Continuous Measurement of Dissolved Gases in Biochemical Systems with the Quadrupole Mass Spectrometer

Degn, Hans; Cox, Raymond P.; Lloyd, David

doi:10.1002/9780470110522.ch3

Cited by 59 publications

(4 citation statements)

References 73 publications

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“…Membrane inlet mass spectrometry has been used previously for on-line monitoring of volatile substrates, intermediates, and products during microbial processes (Degn et al, 1985;Lauritsen and Lloyd, 1994). For example, 2,3butanediol, acetoin, acetic acid, and ethanol were monitored in fermentations of Klebsiella oxytoca (Hayward et al, 1990), phenoxyacetic acid in fermentations of Penicillium chrysogenum (Hansen et al, 1994), and degradation of chloroethylenes by Methylococcus capsulatus (Lauritsen and Gylling, 1995).…”

Section: Introductionmentioning

confidence: 99%

On‐line monitoring of important organoleptic methyl‐branched aldehydes during batch fermentation of starter culture Staphylococcus xylosus reveal new insight into their production in a model fermentation

Petersen¹,

Beck²,

Lauritsen³

2003

Biotech & Bioengineering

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A small fermentor (55 mL) was directly interfaced to a membrane inlet mass spectrometer for continuous on-line monitoring of oxygen and volatile metabolites during batch fermentations of the starter culture Staphylococcus xylosus. Using this technique, we were able to correlate production of the very important flavor compounds 2-methylbutanal, 3-methylbutanal, and 2-methylpropanal with various growth conditions. We found that the aldehydes were present in the culture broth only as transient metabolites. They were produced in the exponential growth phase, reached a maximum concentration when the culture became anaerobic, and then they rapidly disappeared from the culture medium. This general pattern was observed for three different strains of S. xylosus and S. carnosus. Small amounts of inoculum or increased exposure to oxygen were found to favor production of the aldehydes as a result of a longer aerobic growth period. Growing S. xylosus under conditions resembling those in a fermented sausage revealed that NaCl (5%) increased aldehyde production considerably, whereas KNO(3) (0.03%) or NaNO(2) (0.03%) had little effect. A lowering of pH from 7.2 to 6.0 reduced cell density, but had a minor affect on aldehyde production.

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Section: Introductionmentioning

confidence: 99%

On‐line monitoring of important organoleptic methyl‐branched aldehydes during batch fermentation of starter culture Staphylococcus xylosus reveal new insight into their production in a model fermentation

Petersen¹,

Beck²,

Lauritsen³

2003

Biotech & Bioengineering

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“…MIMS analyses have been used for laboratory determination of the concentration of gases and volatile organic compounds (VOCs) in both gaseous and aqueous samples since the 1960s. 6,[14][15][16][17][18] For aqueous samples, which are the focus of this report, concentrations are typically determined by establishing steady-state diffusion conditions or using flow injection analysis (FIA). 17 The steady-state signal is then linearly related to the concentration of the particular analyte.…”

mentioning

confidence: 99%

“…The method was tested in two different laboratories using membrane inlet mass spectrometry (MIMS). MIMS analyses have been used for laboratory determination of the concentration of gases and volatile organic compounds (VOCs) in both gaseous and aqueous samples since the 1960s. ,− For aqueous samples, which are the focus of this report, concentrations are typically determined by establishing steady-state diffusion conditions or using flow injection analysis (FIA) . Under steady-state conditions, the sample is flushed through the membrane inlet until steady-state flow of analytes through the membrane has been established and the mass spectrometer signals have stabilized at a certain level.…”

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confidence: 99%

Method for Quantification of Chemicals in a Pollution Plume Using a Moving Membrane-Based Sensor Exemplified by Mass Spectrometry

et al. 2007

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Quantification of a chemical concentration in a pollution plume using a moving membrane-based sensor can be problematic. In many cases, the sensor passes through the plume faster than the time necessary to reach a steady-state signal, which is often used for quantification. Since the exposure time is typically not known, quantification based upon the flow injection analysis principle is also impractical. In this paper, we present a two-dimensional calibration model, exemplified by membrane inlet mass spectrometry, in which the concentration of a chemical can be determined using a simple algorithm. The concentration is given by a calibration factor, which is multiplied by the peak height and divided by the value of a polynomial, calculated at a normalized peak width. The model is demonstrated to give good quantitative estimates of concentrations for exposure times down to approximately 1/10 of the time it takes to reach steady-state diffusion through the membrane. Although the model is demonstrated using membrane inlet mass spectrometry and detection of volatile organic chemicals, it should be generally applicable to many membrane-covered sensors.

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“…Liquid‐phase microextraction using hollow fiber membranes (LPME‐HF) has recently been developed 17–22. It is an efficient sampling tool with many advantages such as simplicity, high sensitivity and low cost 18–22. However, the traditional LPME‐HF method is performed by combining a hollow fiber with a microsyringe needle.…”

mentioning

confidence: 99%

A liquid‐phase microextraction method, combining a dual gauge microsyringe with a hollow fiber membrane, for the determination of organochlorine pesticides in aqueous solution by gas chromatography/ion trap mass spectrometry

Yan

2004

Rapid Comm Mass Spectrometry

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A liquid-phase microextraction (LPME) method has been demonstrated for the extraction and determination of organochlorine pesticides (OCPs) in aqueous solution. The method combines a dual gauge microsyringe with a hollow fiber membrane (LPME/DGM-HF) followed by detection by gas chromatography/ion trap mass spectrometry (GC/ITMS). The advantages include speed, low solvent and sample consumption, simplicity and ease of use. The extraction time, solvent selection, salt concentration and sample stirring rate have been investigated in order to optimize extraction efficiency. The viability is evaluated by measuring the linearity and detection limit of the five OCPs in aqueous solution. Detection linearity for the OCPs has been achieved over a range of concentrations between 1 and 500 microg/L (r2 > 0.930), with a detection limit of 0.1 microg/L for each OCP.

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Continuous Measurement of Dissolved Gases in Biochemical Systems with the Quadrupole Mass Spectrometer

Cited by 59 publications

References 73 publications

On‐line monitoring of important organoleptic methyl‐branched aldehydes during batch fermentation of starter culture Staphylococcus xylosus reveal new insight into their production in a model fermentation

On‐line monitoring of important organoleptic methyl‐branched aldehydes during batch fermentation of starter culture Staphylococcus xylosus reveal new insight into their production in a model fermentation

Method for Quantification of Chemicals in a Pollution Plume Using a Moving Membrane-Based Sensor Exemplified by Mass Spectrometry

A liquid‐phase microextraction method, combining a dual gauge microsyringe with a hollow fiber membrane, for the determination of organochlorine pesticides in aqueous solution by gas chromatography/ion trap mass spectrometry

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