Enrichment of pyrethroid insecticides using effervescent-assisted ionic liquid functionalized in melamine sponge for pipette tip micro solid-phase extraction

Abstract

A preconcentration and detection method using ionic liquid for embedded in melamine sponge for pipette tip micro solid-phase extraction of pyrethroid insecticides coupled to HPLC was developed for trace amount of pyrethroids residue detection. The synthesis of ionic liquid was accomplished by using tributylhexadecylphosphonium bromide ([P₄₄₄₁₂]Br) and potassium hexafluorophosphate (KPF₆), after that effervescent process was carried out by adding sodium carbonate into a centrifuge tube. The as-prepared ionic liquid was then embedded into melamine sponge, and used for pipette tip micro solid-phase extraction of insecticides in fruit juice matrices. After impregnation, the morphological and structural properties of the sorbents were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. Under the selected conditions, the method exhibited wide linear range (2 – 100 μg l^-1) with a coefficient for determination (R²) greater than 0.99. The limit of quantification (LOQ) and limit of detection (LOD) were in the range of 2 – 3 μg l^-1 and 0.7 – 1 μg l^-1, respectively. Good reproducibility (RSD < 4.65%, n = 5) were achieved. Moreover, the proposed method provided high enrichment factors (EF) ranging from 36.50 to 45.52 folds. The sorbent was then applied to extract pyrethroids in fruit juice. Accuracy was excellent and acceptable recoveries were attained. The greenness profiles were evaluated utilizing multiple assessment metrics including the Analytical Eco-Scale, AGREE Assessment, and BAGI.