Determination and characterization of the pyrolysis products of isoprocarb by GC-MS

The pyrolysis behavior of isoprocarb (an insecticide with contact and stomach action) is investigated using pyrolysis-gas chromatography-mass spectrometry. The pyrolysis products are separated using an HP-5 column under temperature program with helium as the carrier gas. The total of 80 separated pyrolysis components at 600°C, 750°C, and 900°C under helium atmosphere are identified using a probability-based matching search procedure, combined with the correlation of boiling point (BP) and Lee retention index (RI). Some of the BP values of the tentative components are estimated using the group contributions method because experimental values are not available. The levels of the identified components are estimated by the peak area normalization method from the chromatogram. It is found that isoprocarb decomposes more with the increase of temperature, and a large number of mono aromatics and polycyclic aromatic hydrocarbons and their derivatives are produced when the pyrolysis temperature is higher than 750°C. The content of the decomposition products in the pyrolysate varies from 0.04% to 22.20%.