Human breath analysis

The general aim of this chapter is to contribute to the establishment of a fast and low-cost device for human breath analysis in addition to inveshgahons of blood and urine as a non-invasive standard method in hospitals and point-of-care centers for different medical apphcahons. On the basis of miniaturized ion mobihty spectrometry (IMS), the fuU procedure, including sampling, pre-separahon and idenhficahon of metabolites in human exhaled air, will be developed and implemented with re-... 

Thorpe, M. J., Balslev-Clausen, D., Kirchner, M. S. and Ye, J. (2008) Cavity-enhanced optical frequency comb spectroscopy application to human breath analysis . Optics Express, 16(4), 2387-2397. 

The potential of this SIFT/MS analytical method is enormous for human breath analysis and hence in physiology and biochemistry, for clinical diagnosis and therapeutic monitoring, and for measuring air... 

Lan and Mottola [14] have presented two continuous-flow-sensing strategies for the determination of C02 in gas mixtures using a special reaction cell. Both approaches are based on the effect of the complex of Co(II) with phthalocyanine as a rate modifier of the CL emission generated by luminol in the absence of an added oxidant agent, which is enhanced by the presence of C02 in the system. This enhancement allows the fast and simple determination of carbon dioxide at ppm levels (v/v) in atmospheric air and in human breath. In the first case, a continuous monitoring system was applied however, because the flow of expired gas is not constant, a discrete sample introduction approach was used in the analysis of C02 in breath. 

Thomas KW, Pellizzari ED, Cooper SD. 1991. Canister based method for collection and GC/MS analysis of volatile organic compounds in human breath. J Anal Toxicol 15 54-59. 

Benoit FM, Davidson WR, Lovett AM, Ngo A. Breath analysis by APl/MS—human exposure to volatile organic solvents. Int. Arch. Occup. Envir. Health 1985 55 113-20. 

Sensors for Breath Analysis An Advanced Approach to Express Diagnostics and Monitoring of Human Diseases... 

This study demonstrates high efficacy and expediency of the TCNQ derivative-based point-contact multistracture as a prospective asset for development of new sensors. The complex character of the sensors response curve and correlation of some response characteristics with different pathological manifestations in human breath, may be further used as a noninvasive diagnostic method alternative to some invasive approaches currently routinely used in clinic. The need for reliable and feasible gas analysis methods functional in presence of atmospheric air, opens opportunities for application of the proposed sensor technique in other spheres of human activity. High sensitivity of the point-contact multistructure enabling analysis of composite gas mixtures, opens up wide possibilities to apply the demonstrated approach for environment and health protection, such as detection of trace amounts... 

Sanchez, J.M., Sacks, R.D. (2006) Development of a multibed sorption trap, comprehensive two-dimensional gas chromatography, and time-of-flight mass spectrometry system for the analysis of volatile organic compounds in human breath. Anal. Chem. 78 3046-3054. 

Grote, C. and I. Pawliszyn (1997). Solid-phase microextraction for the analysis of human breath. Anal Chem., 69, 587-596. 

Fleischer, M. Simon, E. Rumpel, E. Ulmer, H. Harbeck, M. Wandel, M. Fietzek, C. Weimar, U. Meixner, H., Detection of volatile compounds correlated to human diseases trough breath analysis with chemical sensors, Sens. Actuators B 2002, 83, 245-249... 

Jansson, B.O., Larsson, B.T. Analysis of organic compounds in human breath by gas chromatography mass spectrometry. J. Lab. Clin. Med. 74, 961-966, 1969. 

Munson and Field reported in 1966 on a technique of ionizing molecules by gas phase ion-molecule reactions, which they called chemical ionization (Cl). In this way, break-up of the molecules can be greatly reduced or even avoided. Thus, measured ion currents can be correlated with the densities of the respective parent neutral compounds, allowing for on-line monitoring of rather complex gas mixtures. The fundamental principles of gas phase ion chemistry on which Cl is based, as well as the instrumentation for Cl, have been reviewed in great detail by Harrison." The wide variety of Cl methods that has been developed includes Medium Pressure Mass Spectrometry, Fourier Transform Mass Spectrometry, Quadrupole Ion Trap Mass Spectrometry, Pulsed Positive Ion-Negative Ion Chemical Ionization, and Atmospheric Pressure Ionization Mass Spectrometry (API-MS). Of these, API-MS has developed into a very reliable and widely used technique for analysis of VOCs in flavor release studies and human breath. A variety of API-MS applications in these fields of research has been described in a recent volume by Roberts and Taylor. ... 

It is quite stunning that up to now VOC analysis of the human breath has hardly been used for medical diagnostic purposes, but from the data... 

There are many applications for conductimetric measurements, some of which are very specific. For example, in a medical application, a conductivity sensor has been used to determine levels of ammonia in human breath In the same article, the authors also demonstrated a second sensor for breath analysis of carbon dioxide. In environmental analysis, a samarium iron oxide (SmFeOs) gas sensor has been developed for the detection of ozone based on conductance at sub-ppm levels ". ... 

Finally, the importance of human studies was emphasized -not only studies in human volunteers, or epidemiological research, but also the use of breath analysis, human lymphocytes, hemoglobin, etc. as indices of exposure and of effects of such exposure. The suggestion of a human liver bank was also discussed. 

Both of these approaches allow for assessment of systemic absorption by not conducting complete mass balance studies (e.g., expired air to catch absorbed compound metabolized to COj or HjO expired end products). In vivo dermal absorption studies not taking into account other routes of excretion must be interpreted with caution. One extension of this mass balance excretory analysis is to assess dermal absorption by only monitoring the primary excretory route for the compound studied. Dermal bioavailability has been assessed in exhaled breath using real-time ion trap mass spectrometry to track the uptake and ehmination of compounds (e.g., trichloroethylene) from dermal exposure in humans and rats (Poet et al., 2000). A physiologically based pharmacokinetic model can be used to estimate the total bioavailability of compoimds. The same approach was extended to determine the dermal uptake of volatile chemicals imder non-steady-state conditions using real-time breath analysis in rats, monkeys, and humans (Thrall et al., 2000). 

Poet, T.S., Corley, R.A., Thrall, K.D., Edwards, J.A., Tranojo, H Weitz, K.K., Hui, X., Maibach, H.I., and Wester, R.C., 2000, Assessment of the percutaneous absorption of trichloroethylene in rats and humans using MS/MS real-time breath analysis and physiologically based pharmacokinetic modeling, Toxicol. Set, 56, 61-72. 

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