Ammonia in breath and emitted from skin

Schmidt, Florian M.; Vaittinen, Olavi; Metsälä, Markus; Lehto, Markku; Forsblom, Carol; Groop, P-H; Halonen, Lauri

doi:10.1088/1752-7155/7/1/017109

Cited by 119 publications

(120 citation statements)

References 64 publications

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“…Others have used sampling methods which exclude the oral breath fraction and capture only the late tidal volume to avoid this issue (Gouma, 2012). The contribution made by oral bacteria in the measurement of ammonia levels in breath sampling remains an issue of some debate in breath research (Schmidt et al, 2013).…”

Section: The Digestive Systemmentioning

confidence: 99%

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

Brannelly

Shield

Killard

2016

Critical Reviews in Analytical Chemistry

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Section: The Digestive Systemmentioning

confidence: 99%

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

Brannelly

Shield

Killard

2016

Critical Reviews in Analytical Chemistry

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“…These may have important advantages and validity. A complete comparison is beyond the scope of the present work 10,11,12 .…”

Section: Introductionmentioning

confidence: 99%

Fast and Accurate Exhaled Breath Ammonia Measurement

Solga

Mudalel

Spacek

et al. 2014

JoVE

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This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels.Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive.The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations. Video LinkThe video component of this article can be found at

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“…On-line approaches with ambient-ionisation mass spectrometry have obtained in-vivo mass spectral "fingerprints" with desorption electrospray ionisation (DESI) [13], secondary electrospray ionisation (SESI) [14,15] and extractive electrospray ionisation (EESI) [16]. Sealing a participant's limb into a ventilated Tedlar bag and analysing the exhaust by selected ion flow tube mass spectrometry (SIFT-MS) provided targeted on-line acetone [17] and ammonia levels [18]. A proton transfer reaction mass spectrometry (PTR-MS) technique demonstrated how to sample synthetic-air directed over the skin's surface [19].…”

Section: Sampling Voc-profiles In Skinmentioning

confidence: 99%

Volatile organic compound markers of psychological stress in skin: a pilot study

Martin¹,

Turner²,

Bandelow³

et al. 2016

J. Breath Res.

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The forehead was studied as a possible sampling site for capturing changes in volatile organic compound (VOC) profiles associated with psychological-stress. Skin-VOCs were sampled with a polydimethylsilicone (PDMS)-coupon and the resulting VOCs were recovered and analysed with two-stage thermal desorption gas chromatography-mass spectrometry.15 young adult volunteers (19 yr to 26 yr) participated in two interventions run in a randomised crossover design. One intervention, termed "Neutral", required the participants to listen to peaceful music, the other, termed a "paced audio serial addition task", required the participants to undertake a series of rapid mental arithmetic calculations in a challenging environment that induced a stress response. Skin-VOC samples were taken during each intervention. The resultant data were processed with dynamic background compensation, deconvolved, and registered to a common retention index scale.The importance of freezing skin patch samplers to -80 o C was determined during the method development phase of this study. The cumulative distribution function of the GC-MS data indicates the possibility that PDMS-coupons are selective towards the lower volatility VOC components in skin. The frequency distribution of the GC-MS data was observed to be approximately log-normal, and on the basis of this study, a further twoorders of magnitude reduction in sensitivity may be required before the complete skin-VOC profile may be characterised.Multi-variate analysis involving Pareto-scaling prior to partial least squares discriminant analysis identified four VOCs with the highest probability of contributing to the variance between the two states, and the responses to these VOCs were modelled with principle components analysis (PCA). Two VOCs, benzoic acid and n-decanoic acid were upregulated (14-and 8-fold respectively) and appear to be PASAT sensitive, with areas under (AUC) their receiver operator characteristic (ROC) curves of 0.813 and 0.852 respectively. A xylene isomer and 3-carene were down regulated 75 % and 97% respectively, and found to be predictive of the neutral intervention (ROC AUC values of 0.898 and 0.929 respectively). VOC profiles in skin appear to change with stress either due to increased elimination, elevated bacterial activity, or perhaps increased oxidative pathways.2

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Ammonia in breath and emitted from skin

Cited by 119 publications

References 64 publications

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

Fast and Accurate Exhaled Breath Ammonia Measurement

Volatile organic compound markers of psychological stress in skin: a pilot study

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