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A cold-induced homogenous liquid–liquid microextraction method combined with solidification of floating organic droplets effervescent-assisted dispersive liquid–liquid microextraction has been deve...

A cold-induced-homogeneous liquid–liquid extraction method combined with deep eutectic solvent-based dispersive liquid–liquid microextraction has been done to extract several endocrine disrupting compounds (phenol, p-chlorophenol, p-nitrophenol, octylphenol, methyl paraben, ethyl paraben, butyl paraben, and bisphenol A) and hydroxymethylfurfural from honey samples before their determination by gas chromatography–mass spectrometry. In this method, two ternary deep eutectic solvents including tetrabutyl ammonium chloride: dichloroacetic acid: ethylene glycol (hydrophilic) and tetrabutyl ammonium chloride: dichloroacetic acid: decanoic (hydrophobic) acid deep eutectic solvents are prepared and used as the extraction solvents in the developed method. The analytes are extracted by a two-step extraction procedure in which they are first extracted into the hydrophilic deep eutectic solvent and then transferred into a few microliters of the hydrophobic deep eutectic solvent for more concentration. In both steps, phase separation is done by centrifugation at low temperature. The method was optimized and validated and the results showed that the method had low limits of detection (0.21–0.50 ng g−1) and quantification (0.72–1.7 ng g−1), wide liner ranges, and an acceptable repeatability (relative standard deviation≤12). Lastly, the developed method was applied on different honey samples and bisphenol A, p-nitrophenol, and hydroxymethfurfural were found in some of them.

Evaluation of sonication energy effect on in-situ synthesis of deep eutectic solvent-based liquid phase microextraction process was performed in fresh fruit samples for extraction of five neonicoti...

In present work, an efficient, reliable and accurate analytical method has been used for the extraction of five organophosphorus pesticides (diazinon, chloropyrifos, phosalone, parathion-methyl and...

A rapid, efficient and reliable microwave-assisted homogenous liquid–liquid microextraction method has been developed for the extraction of pyrethroid pesticides from fresh fruit and vegetable samp...

A microwave-assisted quick-easy-cheap-effective-rugged-safe method based on deep eutectic solvent was combined with lighter than water organic solvent-based-dispersive liquid–liquid microextraction...

Simultaneous extraction and preconcentration of five endocrine disrupting compounds including di-butyl phthalate, di-iso-nonyl phthalates, di-ethylhexyl phthalate, di-ethylhexyl adipate, and bisphenol A from cheese have been developed using pressurized liquid extraction combined with dispersive liquid–liquid extraction followed by high-performance liquid chromatography-diode array detector. In this method, initially, the analytes are extracted into a water-miscible extraction solvent (acetone) at high pressure (1000 psi) and temperature (70 °C) in the presence of carbon tetrachloride as a modifier. After extraction, a volume of the organic phase is removed and dispersed into deionized water. The cloudy solution was centrifuged, and the sedimented phase is used in analysis. Efficient parameters were optimized using one-parameter-at-one-time strategy, and low limits of detection and quantification in the ranges of 0.82–3.1 and 2.8–10 ng g−1 were obtained, respectively. Relative standard deviations lower than 8% show an acceptable precision for the present method. The enrichment factors and extraction recoveries in the ranges of 259–319 and 78–96% were achieved, respectively. Lastly, some real samples were analyzed and di-butyl phthalate and di-ethylhexyl phthalate were found in them.

A new liquid-liquid microextraction approach by applying a deep eutectic solvent was adopted for the extraction of four antibiotics (penicillin G, dihydrostreptomycin, enrofloxacin, and ciprofloxacin) from honey samples. The enriched analytes were analyzed by HPLC-MS/MS. The procedure was carried out by synthesis of tetrabutylammonium chloride: p-cresol deep eutectic solvent in the sample solution and then its decomposition in the presence of an acid. In-solution formation of deep eutectic solvent provided wide contact areas among the extractant and sample solution, and accelerated sample preparation. Also, its decomposition enabled collection of the final extraction phase without centrifugation. Low LODs (0.55–0.79 ng/g) and LOQs (1.9–2.6 ng/g), high ERs (70–92%), and suitable RSDs (≤ 6.9%) were obtained. After performing the method on real samples, dihydrostreptomycin was found in several honey samples.

A dispersive solid phase extraction method was combined with deep eutectic solvent–based solidification of floating organic drop–dispersive liquid–liquid microextraction and used for the extraction/preconcentration of some organophosphorus pesticides residues from edible oil samples. The extracted analytes were quantified with gas chromatography–nitrogen phosphorous detector. In this procedure, the sample lipids are saponified with a sodium hydroxide solution and then the analytes are adsorbed onto a primary secondary amine sorbent. After that the analytes are desorbed with acetone as an elution/dispersive solvent and mixed with choline chloride: 3,3–dimethyl butyric acid deep eutectic solvent and the mixture is rapidly dispersed into deionized water. Then, the obtained cloudy solution is centrifuged and placed into an ice bath. The extraction solvent is solidified on the top of the solution. Finally, it is removed and dissolved in acetonitrile, and 1 µL of the solution is injected into the separation system. Validation of the method showed that limits of detection and quantification were in the ranges of 0.06–0.24 and 0.20–0.56 ng mL–1, respectively. Enrichment factors and extraction recoveries of the analytes ranged from 170–192 and 68–77%, respectively. The method had an acceptable precision with relative standard deviations less than ≤9.2% for intra– (n=6) and inter–day (n=6) precisions at four concentrations (3, 10, 50, and 250 ng mL–1, each analyte). Finally the method was used for determination of the analytes in five edible oil samples.

Enterococcus spp. were isolated from Motal cheese (a traditional raw milk cheese in Iran) and some probiotic and safety properties were evaluated. Ten of the 52 isolated enterococci showed ideal survival rates under the simulated gastrointestinal tract and were therefore selected for further analysis. Based on the results, six out of ten tested isolates belonging to Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus avium and Enterococcus durans did not demonstrate the incidence of any major virulence factor, haemolytic activity or resistance to most of the antibiotics studied, especially vancomycin. Moreover, these six isolates inhibited the growth of Listeria monocytogenes, had adhesion ability to epithelial cells and showed high cholesterol assimilation and good auto-aggregation activities. The bottom line is that some naturally occurring Enterococcus strains isolated from Iranian Motal cheese have the potential to be used in functional food formulations due to their probiotic properties and safety.

A sensitive, rapid, and efficient analytical method based on vortex-assisted liquid–liquid extraction combined with air-assisted liquid–liquid microextraction using high performance liquid chromatography-variable wavelength detection has been developed for the extraction and determination of bisphenol A and bisphenol B in canned doogh samples. In this method, the analytes are partitioned into n-hexane during liquid–liquid extraction and then they are enriched using the following air-assisted liquid–liquid microextraction procedure in a few microliters of an ammonia solution used as an extraction solvent. Under the optimum conditions, limits of detection and quantification were 0.82 and 0.54 and 2.7 and 1.5 ng mL−1, for bisphenol A and bisphenol B, respectively. The extraction recoveries and enrichment factors of the selected analytes were 86 and 81% and 4300 and 4050, respectively. The relative standard deviations were lower than 9% for intra- (n = 6) and inter-day (n = 4) precisions at a concentration of 5 ng mL−1 of each analyte. Finally, some canned doogh samples were effectively analyzed by the proposed method.

An organic solvent-free extraction procedure using elevated temperature liquid–liquid extraction/ dispersive liquid–liquid microextraction based on deep eutectic solvent has been performed for the extraction of three synthetic phenolic antioxidants from oil samples. In the developed approach, firstly the antioxidants were extracted into an aqueous alkaline solution in an elevated temperature. Then, a few microliters of deep eutectic solvent formed from tetrabutylammonium chloride and hydroquinone was dissolved in the alkaline solution and a homogenous solution was obtained. In the following it was dispersed into an acidic solution. In this step, an acid–base reaction was occurred and the analytes were migrated into the fine droplets of the deep eutectic solvent. The extracted analytes were determined by gas chromatography-flame ionization detector. Validation data showed that low limits of detection (0.13–0.42 ng/mL) and quantification (0.36–1.41 ng/mL), high extraction recovery (74–89%) and enrichment factor (370–445), and good precision (relative standard deviation ≤ 7.4%) can be obtained by the developed method. Finally, the method was used for quantification of the antioxidants in several edible oil samples.

CFU/g. Also 84 (42%) of contaminated cheese samples had positive results for faecal coliform bacteria. The results of bacteriological tests indicated that all the examined cheese samples were absent from Salmonella spp. This study revealed the low hygienic quality of local cheese produced in Sarab city. Therefore consumption of this type of cheese may lead to potential hazards for human health which must be considered by health organizations in Iran.