

pp. 429-435 ◽

Cited By ~ 1

Author(s):

Toshiaki Saito ◽

Keisuke Hanaki ◽

Tomonori Matsuo

Keyword(s):

Activated Carbon ◽

Stable Isotope ◽

Carbon Isotope ◽

Isotope Ratio ◽

Stable Carbon Isotope ◽

The Other ◽

Bulk Liquid ◽

Stable Carbon ◽

Biological Activated Carbon ◽

Attached Bacteria

This research focused on the mechanism of substrate transfer in anaerobic biological activated carbon (BAC) process. There are two possible pathways of substrate supply to the attached bacteria in BAC process. One is the pathway from the bulk liquid and the other is the pathway directly from activated carbon. Stable carbon isotope was used to determine them. The isotope ratio of produced methane was between isotope ratios in bulk liquid and inside activated carbon. This means that activated carbon can supply adsorbed substances directly to the attached bacteria without releasing them into bulk liquid.

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