Abstract

Volatile organic compounds (VOCs) released through skin (transcutaneous gas) has been increasing in importance for the continuous and real-time assessment of diseases or metabolisms. For stable monitoring of transcutaneous gas, finding a body part with little interference on the measurement is essential. In this study, we have investigated the possibility of external ears for stable and real-time measurement of ethanol vapour by developing a monitoring system that consisted with an over-ear gas collection cell and a biochemical gas sensor (bio-sniffer). The high sensitivity with the broad dynamic range (26 ppb–554 ppm), the high selectivity to ethanol, and the capability of the continuous measurement of the monitoring system uncovered three important characteristics of external ear-derived ethanol with alcohol intake for the first time: there is little interference from sweat glands to a sensor signal at the external ear; similar temporal change in ethanol concentration to that of breath with delayed peak time (avg. 13 min); relatively high concentration of ethanol relative to other parts of a body (external ear-derived ethanol:breath ethanol = 1:590). These features indicated the suitability of external ears for non-invasive monitoring of blood VOCs.

Highlights

  • Volatile organic compounds (VOCs) released through skin has been increasing in importance for the continuous and real-time assessment of diseases or metabolisms

  • When the ethanol vapor reaches the Alcohol dehydrogenase (ADH) membrane, the catalysed redox reaction occurs at the membrane together with N­ AD+ in the buffer solution running above the membrane, which produces NADH in the buffer solution

  • We have examined the possibility of the external ear for stable monitoring of transcutaneous VOC by developing the monitoring system

Read more

Summary

Introduction

Volatile organic compounds (VOCs) released through skin (transcutaneous gas) has been increasing in importance for the continuous and real-time assessment of diseases or metabolisms. 13 min); relatively high concentration of ethanol relative to other parts of a body (external ear-derived ethanol:breath ethanol = 1:590) These features indicated the suitability of external ears for non-invasive monitoring of blood VOCs. Exhaled breath and transcutaneous gas contain volatile organic compounds (VOCs) from b­ lood[1]. There are highly sensitive analytical methods for VOCs in exhaled breath and transcutaneous gas, such as gas chromatography mass spectrometry (GC–MS)[7], proton-transfer-reaction mass spectrometry (PTR-MS)[8] that is often coupled with time of flight mass analyser (PTR–TOF–MS)[9], and selected-ion flow-tube mass spectrometry (SIFT-MS)[10] Their capability of identifying VOC composition is powerful for comprehensive analysis of the gas, the size and complexity of the system are drawbacks for monitoring transcutaneous VOC. Yamada et al presented a semiconductor-based portable sensor for transcutaneous blood acetone, which utilized zeolite to concentrate acetone before ­measurement[13,14]

Methods
Results
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.