Evaluation of various solid adsorbents for sampling trace levels of methanethiol

doi:10.1016/S0146-6380(96)00117-9

Organic Geochemistry

Volume 24, Issues 8–9, August–September 1996, Pages 941-944

https://doi.org/10.1016/S0146-6380(96)00117-9 Get rights and content

Abstract

The efficiency of fourteen solid adsorbent sampling tubes in trapping trace levels of methanethiol was evaluated. A thermal desorption-gas chromatographic method for the accurate separation of methanethiol from other simultaneously collected reduced volatile sulfur gases was developed. Trapping experiments demonstrated that silica gel (96.4% recovery) and molecular sieves (86.2% recovery) were the best solid adsorbent materials for collecting methanethiol when the sweep gas is dry. Using a calcium chloride drying tube, silica gel provided similar results (i.e., better than 95% recovery values) when the sweep gas contained moisture (i.e., normal field sampling conditions). Molecular sieves also were shown to be acceptable adsorbent materials for trapping methanethiol under moist conditions (73.9% recovery). Recovery values showed no significant changes during 36 h storage or using different flow rates (between 10–80 ml/min).

References (28)

H. Berresheim
Distribution of atmospheric sulfur species over various wetland regions in the southeastern U.S.A.
Atmos. Environ.
(1993)
H. Berresheim et al.
Vertical distributions of COS, CS₂, DMS and other sulfur compounds in a loblolly pine forest
Atmos. Environ.
(1992)
X. Cao et al.
Thermal desorption efficiencies for different adsorbate/adsorbent systems typically used in air monitoring programmes
Chemosphere
(1993)
K.S. Cho et al.
Enhanced removability of odorous sulfur-containing gases by mixed cultures of purified bacteria from peat biofilters
J. Ferment. Bioeng.
(1992)
D.J. Cooper et al.
Short-term variability in biogenic sulphur emission from a Florida Spartina alterniflora marsh
Atmos. Environ.
(1987)
M.C. Morrison et al.
The variability of biogenic sulfur flux from a temperate salt marsh on short time and space scales
Atmos. Environ.
(1990)
S.J. Park et al.
Treatment of exhaust-gases from a night soil treatment-plant by a combined deodorization system of activated carbon fabric reactor and peat biofilter inoculated with Thiobacilus-Thioparus DW44
J. Ferment. Bioeng.
(1993)
A. Vairavamurthy et al.
Methods for determination of low molecular weight carbonyl compounds in the atmosphere: a review
Atmos. Environ.
(1992)
D.F. Adams et al.
Biogenic sulfur source strengths
Env. Sci. Technol.
(1981)
T. Alkanani et al.
Odor control in liquid hog manure by added amandments and aeration
J. Environ. Qual.
(1992)

M.S. Black et al.

Solid adsorbent preconcentration and gas chromatographic analysis of sulfur gases

Anal. Chem.

(1978)

H.W. Chin et al.

Volatile sulfur-compounds formed in disrupted tissues of different cabbage cultivars

J. Food Sci.

(1993)

I. Devai et al.

Trapping efficiency of various solid adsorbents for sampling and quantitative gas chromatographic analysis of carbonyl sulfide

Analytical Letters

(1997)

I. Devai et al.

Effect of different drying tubes on the reduced sulfur gas content of the sweep air

Acta Biol. Debr. Oecol. Hung.

(1996)

Cited by (19)

Characterization of biogas and biomethane trace compounds: A critical review of advances in in situ sampling and preconcentration techniques
2022, Analytica Chimica Acta
Worldwide, the valorization of biogas, landfill gas and biomethane is gaining momentum as circular economies and energy transitions are triggered. Nevertheless, to sustainably integrate those gases into today's energy mix, their quality must be controlled regarding their major, minor and trace constituents to preserve the integrity of infrastructures wherein they are burned, transported or stored. Field gas sampling is the first and most critical step in the analytical chain to characterize the composition of such gases. A large array of gas sampling techniques is available, yet choosing the most suitable technique is complex, especially when targeting trace compounds (<ng·Nm⁻³ to mg·Nm⁻³) which often require a preconcentration step to be detectable. Sampled trace compounds must be kept stable (no loss, degradation or contamination can occur) during the storage phase between sampling and analysis, and all materials in the sampling chain that contact the gas potentially influence this stability.
This paper aims to review the available gas sampling and preconcentration techniques for determining trace compounds in biogas, landfill gas and biomethane. Techniques reviewed include 1) whole gas sampling methods (gas sampling bags, gas cylinders, canisters) and 2) gas sampling methods with preconcentration on solid media (sorbent tubes for physisorption or chemisorption, amalgamation, solid phase microextraction); preconcentration in liquid media (absorption in impingers); and cryogenic preconcentration. These techniques are reviewed for the sampling of nonmetal(loid) volatile organic trace compounds (aliphatic, aromatic, halogenated and oxygenated species; organic silicon compounds (siloxanes, silanes), and (in)organic sulfur compounds) as well as for volatile (in)organic metal(loid) compounds. The suitability of all presented sampling and preconcentration methods for given families of trace compounds regarding storage stability issues, is discussed as well as considerations regarding the ease of field implementation, advantages and disadvantages. This review highlights the intricate complexity of sampling trace compounds in biogas, landfill gas and biomethane. The different trace compounds indeed display extremely diverse physicochemical properties (volatility, polarity, reactivity …) which results in different stabilities in given sampling units so that no sampling method along can trap and recover all families of trace compounds.
The review finishes with a list of recommendations to select proper sampling units, materials and parameters and to apply suitable sample transport and storage conditions to safeguard the integrity of samples.
Accurate quantification of ultra-trace sulfur compounds in hydrogen by integrating fill-less trap pre-concentration with gas chromatograph and sulfur chemiluminescence detector
2022, International Journal of Hydrogen Energy
Citation Excerpt :
However, this modified inlet system can also affect the detection property of GC-SCD for SCs, which has not yet been fully understood and evaluated. For example, the packed solid adsorbents can suffer from the problems of adsorption capacity, desorption efficiency [33,34] and unique loss mechanism from different tubing types for each sulfur compound [35]. On the other hand, an accurate analysis of hydrogen impurity is extremely dependent on the hydrogen production, sampling and storage procedures.
Accurate quantification of ultra-trace impurities in hydrogen, e.g., <0.004 μmol·mol⁻¹ for total sulfur compounds as specified in ISO 14687-2019, is of paramount importance to ensure the quality of hydrogen for fuel cell vehicles. Here, we developed a novel fill-less trap pre-concentration inlet system integrated with GC-SCD for measuring ultra-trace sulfides in hydrogen. This analytical system can achieve an optimum method detection limit range of 0.002–0.004 nmol mol⁻¹ (ppb(v)) for sulfides by trapping 400 mL hydrogen sample. The modified fill-less trap inlet system can avoid the deviation of desorption efficiency from adsorbents and shows a wide linearity range of up to 150 ppb(v) in 400 mL that is one order of magnitude higher than existing packing pre-concentration. Response sensitivity biases from the calibration pattern of constant volumes exhibit better sensitivity with deviation of up to ∼10% smaller than constant concentrations at 0.1–10.0 ppb(v). The stability of sulfides in hydrogen at 0.1–4.0 ppb(v) stored in Silonite™ canisters are firstly investigated. Poor stability is observed for H₂S and EtSH of which each about 30% loss after 3 days storage, indicating that the hydrogen sample stored in Silonite™ containers should be analyzed within 4 days. Therefore, the developed analytical system with appropriate calibration pattern is well suitable for the accurate quantification of trace sulfides in hydrogen sampling from refueling station and production processing.
A preconcentration method based on a new sorbent for the measurement of selected reduced sulfur compounds at ppb level in ambient air
2018, Microchemical Journal
Odour annoyance forms the main source of environmental stress in residents living nearby industrial or agricultural fields. However, despite a relative simplicity of odour measurement at the emission source, odour measurement in the field is a quite more complicated task. Because of their low odour threshold and offensive odour, this study focuses on 6 reduced sulfur compounds (RSCs): methylmercaptan (MM), ethylmercaptan (EM), dimethylsulfide (DMS), isopropylmercaptan (IPM), tertbutylmercatpan (TBM), diethylsulfide (DES). Because of their very low concentrations in ambient air (few ppb), a preconcentration step is usually required. The literature points Tenax TA® as the more suitable sorbent for sulfur compounds adsorption but shows also an important impact of humidity and storage parameters inducing an underestimation of sulfur ambient air concentrations. So only qualitative or semi-quantitative data results are obtained with Tenax TA® samplings of targeted compounds. To guarantee quantitative concentration data, a new sampling device, using a S-Sorbent Tube₄₅₀ combined with an optimal drying device, was performed and optimized sampling and analysis parameters were determined. The assessment of uncertainties attests of quantitative measurements for 5 of the 6 RSCs (EM, DMS, IPM, TBM, DES) with relative expanded uncertainties less than 33% considering that samples were stored properly in freeze during 7 days. Only semi-quantitative measurements could be considered for MM with a global uncertainty estimated to 48%, storage contributing for a half.
Sampling of gaseous sulfur-containing compounds at low concentrations with a review of best-practice methods for biogas and natural gas applications
2015, TrAC - Trends in Analytical Chemistry
Citation Excerpt :
Other very high recoveries were obtained from silica gel and molecular sieve (90.4%) and silica gel alone (90.3%), with three sorbents (Carbotap 100, Carbotap 150 and Tenax TA) trapping negligible amounts of carbonyl sulfide. For the third compound studied, methanethiol [27] (at a mass of methanethiol equivalent to 6.57 ng of sulfur sampled from a gas mixture containing 26.9 µL L−1 of methanethiol), the best two performing tubes were silica gel and molecular sieve (99.2% recovery) and silica gel alone (96.4%), with negligible recoveries reported for Carbotrap 150, Carbotrap 400 and Carboxen 569. Andersen et al. [28] performed storage tests on inert coated stainless-steel sorbent tubes packed with Tenax TA (35/60) and carbonized molecular sieve (60/80) using a methanethiol volume fraction of 124 nL L−1 (diluted from a gas standard of 4.97 µL L−1 nitrogen).
The accurate quantification of low-concentration sulfur-containing compounds is essential for the biogas and natural gas industries. We review literature data for the stability of these compounds in standard gas mixtures when sampled in cylinders with different passivations, sample bags, sorbent tubes, solid-phase microextraction and glass sampling bulbs, and we present new data obtained at our three National Measurement Institutes. We show that losses of sulfur-containing compounds are minimized when using passivated sampling cylinders, and the most suitable sorbent material for sampling these compounds is Tenax TA. We also discuss methods for transferring gas from sample vessels to analyzers and give recommendations for the selection of regulators (and other pressure-reducing devices) and transfer lines. Further, we propose approaches that could be taken to reduce or correct for losses in order to provide more accurate measurements of sulfur-containing compounds.
The method for on-site determination of trace concentrations of methyl mercaptan and dimethyl sulfide in air using a mobile mass spectrometer with atmospheric pressure chemical ionization, combined with a fast enrichment/separation system
2014, Talanta
Citation Excerpt :
In the present study, Me2S and MeSH sorption capacity was found insufficient, which necessitated the use of silica gel instead of Tenax. Me2S and MeSH preconcentration was previously studied by Devai and colleagues [21], who obtained the best results using silica gel. Trapping and desorption property of silica gel for Me2S and MeSH analysis has received an additional approval during mass spectrometric investigation [9].
A method for fast simultaneous on-site determination of methyl mercaptan and dimethyl sulfide in air was developed. The target compounds were actively collected on silica gel, followed by direct flash thermal desorption, fast separation on a short chromatographic column and detection by means of mass spectrometer with atmospheric pressure chemical ionization. During the sampling of ambient air, water vapor was removed with a Nafion selective membrane. A compact mass spectrometer prototype, which was designed earlier at Trofimuk Institute of Petroleum Geology and Geophysics, was used. The minimization of gas load of the atmospheric pressure ion source allowed reducing the power requirements and size of the vacuum system and increasing its ruggedness. The measurement cycle is about 3 min. Detection limits in a 0.6 L sample are 1 ppb for methyl mercaptan and 0.2 ppb for dimethyl sulfide.
Minimisation of artefact formation of dimethyl disulphide during sampling and analysis of methanethiol in air using solid sorbent materials
2012, Journal of Chromatography A
Citation Excerpt :
Tangerman [10] reported that molecular sieve 5A has a large capacity for methanethiol at room temperature, but thermal desorption might be difficult due to strong retention of sulphur compounds. Devai and DeLaune [18] evaluated silanized glass tubes packed with various adsorbents and presented silica gel as the best adsorbent for sampling trace levels of MT. However, formation of DMDS is not mentioned. Furthermore, silica gel is highly hydrophilic and may thus adversely affect GC/MS performance.
Methanethiol (MT) is a potent odorant that can be difficult to measure due to its high volatility and reactivity; it easily reacts to form dimethyl disulphide (DMDS) during sampling and/or analysis. This paper focuses on finding an optimal method for sampling and measuring MT with minimum artefact formation using sorbent materials and a thermal desorption-gas chromatography–mass spectrometry method (TD-GC–MS). Experiments were conducted to identify suitable sorbent materials and tubes for analysis. Breakthrough, desorption rate, the effects of storage and desorption temperatures were investigated and different drying methods were established with respect to quantitative sampling and formation of DMDS. Proton-transfer-reaction mass spectrometry (PTR-MS) was used in the development of the method and was an especially useful tool for determination of breakthrough. The results show that glass tubes packed with silica gel for pre-concentration of MT before analysis with TD-GC–MS give the best results. In addition, a combination of Tenax TA and carbonised molecular sieve or Tenax TA cooled to ≤0 °C gives acceptable results. 80 °C was found to be the optimal desorption temperature. For all the sampling methods tested, storage conditions were observed to be very critical for transformation of MT. Room temperature storage should be limited to few minutes and, in general, tubes should be kept at 0 °C or lower during storage.

View all citing articles on Scopus

View full text

NoteEvaluation of various solid adsorbents for sampling trace levels of methanethiol

Abstract

Atmos. Environ.

Atmos. Environ.

Chemosphere

J. Ferment. Bioeng.

Atmos. Environ.

Atmos. Environ.

J. Ferment. Bioeng.

Atmos. Environ.

Biogenic sulfur source strengths

Env. Sci. Technol.

Odor control in liquid hog manure by added amandments and aeration

J. Environ. Qual.

Solid adsorbent preconcentration and gas chromatographic analysis of sulfur gases

Anal. Chem.

Volatile sulfur-compounds formed in disrupted tissues of different cabbage cultivars

J. Food Sci.

Trapping efficiency of various solid adsorbents for sampling and quantitative gas chromatographic analysis of carbonyl sulfide

Analytical Letters

Effect of different drying tubes on the reduced sulfur gas content of the sweep air

Acta Biol. Debr. Oecol. Hung.

Note
Evaluation of various solid adsorbents for sampling trace levels of methanethiol