Journal of Chromatography A vol:896 issue:1-2 pages:135-148
In this paper an identification method is described for determining the degradation products of the reaction of or-pinene with hydroxyl radicals. The study is carried out in a fast-flow reactor equipped with a specially designed microwave cavity (type Surfatron) allowing to operate at pressures up to 100 Ton (1 Torr = 133.322 Pa). The semivolatile products are collected on a liquid nitrogen trap (LN2 trap) and the batch samples are subsequently analysed by GC-MS and HPLC-MS. Some samples were also collected directly on a LpDNPH-cartridge, followed by HPLC-MS analysis. When experiments were carried out at 50 Ton both GC-MS and HPLC-MS measurements showed that campholenealdehyde and pinonaldehyde were identified as condensable oxidation products for the alpha -pinene/OH reaction, with pinonaldehyde being the main product. Furthermore, the LN2 trap collection method based on the in situ conversion of aldehydes and ketones to their 2,4-dinitrophenylhydrazone derivatives allowed the determination of formaldehyde, acetaldehyde and acetone. Although formaldehyde and acetone are present in small amounts in blank samples, it could be established that formaldehyde and acetone are also formed in the alpha -pinene/OH reaction. (C) 2000 Elsevier Science B.V. All rights reserved.