Concentrating breath samples using liquid nitrogen: a reliable method for the simultaneous determination of ethane...

Area of Science:

• Biochemistry
• Analytical Chemistry
• Animal Physiology

Background:

• Breath analysis of ethane and pentane is a noninvasive method for assessing in vivo lipid peroxidation.
• Technical challenges in sample collection and concentration have limited the application of these breath biomarkers.

Purpose of the Study:

• To develop a simple, rapid, and reliable method for collecting, concentrating, and measuring breath ethane and total-body pentane in rats.
• To improve upon existing cryofocusing techniques for volatile alkane detection in breath samples.

Main Methods:

• Developed a novel method to concentrate alkanes from rat breath using adsorbent material cooled to -174°C.
• Collected and analyzed breath samples from rats, comparing the new method to a -130°C cryofocusing technique.

Main Results:

• The -174°C method effectively trapped volatile ethane, outperforming the -130°C technique.
• Ethane was predominantly measured in breath, while pentane originated from both breath and other sources.
• Mean ethane evolution rate was 1.08 pmol/100 g body wt/min; pentane evolution rate was 0.52 pmol/100 g body wt/min with higher variability.
• Rat feces were identified as a significant source of both ethane and pentane.

Conclusions:

• The developed method offers a superior approach for measuring breath ethane and pentane in rats.
• This technique enhances the potential for noninvasive assessment of lipid peroxidation using breath biomarkers.
• Further research is needed to elucidate the sources of pentane and the implications of fecal ethane and pentane excretion.