Accurate and sensitive analysis of sulfur aroma compounds in tobacco by NADES-enhancing HS-SPME Arrow coupled with GC-Orbitrap-MS

The identification and measurement of sulfur aroma compounds (SACs) to precisely describe tobacco quality and style have remained as significant topics in tobacco research for many years. However, the ultra-trace quantification of SACs in complex tobacco matrices poses a considerable challenge in analytical area. In this study, an accurate and sensitive analysis of SACs in tobacco through a natural deep eutectic solvent (NADES) enhancing headspace-solid-phase microextraction (HS-SPME) Arrow combined with GC-Orbitrap was developed. The NADES system composed of choline chloride and D-glucose (CCGlu) in the pretreatment possessed excellent enhancement of HS-SPME Arrow extraction efficiency for natural tobacco targets. To improve selectivity, GC-Orbitrap was applied that prominently reduced chemical interferences from the tobacco matrix, improving confidence in the determination and identification of SACs in tobacco. During method validation, the limit of quantification (LOQ) ranged from 0.07 to 5.97 ng/g, apparently lower than those reported previously. And acceptable accuracies were attained with relative recoveries ranging from 85.4 % to 111 %. Finally, the developed method was applied to 45 Virginia tobacco samples, and 23 SACs were identified, among which 11 analytes were detected for the first time in this study. The results were preliminarily analyzed using principal component analysis, demonstrating that SACs could be employed as useful variables to characterize the aroma types and geographical origins of tobacco in China, which might be suitable for monitoring tobacco quality.