Fast online two-dimensional analysis of monoterpenes using multi-capillary column high-pressure photoionization time-of-flight mass spectrometry

Abstract

One of the most abundant biological volatile organic compounds (BVOCs) in the atmosphere, monoterpene, is characterized by its short lifetime, low concentration, fast temporal and spatial variations, and wide variety of isomers. In this study, a multi-capillary column (MCC) was combined with high-pressure photoionization time-of-flight mass spectrometry (HPPI-TOF MS) and employed to develop an MCC-HPPI-TOF MS combination instrument as an online two-dimensional gas chromatography-mass spectrometry (GC-MS) method for the rapid qualitative and quantitative analysis of monoterpene isomers. As a result, six monoterpene isomers, α -pinene, β -pinene, α -terpinene, γ -terpinene, 3-carene, and limonene, were successfully isolated in 180 s with limits of detection (LODs) as low as 6 μg/m3 without sample pre-enrichment. This method was successfully applied to the rapid online analysis of monoterpenes released from the branches and leaves of Cedrus atlantica and Sabina chinensis, which shows the capability and potential application of the method for the online detection of complex sample mixtures in environmental monitoring, process analysis, and other fields.