Pyrolysis kinetics study of nucleic acid detection supplies

Abstract

To investigate the pyrolytic behavior of materials used in nucleic acid detection and unravel their chemical reaction mechanisms at a molecular scale, thermogravimetric experiments were conducted on a range of components: polypropylene (PP) sampling tubes, polyamide/acrylonitrile butadiene styrene (PA/ABS) pharyngeal swab sampling heads, ABS pharyngeal swab rods, and mixtures of pharyngeal swab sampling heads and sampling tubes at heating rates of 10, 20, 30, and 40°C/min employing conversion from 0.1 to 0.9 in 0.1 increments. Employing three model-free methods—Kissinger–Akahira–Sunose, (KAS) Flynn–Wall–Ozawa, and Friedman—the pyrolysis kinetics of individual components and mixtures were analyzed. The average activation energy were obtained to be 144.0–152.7, 211.4–213.5, 163.3–168.7, and 156.6–167.3 kJ/mol, respectively. Two model-fitting methods—Coats-Redfern and Criado—were used to elucidate the chemical reaction mechanisms across various heating rates and conversions. The pre-exponential factor was calculated. The pyrolytic behavior of pharyngeal swabs was simulated, and the results showed that the most accurate kinetic parameters were obtained by the KAS method.