Abstrakt
Present study describes a combination of fast-GC with SIFT-MS analytical technique for selective analyses of biogenic volatile organic compounds (BVOCs) that play a critical role in atmospheric chemistry; they are associated with surface ozone production and secondary aerosol formation [1, 2]. Proper estimation of their concentration is necessary for the purpose of atmospheric photochemical modelling.
Currently, the accurate amount of non-methane biogenic emissions, represented mainly by methanol, isoprene and monoterpenes which belong to the most important plant volatiles (present at concentrations below 1 part per billion by volume, ppbv), is uncertain due to a lack of selective and robust in-situ analytical methods and instruments. SIFT-MS is able to quantify wide range of volatile organic compounds simultaneously in real time, anyway selectivity is still limited; only the total concentration of monoterpene isomers can be quantified.
Thus, more traditional method of gas chromatography (GC) has to be employed. Because GC is time consuming we have used fast-GC [3, 4] coupled to SIFT-MS [5].
For investigation, we used 5 m long metal MXT-1 column (0.28mm x 0.1 um) used previously [6] with resistivity ~4.2 W/m requiring heating current below 5 A. A separate investigation of elution times combined with ion chemistry [7] for eight the most abundant plant monoterpene isomers (α-pinene, β-pinene, Camphene, Myrcene, 3-carene, R-limonene, α-terpinene and γ-terpinene) were used for successful separation and identification of monoterpenes contained in an artificially prepared monoterpene mixture as well as in several biological samples.