scholarly journals The Impact of a Graded Maximal Exercise Protocol on Exhaled Volatile Organic Compounds: A Pilot Study

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 370
Author(s):  
Liam M. Heaney ◽  
Shuo Kang ◽  
Matthew A. Turner ◽  
Martin R. Lindley ◽  
C. L. Paul Thomas

Exhaled volatile organic compounds (VOCs) are of interest due to their minimally invasive sampling procedure. Previous studies have investigated the impact of exercise, with evidence suggesting that breath VOCs reflect exercise-induced metabolic activity. However, these studies have yet to investigate the impact of maximal exercise to exhaustion on breath VOCs, which was the main aim of this study. Two-litre breath samples were collected onto thermal desorption tubes using a portable breath collection unit. Samples were collected pre-exercise, and at 10 and 60 min following a maximal exercise test (VO2MAX). Breath VOCs were analysed by thermal desorption-gas chromatography-mass spectrometry using a non-targeted approach. Data showed a tendency for reduced isoprene in samples at 10 min post-exercise, with a return to baseline by 60 min. However, inter-individual variation meant differences between baseline and 10 min could not be confirmed, although the 10 and 60 min timepoints were different (p = 0.041). In addition, baseline samples showed a tendency for both acetone and isoprene to be reduced in those with higher absolute VO2MAX scores (mL(O2)/min), although with restricted statistical power. Baseline samples could not differentiate between relative VO2MAX scores (mL(O2)/kg/min). In conclusion, these data support that isoprene levels are dynamic in response to exercise.

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 795-800
Author(s):  
Allen Apblett ◽  
Nicholas Materer ◽  
Evgueni Kadossov ◽  
Shoaib Shaikh

ABSTRACT Introduction Military personnel are exposed to a broad range of potentially toxic compounds that can affect their health. These hazards are unpredictable because military service occurs in a wide array of uncontrolled environments. Therefore, a novel sorbent was developed that allows the fabrication of lightweight personal samplers that are both capable of sorbing an extremely wide range of organic chemical types and able to stabilize reactive compounds. Materials and Methods OSU-6, a nanoporous silica, was provided by XploSafe LLC. The sorption capacity for several volatile organic compounds, the temperatures required for thermal desorption of adsorbed compounds, and the sampling rates for targeted analytes were determined. Results The uptake capacity was found to be on average 1.5 g/g of sorbent. Analytes were not only held tightly but also could be desorbed upon heating the sorbate to temperatures below 150°C. Sampling rates for volatile organic compound by an OSU-6 sampler badge were on average, 5.7 times higher than those for a commercially available activated carbon badge. Theoretical calculations showed that sorption of volatile organic compounds on the surface of the tightly curved pore walls in OSU-6 is because of exceptionally strong cumulative addition of Van der Waals forces. Analytes could readily be analyzed by either solvent extraction or thermal desorption gas chromatography/mass spectrometry techniques. Excellent sampling rates, high concentrations of analytes in the OSU-6 sorbent matrix, and high desorption efficiencies (recoveries) were obtained using the thermal desorption method. Conclusions The performance of the OSU-6 sorbent makes it highly capable of meeting the need for personal samplers that enable Individual Longitudinal Exposure Records development. It can adsorb an extremely wide array of different volatile organic compounds, it can stabilize reactive compounds, it has high sampling rates coupled with high capacity that provide both sensitivity and resistance to saturation, and it is unique in being very amenable to thermal desorption in combination with having strong sorbate binding and high capacity and surface area.


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