Search

A procedure is reported for the efficient extraction and determination of phenolics from aqueous media. The approach is based on the dispersive micro-solid phase extraction using synthesized Co3O4 nanocube-functionalized nitrogen-doped melamine foam. The adsorption and desorption conditions were optimized by response surface methodology and one-variable-at-a-time approaches. The proposed method was fully validated. Under the optimized conditions, the limits of detection were lower than 0.5 ng mL−1. Calibration curves were linear in the range from 1.0 to 250.0 ng mL−1, 0.7 to 200.0 ng mL−1, 0.2 to 250.0 ng mL−1, and 1.0 to 250.0 ng mL−1 for phenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol, respectively. Enrichment factors and absolute recoveries from 17.5 to 20.7 and 70% to 83% were achieved. The method was successfully applied for trace monitoring of the analytes in environmental and industrial water samples with gas chromatography—flame ionization detection analysis. Satisfactory relative recoveries between 89.0% and 105.8% were obtained along with acceptable precision below 8.1%. This method is a simple, rapid, sensitive, and reliable protocol for efficient screening of the phenolics. [ABSTRACT FROM AUTHOR]

A modified Co3O4 nanocube-coated melamine-derived carbon sponge was synthesized and implemented for an in-syringe micro-solid-phase extraction approach as a promising sorbent. The introduced method combined with gas chromatography–flame ionization detection has been successfully developed for the determination of naphthalene, anthracene, and pyrene in environmental water samples. Significant adsorption and desorption parameters, including sorbent amount (19.0 mg), sample pH (7.4) and flow rate (233.0 µL min−1), salt concentration (20.0%), number of adsorption (4) and desorption (4) cycles, eluent volume (425.0 µL) and its flow rate (153.0 µL min−1), were optimized by the central composite design. Under the optimal conditions, the calibration curves were linear in the range of 3.0–500.0, 1.0–250.0, and 0.8–250.0 ng mL−1 for naphthalene, anthracene, and pyrene, respectively, along with acceptable intra- and inter-day precision (≤ 8.3%). The absolute recoveries were obtained in the range of 57.4–76.6%, while limits of detection were found between 0.2 and 0.8 ng mL−1. Eventually, the proposed method was successfully applied for the determination of the studied compounds in environmental and industrial water samples with satisfactory relative recoveries between 87.5 and 104.5%. The approach minimizes organic solvent consumption, sorbent amount, and sample solution volume, resulting in reasonable sensitivity and excellent reusability. This quantitative protocol is an efficient and satisfactory analytical procedure because of its high accuracy and precision. It proved to be highly cost-effective and reliable for screening purposes. [ABSTRACT FROM AUTHOR]