Multivariate optimization of chlorinated hydrocarbons’ micro-solid-phase extraction from wastewater using germania-decorated mesoporous alumina-silica sorbent and analysis by GC–MS

The need for clean and accessible drinking water in several parts of the world is continuously becoming alarming due to the increased rate of industrialization that results in polluting water bodies. Chlorinated hydrocarbons (CHCs) form an important class of these pollutants. In this study, a new set of sorbents based on germania decorated mesoporous alumina-silica were utilized to extract and analyze twelve different CHCs that are usually found in wastewater bodies. The sorbents were characterized using XRD, FTIR, BET and FESEM. The extraction parameters were optimized using the Taguchi experimental design, analysis of variance (ANOVA) and signal-to-noise response. The sorbent dosage of 5 mg, extraction time of 20 min, desorption time of 20 min and methanol solvent were the optimized extraction parameters. A wide linear range of 1 – 800 ng mL⁻¹ with determination coefficient of 0.9919 – 0.9993 was observed. Detection limit (LOD) and high reproducibility (%RSD) were obtained within the ranges of 0.14 – 0.45 ng mL⁻¹ and 1.1 – 9.5% respectively. The relative recoveries from the wastewater samples were in the range 85.0 – 114%.