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In this work, a solid-phase microextraction (SPME) method combined with two-dimensional gas chromatography coupled to mass spectrometry (GC × GC-MS) was optimized and used to assess the authenticity of pomegranate juice to prevent fraudulent practices. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for the extraction of the volatiles. The critical parameters that affect the extraction process, such as the sample volume, and the extraction time were studied. The optimized protocol involved the addition of 15 mL of juice in 50 mL vial and saturation with 30% w/v NaCl.The extraction was carried out within 45 min under 1000 rpm stirring and was applied in the analysis of real juice samples to assess authenticity and detect low levels of pomegranate juice adulteration with grape and apple juice down to 1%. Commercially available pomegranate juice samples were acquired (n 1 = 6) and adulterated with 1% of apple juice (n 2 = 6), 1% of grape juice (n 3 = 6), and a mixture of 1% apple juice and 1% grape juice (n 4 = 6). Authentic pomegranate juice samples and adulterated mixtures were analyzed by SPME-GC × GC-MS. The analysis resulted in the identification of 123 volatile compounds that were further processed with chemometric tools. Principal component analysis (PCA) was employed to visualize the clustering of the samples, and a two-way orthogonal partial least squares discriminant analysis (O2PLS-DA) chemometric model was developed and successfully classified the samples to authentic pomegranate juice or adulterated with an explained total variance of 87.4%. The O2PLS-DA prediction model revealed characteristic volatile markers that could be used to detect pomegranate juice fraud. [Display omitted] • Optimized SPME method combined with GC × GC-MS to address food fraud. • 2D-GC volatilomics for the exploration of the fingerprint of juices. • Chemometrics successfully discriminated between pure pomegranate juices and adulterated. • Identification of characteristic volatile markers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design of second generation TiO 2 based FPSE membranes. • Analysis of clarified and unclarified apple juice samples. • Development of an FPSE-GC–MS method for OPPs determination. • Higher extraction efficiency for OPPs compared to their silica analogues. In this work, different sol–gel sorbent-coated second-generation fabric phase sorptive extraction (FPSE) membranes were synthesized using titania-based sol–gel precursors. The proposed membranes were tested for their efficiency to extract eleven selected organophosphorus pesticides (OPPs) from apple juice samples. Among the examined materials, sol–gel C 18 coated titania-based FPSE membranes showed the highest extraction efficiency. These membranes were used for the optimization and validation of an FPSE method prior to analysis by gas chromatography-mass spectrometry. The detection limits for OPPs ranged between 0.03 and 0.08 ng mL−1. Moreover, the relative standard deviation was < 8.2% and 8.4% for intra-day and inter-day studies, respectively. The relative recoveries were 91–110% (intra-day study) and 90–106% (inter-day study) for all the target analytes, demonstrating good overall method accuracy. Moreover, the novel membranes were reusable at least 5 times. The titania-based membranes were compared to the conventional silica-based membranes and their utilization resulted in higher extraction recoveries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Extraction of benzoyl urea pesticides using sol–gel PCAP-PDMS-PCAP capsules. • Successful application for the monitoring of pesticides in commercial apple juices. • CPME provides efficient sample clean-up and high analyte preconcentration. • The CPME-HPLC-DAD method showed good accuracy, precision, and sensitivity. • The CPME capsules are easy to fabricate, cost-effective and reusable. Fruit juices may contain harmful residues of pesticides that are associated with ecological and health risks. Thus, it is critical to develop sensitive and accurate methods for the monitoring of pesticides in these food products. In the present study, a simple and sensitive capsule phase microextraction (CPME) protocol combined with high-performance liquid chromatography-diode array detection (HPLC-DAD) was developed for the monitoring of benzoyl urea pesticides (chlorfluazuron, diflubenzuron, hexaflumuron, lufenuron, and triflumuron) in apple juices. Among the different examined sorptive phases, monolithic sol–gel poly(caprolactone)-poly(dimethylsiloxane)-poly(caprolactone) capsules were found to exhibit the highest extraction efficiency. The adsorption and desorption steps of the CPME method were optimized and the proposed method was validated. Under optimum conditions, the limits of detection for all analytes were in the range 0.15–0.30 ng mL−1. Moreover, the proposed protocol exhibited good linearity, accuracy, and precision. The relative recoveries of the method ranged between 90% and 108%, and the relative standard deviations were <8% and 9% for intra-day and inter-day precision, respectively. The ComplexGAPI index was used to evaluate the green potential of the proposed method. Finally, the proposed method was employed in the analysis of a wide variety of commercially available apple juice samples. [ABSTRACT FROM AUTHOR]