HF-MMLLE USING NATURAL DEEP EUTECTIC SOLVENTS FOR DETERMINATION OF POTENTIAL LUNG CANCER BIOMARKERS IN URINE

This work expands the use of a natural deep eutectic solvent (NADES) as an alternative extractor solvent for organic solvents. Hollow fiber-microporous membrane liquid-liquid extraction (HF-MMLLE) coupled to the 96-well plate system was employed for the determination of hexanal and heptanal in urine samples. The NADES used as the extractor solvent consisted of dodecanoic acid:hexanoic acid (1:3, molar ratio). Method optimization was carried out using univariate and multivariate approaches. Extractions were performed for 60 min, followed by 30 min of derivatization reaction with 2,4-dinitrophenylhydrazine (DNPH) and buffer solution in 1:30 molar ratio (aldehyde:DNPH). The sample pH was maintained at 6.0. Desorption was performed using a mixture of acetonitrile:methanol (1:1, v/v) for 5 min. The method achieved an average throughput of approximately 1 min preparation time per sample, considering the parallel processing of 96 samples. The analytical parameters were evaluated through calibration curves with coefficients of determination (R²) of 0.9973 for hexanal and 0.9935 for heptanal. The limits of quantification (LOQ) were 100 μg L^-1 for hexanal and heptanal. Intraday and interday precision ranged from 9% to 20% and 15% to 22%, respectively. The relative recovery varied from 61.8% to 118.6%. The proposed method integrates the advantages of NADES with membrane-based extraction, resulting in a more sustainable, low-solvent and high-throughput analytical strategy for the determination of biomarkers of aldehydes in urine. The implementation of a 96-well plate configuration enables the simultaneous processing of multiple samples, improving analytical sample throughput and operational efficiency.