Analytical Fast Pyrolysis of Nitrogen-Rich Mosquito Species via Pyrolysis-FTIR and Pyrolysis-GC/MS

This study presents a thorough thermal analysis of the dead remains of mosquitoes, in order to unravel the composition of vapors evolved from the bug zappers decimating them. Analytical pyrolysis-gas chromatograph/mass spectrometry (Py-GC/MS) and pyrolysis-Fourier transform infrared (Py-FTIR) spectrometric techniques were used to understand the pyrolysate composition and their time evolution from mosquitoes. Thermogravimetric mass loss data obtained at different heating rates (5–30 °C min-1) were used to determine the variation of apparent activation energy with conversion using isoconversional methods of Friedman, Flynn-Wall-Ozawa and Kissinger–Akahira–Sunose. The apparent activation energies varied in the range of 90-200 kJ mol-1. Increase in pyrolysis temperature from 400 to 700 °C resulted in the formation of alcohols, indoles, nitriles, monoaromatics and alkenes in higher selectivities, while the selectivity to long chain carboxylic acids decreased with increasing temperature. The formation of various organics was corroborated by the evolution of functional groups at short timescales. The significant nitrogen content in the char (∼9.7 wt.%) was evidenced in the form of N-H and N-O groups in the FTIR spectrum. The deconstruction of proteins and fatty acids present in mosquito was similar to that of microalgae in terms of the pyrolysis products.Graphical Abstract

Source: Journal of Analytical and Applied Pyrolysis - December 30, 2019 Category: Chemistry Source Type: research