Journal of Chromatography A vol:915 issue:1-2 pages:75-83
In this paper a method is described for determining and quantifying the degradation products of the reaction of cr-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 semi-volatile products are collected on a Liquid nitrogen trap (LN, trap) coated with a 2,4-dinitrophenylhydrazine (2,4-DNPH) solution and the batch samples are subsequently analyzed by HPLC. In order to perform quantitative measurements the batch samples contained two internal standards: benzaldehyde-2,4-DNPH and tolualdehyde-2,4-DNPH, In the experiments carried out at 50 Torr and 100 Ton, HPLC measurements showed that the semi-volatile products formaldehyde, acetaldehyde, acetone, campholenealdehyde and pinonaldehyde could be quantified as oxidation products for the alpha -pinene/OH reaction, with pinonaldehyde being the main product. Assuming that all these five oxidation products have the same collection efficiency on the LN, trap, one arrives at the following relative product yields (expressed in mol %) at 50 and 100 Ton, respectively: 9.7 +/-0.7 and 6 +/-5 for formaldehyde; 1.1 +/-0.1 and 0.9 +/-0.5 for acetaldehyde; 16 +/-1 and 6 +/-2 for acetone; 11 +/-2 and 5.5 +/-0.7 for campholenealdehyde; 63 +/-3 and 82 +/-7 for pinonaldehyde. (C) 2001 Elsevier Science B.V. All rights reserved.