Work Description

Title: Supplemental file: Measurement of Short-chain Fatty Acids in Respiratory Samples: Keep Your Assay Above the Water Line Open Access Deposited
Attribute Value
  • For the measurement of SCFAs by gas chromatography (GC)-mass spectroscopy (MS) without derivatization using a previously published protocol (Anaerobe 2018; 53: 64-73). Methyl tert-butyl ether (MTBE) was used for liquid-liquid extraction of SCFAs from acidified EBC. Negative controls including MTBE alone, MTBE used to extract acidified water and internal standards, a water wash of the EBC acquisition equipment, and a representative sample of normal saline acquired from the bronchoscopy suite were also assayed. For our newly developed LC-MS assay, we applied the methods of Han, et al (Anal Chim Acta 2015; 854: 86-94). Briefly, samples were analyzed using an Agilent 6410 triple quadrupole LC-MS system. The chromatographic column was a Waters HSS T3, 2.1 mm x 100 mm, 1.7 µm particle size. Mobile phase A was 0.1% formic acid in water; mobile phase B was 0.1% formic acid in methanol. The gradient was as follows: linear ramp from 15% to 80% B from 0-12 min; step to 100%B from 12-12.1 min; hold 100%B from 12.1-16 min; step to 15%B from 16-16.1 min; hold 15%B from 16.1-20min. The injection volume was 5uL and the column temperature was 55 °C. MS parameters were as follows: gas temp 325 °C, gas flow 10 L/min, nebulizer 40 psi, capillary voltage 4000V, scan type MRM, negative ion mode, delta EMV 600. A post-mortem porcine portal vein plasma sample was assayed as a positive control for both assays.
  • This was a small descriptive study to determine whether short chain fatty acids (SCFAs) are detectable in water. It is part of a larger study that assessed the utility of exhaled breath condensate (EBC) as a biofluid for microbiome assays.
Contact information
Funding agency
  • National Institutes of Health (NIH)
Resource type
Last modified
  • 03/09/2020
  • 03/09/2020
To Cite this Work:
Yue, M., Kim, J., Evans, C., Kachman, M., Erb-Downward, J., D’Souza, J., Foxman, B., Adar, S., Curtis, J., Stringer, K. (2020). Supplemental file: Measurement of Short-chain Fatty Acids in Respiratory Samples: Keep Your Assay Above the Water Line [Data set]. University of Michigan - Deep Blue.


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