Monitoring hydrogen sulfide in simulated breath of anesthetized subjects

• Published in: International journal of mass spectrometry Vol. 354-355; pp. 139 - 143
• Main Authors: Koyanagi, Gregory K., Kapishon, Vitaliy, Blagojevic, Voislav, Bohme, Diethard K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2013
• Subjects: APCI-MS; Hydrogen sulfide; Quantification; Simulated breath; Sulfur oxide anion; Hydrogen sulfide; Simulated breath; Sulfur oxide anion; APCI-MS; Quantification
• ISSN: 1387-3806; 1873-2798
• DOI: 10.1016/j.ijms.2013.05.024

•We applied negative ion APCI mass spectrometry to the quantification of simulated breath containing air, water vapor, N2O and CO2.•We added CHCl3 to mimic the influence of halocarbons associated with the breath of anesthetized subjects.•Both SO2− and SO3− were observed to be sensitive to H2S down to about 1ppt (trillion). The observed ratio of [SO2−] to [SO3−] was found to be the most useful monitor of H2S.•SH− was found to be suppressed by CO2 and so unsuitable for H2S quantification in breath. Human breath can be a complex mixture of trace gases in humid air, with the addition of various anesthetizing agents it becomes even more complex and can present a challenge for the accurate quantification of components. The purpose of this paper was to investigate the quantification of H2S as a function of several potential matrix/interference compounds using negative-ion atmospheric pressure chemical ionization with mass spectrometric detection. Analysis was performed by humidifying zero-air and adding various compounds that would be encountered in a perioperative situation. Nitrous oxide, carbon dioxide and to a lesser extent humidity have significant effects on the instrument response to hydrogen sulfide concentration, while halogenated species were found to have little if any complicating effect. It was found that H2S can be accurately quantified by using either [SO3]− or [SO2]−/[SO3]−, both of which eliminate the response variability due to interferences.