A green and engineered magnetic ionic liquid system for selective extraction and trace determination of thorium in industrial and environmental samples.

Abstract

Thorium contamination poses serious health and environmental risks, highlighting the need reliable detection methods. This study presents a green and engineered analytical system for the selective extraction and determination of thorium ions in ores and aqueous samples. A task-specific hydrazinium-based ionic liquid, 2-(4-hydroxybenzyl)hydrazinium chloride ([Hyim][Cl]), was synthesized and characterized using ¹HNMR, ¹³CNMR, FTIR, VSM, and CHNO analysis. The ionic liquid demonstrated strong affinity toward thorium ions and enabled efficient magnetic separation. Experimental parameters were optimized via a design of experiments (DOE) approach. Under optimal conditions, the system achieved 98.6% extraction efficiency, a detection limit of 0.11 µg/L, a quantification limit of 0.22 µg/L, a linear dynamic range of 5.0-200.0 µg/L, intra-day relative standard deviation of 2.17%, inter-day of 2.86%, preconcentration factors of 122, enrichment factor of 100 and recovery rates between 96.4 and100.5% in real water and wastewater samples.