In situ synthesis of metal organic framework-199 on cellulose paper for extraction of selected parabens from different types of fruit juices, honey samples and cosmetics through flow injection analysis

This study presents a novel and highly efficient thin film microextraction-flow injection ‎analysis (TFME-FIA) method utilizing a metal organic framwork-199 (MOF-199)/cellulose paper composite, coupled with high-performance liquid chromatography-UV ‎‎‎(HPLC-UV) ‎ detection. To the best of our knowledge, this is the first report describing the application of a MOF-199-coated thin film directly integrated into an FIA system for the determination of parabens. The TFME-FIA-HPLC-UV method provides a rapid, cost-effective, and environmentally friendly approach for the determination of parabens in different types of fruit juices, honey samples and cosmetics. ‎‎‎Under optimized conditions, the linear concentration ranges for methylparaben and propylparaben were 0.5-200 and 1.0- 500 µg L -1 , with coefficients of determination (R 2 ) of‎ 0.9983 and 0.9990, respectively. The limits of detection (LODs) were 0.14 and 0.32 µg L -1 for methylparaben and propylparaben, respectively, while the corresponding limits of quantification ‎‎(LOQs) were ‎‎0.14 and 0.46 µg L -1 and 1.0 µg L -1 . The method demonstrated good precision with relative standard ‎deviation (RSD%) values ranging from 4.29‎% to 5.84%. The synergistic effect of TFME and the semi-automated FIA system resulted in enrichment factor (EF) ‎ranging from 83 and 89 for methylparaben and propylparaben, respectively. Batch-to-batch reproducibility for three different films ranged from 5.8-6.3%. Considering the excellent performance characteristics demonstrated for the selected model parabens, which are widely used in commercial products, the proposed method can be regarded as a robust and reliable analytical system for the determination of various parabens in complex matrices, including food and cosmetic samples. • A novel MOF-199 sorbent via in-situ synthesis on cellulose paper • MOF-199 provides high stability and superior extraction capacity for parabens • This extraction phase was prepared in a specific pattern to be placed in the syringe filter • TFME coupled with FIA allow rapid, automated, and efficient extraction • High sensitivity due to excellent enrichment and minimal solvent consumption