Abstract
Volatile arsenic compounds in natural gas, existing in the form of trimethylarsine (TMAs), have been determined using gas cryo-trapping gas chromatography coupled to inductively coupled plasma-mass spectrometry (CT-GC-ICP-MS). The results from a number of different gas wells revealed a huge concentration spread ranging from below the detection limit of 0.2 up to 1800 mu g/m(3) TMAs (as As) in the gas. Due to the toxicity and corrosive nature of these arsines, they need near real time monitoring via a method that can easily be implemented on site, i.e. during gas exploitation. Here, we introduce a novel method which utilises silver nitrate impregnated silica gel tubes for quantitative chemotrapping of trimethylarsine (TMAs) from a natural gas matrix. Subsequent elution with hot nitric acid followed by online photo-oxidation hydride generation atomic fluorescence spectrometry (HG-AFS) is used for the determination of TMAs gas standards in nitrogen and natural gas samples, respectively. The chemotrapping method was validated using CT-GC-ICP-MS as a reference method. The recovery of arsenic from nitrogen or natural gas matrix ranged from 85 to 113% for a range of 20 to 2000 ng As. Trapping efficiency was > 98%, from the methods LOD of 20 ng to 4.8 mu g (absolute amount As) with sample sizes of 0.02 and 2 L gas. Method performance was established by comparing the results obtained for eight natural gas samples containing between 1 and 140 mu g As/m(3) with those achieved by the reference method (CT-GC-ICP-MS).
| Original language | English |
|---|---|
| Pages (from-to) | 2222-2230 |
| Number of pages | 9 |
| Journal | Journal of Environmental Monitoring |
| Volume | 11 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 2009 |
Keywords
- trimethylarsine
- speciation
- chromatography
Cite this
Chemotrapping-atomic fluorescence spectrometric method as a field method for volatile arsenic in natural gas. / Uroic, Miran Kalle; Krupp, Eva Maria; Johnson, Charlie; Feldmann, Jorg.
In: Journal of Environmental Monitoring, Vol. 11, No. 12, 2009, p. 2222-2230.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Chemotrapping-atomic fluorescence spectrometric method as a field method for volatile arsenic in natural gas
AU - Uroic, Miran Kalle
AU - Krupp, Eva Maria
AU - Johnson, Charlie
AU - Feldmann, Jorg
PY - 2009
Y1 - 2009
N2 - Volatile arsenic compounds in natural gas, existing in the form of trimethylarsine (TMAs), have been determined using gas cryo-trapping gas chromatography coupled to inductively coupled plasma-mass spectrometry (CT-GC-ICP-MS). The results from a number of different gas wells revealed a huge concentration spread ranging from below the detection limit of 0.2 up to 1800 mu g/m(3) TMAs (as As) in the gas. Due to the toxicity and corrosive nature of these arsines, they need near real time monitoring via a method that can easily be implemented on site, i.e. during gas exploitation. Here, we introduce a novel method which utilises silver nitrate impregnated silica gel tubes for quantitative chemotrapping of trimethylarsine (TMAs) from a natural gas matrix. Subsequent elution with hot nitric acid followed by online photo-oxidation hydride generation atomic fluorescence spectrometry (HG-AFS) is used for the determination of TMAs gas standards in nitrogen and natural gas samples, respectively. The chemotrapping method was validated using CT-GC-ICP-MS as a reference method. The recovery of arsenic from nitrogen or natural gas matrix ranged from 85 to 113% for a range of 20 to 2000 ng As. Trapping efficiency was > 98%, from the methods LOD of 20 ng to 4.8 mu g (absolute amount As) with sample sizes of 0.02 and 2 L gas. Method performance was established by comparing the results obtained for eight natural gas samples containing between 1 and 140 mu g As/m(3) with those achieved by the reference method (CT-GC-ICP-MS).
AB - Volatile arsenic compounds in natural gas, existing in the form of trimethylarsine (TMAs), have been determined using gas cryo-trapping gas chromatography coupled to inductively coupled plasma-mass spectrometry (CT-GC-ICP-MS). The results from a number of different gas wells revealed a huge concentration spread ranging from below the detection limit of 0.2 up to 1800 mu g/m(3) TMAs (as As) in the gas. Due to the toxicity and corrosive nature of these arsines, they need near real time monitoring via a method that can easily be implemented on site, i.e. during gas exploitation. Here, we introduce a novel method which utilises silver nitrate impregnated silica gel tubes for quantitative chemotrapping of trimethylarsine (TMAs) from a natural gas matrix. Subsequent elution with hot nitric acid followed by online photo-oxidation hydride generation atomic fluorescence spectrometry (HG-AFS) is used for the determination of TMAs gas standards in nitrogen and natural gas samples, respectively. The chemotrapping method was validated using CT-GC-ICP-MS as a reference method. The recovery of arsenic from nitrogen or natural gas matrix ranged from 85 to 113% for a range of 20 to 2000 ng As. Trapping efficiency was > 98%, from the methods LOD of 20 ng to 4.8 mu g (absolute amount As) with sample sizes of 0.02 and 2 L gas. Method performance was established by comparing the results obtained for eight natural gas samples containing between 1 and 140 mu g As/m(3) with those achieved by the reference method (CT-GC-ICP-MS).
KW - trimethylarsine
KW - speciation
KW - chromatography
U2 - 10.1039/b913322d
DO - 10.1039/b913322d
M3 - Article
VL - 11
SP - 2222
EP - 2230
JO - Journal of Environmental Monitoring
JF - Journal of Environmental Monitoring
SN - 1464-0325
IS - 12
ER -