Cutting-edge arsenic quantification in pyrolysis oils: evaluation of a high temperature torch integrated sample introduction system (hTISIS) combined with an ICP-MS/MS

Abstract

An innovative approach for routine arsenic quantification in complex tire pyrolysis oil (TPO) matrices by combining a high temperature torch integrated sample introduction system (hTISIS) with ICP-MS/MS is presented. Tire pyrolysis oils present significant potential as alternative fuels but require precise monitoring of arsenic due to its environmental toxicity and its detrimental effects on catalytic processes. The hTISIS system, operating at 400 °C, significantly enhanced analyte transport efficiency, increasing the signal by up to 20-fold compared to conventional sample introduction systems. Moreover, the method achieved detection limits as low as 2 ng kg⁻¹ for arsenic in xylene, significantly lower than the 20 ng kg⁻¹ obtained using conventional sample introduction systems. Moreover, procedural limit of quantification (pLOQ) obtained for the hTISIS system was 60 ng kg⁻¹. Additionally, the combination of hTISIS working at 400 °C and ICP-MS/MS successfully mitigated matrix effects and spectral interferences by employing oxygen as a reaction gas, allowing accurate quantification even in samples containing high chlorine levels. Analysis of 13 TPO samples showed arsenic concentrations ranging from 41 ± 4 to 924 ± 80 µg kg⁻¹. The results were validated through comparison with microwave digestion method, showing no statistically significant differences for most samples with a confidence level of 95%.