Interactive effects of temperature, salt concentration, and pH on head space analysis for isolating volatile trace organics in aqueous environmental samples

Friant, S.L.; Suffet, I. H.

doi:10.1021/ac50049a027

Cited by 63 publications

(20 citation statements)

References 18 publications

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“…In fact, to this end, many studies have used a certified soil material with known concentrations of PAHs together with a reference biochar sample. For headspace methods, commonly employed for the identification of VOCs, vial temperature and equilibration time are the most crucial parameters for method development (Friant & Suffet, 1979;Penton, 1992). A natural soil containing 15 PAHs with concentrations ranging from 1.14 to 12.9 mg kg À1 was used together with an internal reference biochar sample (industrial-scale slow pyrolysis orchard prunings biochar).…”

Section: Methods Validation Using Soil and Biochar Samplesmentioning

confidence: 99%

Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar‐amended soil: a review

et al. 2016

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Residual pollutants including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and carbon (aceous) nanoparticles are inevitably generated during the pyrolysis of waste biomass and remain on the solid coproduct called biochar. Such pollutants could have adverse effects on the plant growth as well as microbial community in soil. Although biochar has been proposed as a ‘carbon negative strategy’ to mitigate the greenhouse gas emissions, the impacts of its application with respect to long‐term persistence and bioavailability of hazardous components are not clear. Moreover, the co‐occurrence of low molecular weight VOCs with PAHs in biochar may exert further phytotoxic effects. This review describes the basic need to unravel key mechanisms driving the storage vs. emission of these organics and the dynamics between the sorbent (biochar) and soil microbes. Moreover, there is an urgent need for standardized methods for quantitative analysis of PAHs and VOCs in biochar under environmentally relevant conditions. This review is also extended to cover current research gaps including the influence of biochar application on the short‐ and long‐term fate of PAHs and VOCs and the proper control tactics for biochar quality and associated risk.

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Section: Methods Validation Using Soil and Biochar Samplesmentioning

confidence: 99%

Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar‐amended soil: a review

et al. 2016

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“…To date, many studies have been conducted to evaluate the effect of such substances on the analysis of the volatile fraction of liquids such as apple juice [21], milk [22] or model aqueous solutions [23][24][25][26][27]. These investigations have shown that adding hygroscopic salts increases the vapor pressure and therefore the concentration of the volatile substances in the headspace of samples.…”

Section: Introductionmentioning

confidence: 99%

Effect of adding hygroscopic salts on the analysis of the volatile fraction of cheese

et al. 2000

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The dynamic headspace technique coupled with gas chromatography and mass spectrometry is frequently used to characterize the volatile fraction of food products [1][2][3][4][5][6][7]. However, water is very often the main volatile component and generates artefacts during the different steps of the analysis [8][9][10]. Several approaches to limit these artefacts have already been tested. They include acting on the sample or the adsorbent [11][12][13][14], inserting a water trap between the sample and the adsorbent [15][16][17][18], modifying injection parameters [19] or selecting a particular type of chromatographic column [20].Water activity in the sample can be lowered simply by mixing in hygroscopic substances such as salts or sugars. To date, many studies have been conducted to evaluate the effect of such substances on the analysis of the volatile fraction of liquids such as apple juice [21], milk [22] or model aqueous solutions [23][24][25][26][27]. These investigations have shown that adding hygroscopic salts increases the vapor pressure and therefore the concentration of the volatile substances in the headspace of samples. However, very little work has been published on the effects of using such salts in solid or semi-solid media [28].The objective of this work was therefore to determine whether or not the incorporation of various hygroscopic salts into cheese, which modifies both the structure and the physical and chemical properties of the product, could facilitate the analysis of its volatile fraction, and if so to what extent. Materials and methods SamplesCommercial wax-coated pre-portioned hard processed cheeses were selected (mini-Babybel ® ). Such samples are biochemically stable, homogeneous, and have a relatively simple volatile fraction. Their water content was 48 % and the relative humidity of their headspace was 72 %. Storage of samplesThe cheese samples in their original wax packaging were wrapped in aluminium foil, vacuum-sealed in polyethylene bags and stored at -25°C. Before each analysis the sample was left overnight at room temperature. Choice of saltsFive salts were chosen for their hygroscopic properties and their low reactivity toward the matrix of the products stud- n°28 114.365). The salts were dehydrated in an oven at 105°C before use. To determine the least quantity of salts necessary to obtain a dense homogeneous mixture with medium particle size, preliminary tests were conducted on the texture of the cheese-salt mixtures. For 4 g of cheese the quantities of salt to be added were: 4 g of calcium chloride, 2 g of magnesium sulfate, 6 g of potassium carbonate, 10 g Abstract. We investigated the effect of adding hygroscopic salts on the analysis by dynamic headspace -gas chromatographymass spectrometry of the volatile fraction of cheese. We tested five salts: calcium chloride, magnesium sulfate, potassium carbonate, sodium chloride and sodium sulfate. Relative humidity of the headspace, pH value of the matrix, desorption of volatile components and their odor were modified differentl...

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“…Its application can be expanded to the extraction of moderately polar substances by the addition of salt (such as Na2SO4) to a solute-poor solution (Friant & Suffet, 1979). Such treatments can shift the vapour-phase partitioning into the desired direction.…”

Section: Resultsmentioning

confidence: 99%

Pheromones in marine algae: A technical approach

Gassmann

Müller

Fritz

1995

Helgolander Meeresunters

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It is now well known that many marine organisms use low-molecular volatile substances as signals, in order to coordinate activities between different individuals. The study of such pheromones requires the isolation and enrichment of the secretions from undisturbed living cells or organisms over extended periods of time. The Grob-Hersch extraction device, which we describe here, avoids adverse factors for the biological materials such as strong water currents, rising gas bubbles or chemical solvents. Furthermore, the formation of sea-water spray is greatly reduced. The application of this technique for the isolation of pheromones of marine algae and animals is described.

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Interactive effects of temperature, salt concentration, and pH on head space analysis for isolating volatile trace organics in aqueous environmental samples

Cited by 63 publications

References 18 publications

Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar‐amended soil: a review

Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar‐amended soil: a review

Effect of adding hygroscopic salts on the analysis of the volatile fraction of cheese

Pheromones in marine algae: A technical approach

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