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A metal organic framework (MOF)-based dispersive solid phase extraction procedure was introduced using a hydrophobic sorbent for the extraction of multi class pesticides from fruit juice samples prior to their determination by high performance liquid chromatography-tandem mass spectrometry. For this purpose, NH 2 -UiO-66(Zr) MOF was synthesized by a hydrothermal approach. Then the sorbent was silylated and used in the extraction procedure. The extraction procedure was done by using 7 mg of the sorbent from 5 mL of a sample solution containing the analytes. After that, the extracted analytes were eluted and preconcentrated by vaporizing the elution solvent. The method was linear within the range of 0.29–500 ng mL−1. The limits of detection, intra- and inter-day relative standard deviations, and extraction recoveries were in the ranges of 0.02–0.1 ng mL−1, 2.9–8.8%, 6.8–14.4%, and 74–89%, respectively. Performing the method on the selected samples showed that they were free of the analytes. This method can help to monitor the studied pesticides in juice samples as well as improving the safety of foods. • A hydrophobic MOF was synthesized and used in extraction procedure. • DSPE method was developed for extraction of pesticides from fruit juices. • HPLC-MS/MS method was used for determination of pesticides. • Low cost, easiness, and effective sample preparation were advantages of the method. [ABSTRACT FROM AUTHOR]

In this work, an efficient magnetic sorbent has been prepared using the extract of Tanacetum leaves and used in magnetic dispersive solid phase extraction of Cu(II) and Pb(II) ions from high volume of milk samples performed in a narrow-bore tube. For this purpose, first, the sorbent was prepared by mixing Fe 3 O 4 magnetic nanoparticles and Tanacetum leaves extract. After precipitation of the milk proteins with trichloroacetic acid, the sedimented compounds were removed and the upper solution was filled into the narrow-bore tube. Then after that, the mg-level of the prepared sorbent was added. After doing the extraction procedure, the sorbent particles were removed from the tube in the presence of a magnetic field. The adsorbed analytes were desorbed by methanol and to achieve low detection limits, the eluent obtained from the first step was subjected to dispersive liquid-liquid microextraction. Finally, the enriched analytes were monitored by flame atomic absorption spectrometry. The important parameters affecting the method efficiency such as the sorbent amount, type and volume of elution and extraction solvents, vortex time, pH, and ionic strength were studied. Under optimized conditions, the proposed method showed linear ranges of 0.50–40 and 0.75–40 µg L−1 for Cu(II) and Pb(II) ions, respectively. Limits of detection were obtained 0.16 and 0.22 µg L−1 for Cu(II) and Pb(II), respectively. Enrichment factors of 182.5 and 173.7 and extraction recoveries of 95.8 % and 91.2 % were obtained for Cu(II) and Pb(II), respectively. The relative standard deviations (intra- and inter-day precisions) for 5 and 25 µg L−1 of each cation were between 2.4 % and 4.3 %. • Tanacetum extract was used for functionalisation of Fe 3 O 4. • The prepared MNPs was used for the extraction of heavy metals from milk. • The MDSPE was combined with a dispersive liquid-liquid microextraction procedure. • The method has low LODs and LOQs, high EFs and ERs. [ABSTRACT FROM AUTHOR]

• An efficient reversed-phase DLLME using a synthesized DES is proposed. • The DES was used for the first time as a disperser solvent in RP-DLLME. • It is the first report on the application of the present method in oily samples. A new, sensitive, and safe pretreatment method for the analysis of Cd(II) and Zn(II) ions in oil samples prior to flame atomic absorption spectrometry was developed. For the first time, a deep eutectic solvent is used as a disperser in reversed-phase dispersive liquid-liquid microextraction procedure. For this purpose, a deep eutectic solvent with low viscosity and miscible with both aqueous and organic phases is prepared by mixing glycolic acid and mandelic acid at a molar ratio of 2:1. The variables involved in this process were studied to provide high enrichment factors. Under optimized conditions, the linear ranges of calibration curves for Cd(II) and Zn(II) ions were obtained 0.30−20 and 0.50−30 μg L−1, respectively. The obtained detection limits and enrichment factors were 0.12 and 0.18 μg L−1; and 32.7 and 32.2 for Cd(II) and Zn(II), respectively. Repeatability of the proposed method, expressed as relative standard deviation, ranged from 2.7 to 4.1 % (n = 6, C = 1 μg L−1 of each cation). Finally, the proposed method was successfully applied for the determination of Cd(II) and Zn(II) concentrations in various oil samples. [ABSTRACT FROM AUTHOR]

In this study, a simple and sensitive analytical method was developed for the determination of some heavy metal ions in aqueous samples using inductively coupled plasma-optical emission spectrometry. In this method, firstly, cobalt ferrite nanoparticles were synthesized before they were functionalized with a deep eutectic solvent. The used functionalization solvent was prepared by mixing choline chloride and p -aminophenol. The obtained new nanoadsorbent was used for the extraction of Zn(II), Ni(II), Cu(II), Pb(II), and Hg(II) from the sample solutions by dispersive micro solid phase extraction. The effect of some important parameters such as the sorbent amount, ionic strength, pH, agitation mode and time, and elution solvent type and volume on the extraction efficiency of the method was investigated. Broad linear ranges (1.83–200 ng mL−1) with low limits of detection in the range of 0.54–1.3 ng mL−1 were obtained. The accuracy of the developed method was investigated by determination of the analytes in a certified reference material (SPS-WW2 Batch 108 water). The extraction recoveries of the analytes were obtained in the range of 72–90%. Finally, the developed method was successfully applied to determine the selected ions in different water and fruit juice samples, and the relative recoveries were obtained in the range of 85–104%. • Cobalt ferrite nanoparticles were functionalized with a deep eutectic solvent. • A green solvent instead of toxic and expensive reagents was used for modification. • The sorbent was used for the extraction of Zn, Ni, Cu, Pb, and Hg. • Using low amount of sorbent and low LODs were important features of the method. [ABSTRACT FROM AUTHOR]