Background: Aldehydes and ketones are quite interesting volatile organic components of exhaled breath resulting from oxidative stress. The low breath concentration levels (tens to hundreds pptv) and high chemical reactivity make their analyses challenging. In this work, a method for the determination of carbonyl compounds in exhaled breath based on on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry (TD-GC-MS/MS) is presented. Methods: Analytical performances were optimized for a mixture of C2-C9 aldehydes and C3-C9 ketones by using an internal standard and a 23 full factorial design. A volume of sample (250 mL) was loaded at 50 mL/min into a sorbent tube packed with 250 mg of Tenax GR containing 130 nmol of O- (2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride. An aliquot (25 μL) of a 6D-acetone gaseous mixture (870 ppmv) was injected while loading the sample. After 24h at 37°C, sorbent tubes were analyzed by TD-GC-MS/MS. This procedure allowed the determination of carbonyl compounds in twelve breath samples collected from four heart failure patients during hospitalization. Results: All compounds showed a limit of detection lower than 200 pptv, except acetaldehyde (1 ppbv). The use of 6D-acetone as internal standard to normalize the yield of the derivatization reaction halved the relative standard deviation to 10 and 15% for mono- and di-carbonyl compounds, respectively. Breath acetone, 2-pentanone, 3-hydroxy-2-butanone, 2,3-butandione, and hexanal decreased in all patients along with the improved clinical conditions. Conclusions: A reliable and sensitive method for the determination of carbonyl compounds in exhaled breath by on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry was developed. Results highlighted its potential utility in clinical applications where oxidative stress alters the normal breath pattern of carbonyl compounds.
Determination of carbonyl compounds in exhaled breath by on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry
Tommaso Lomonaco
;Andrea Romani;Silvia Ghimenti;Denise Biagini;Massimo Onor;Pietro Salvo;Roger Fuoco;Fabio Di Francesco
2018-01-01
Abstract
Background: Aldehydes and ketones are quite interesting volatile organic components of exhaled breath resulting from oxidative stress. The low breath concentration levels (tens to hundreds pptv) and high chemical reactivity make their analyses challenging. In this work, a method for the determination of carbonyl compounds in exhaled breath based on on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry (TD-GC-MS/MS) is presented. Methods: Analytical performances were optimized for a mixture of C2-C9 aldehydes and C3-C9 ketones by using an internal standard and a 23 full factorial design. A volume of sample (250 mL) was loaded at 50 mL/min into a sorbent tube packed with 250 mg of Tenax GR containing 130 nmol of O- (2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride. An aliquot (25 μL) of a 6D-acetone gaseous mixture (870 ppmv) was injected while loading the sample. After 24h at 37°C, sorbent tubes were analyzed by TD-GC-MS/MS. This procedure allowed the determination of carbonyl compounds in twelve breath samples collected from four heart failure patients during hospitalization. Results: All compounds showed a limit of detection lower than 200 pptv, except acetaldehyde (1 ppbv). The use of 6D-acetone as internal standard to normalize the yield of the derivatization reaction halved the relative standard deviation to 10 and 15% for mono- and di-carbonyl compounds, respectively. Breath acetone, 2-pentanone, 3-hydroxy-2-butanone, 2,3-butandione, and hexanal decreased in all patients along with the improved clinical conditions. Conclusions: A reliable and sensitive method for the determination of carbonyl compounds in exhaled breath by on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry was developed. Results highlighted its potential utility in clinical applications where oxidative stress alters the normal breath pattern of carbonyl compounds.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
