Determination of Cadmium in Fruit and Vegetables by Ionic Liquid Magnetic Microextraction and Flame Atomic Absorption Spectrometry

g-C3N4@TiO2@Fe3O4 Multifunctional Nanomaterial for Magnetic Solid-Phase Extraction and Photocatalytic Degradation-Based Removal of Trimethoprim and Isoniazid

In this period when environmental pollution has become uncontrollable, the removal of drug active substances reaching the environment and the analysis of drug active substances in different matrix environments are important for both living life and a sustainable environment. Therefore, the production of multifunctional materials that can be used in these two different processes has gained importance in the literature. Based on this thought, in this study, a g-C₃N₄@TiO₂@Fe₃O₄ multifunctional nanohybrid material was synthesized and used for magnetic solid-phase extraction (MSPE) and photocatalytic degradation of trimethoprim and isoniazid, used together in tuberculosis treatment. All analyses were performed by high-performance liquid chromatography using a diode-array detection (HPLC-DAD) system. The synthesized material was characterized by X-ray diffraction spectroscopy (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) method, ζ-potential analysis, field-emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDX). Important analytical parameters for the MSPE method such as the pH value of the sample solution, the volume of the sample solution, the amount of the sorbent, the type and volume of the elution solvent, and extraction time were optimized. The optimized MSPE method was then applied to different environmental waters and pharmaceutical samples. The recovery percentages for these samples were found to be between 95 and 107%. For trimethoprim and isoniazid, the limit of detections (LODs) were 0.055 and 0.145 and the limit of quantifications (LOQs) were 0.167 and 0.439 ng·mL^-1, respectively. It was observed that ∼100% of trimethoprim and isoniazid active components were photocatalytically removed from the g-C₃N₄@TiO₂@Fe₃O₄ nanohybrid material in ∼120 min under UV light.

Ionic Liquid-Assisted DLLME and SPME for the Determination of Contaminants in Food Samples

Developing effective and green methods for food analysis and separation has become an urgent issue regarding the ever-increasing concern of food quality and safety. Ionic liquids (ILs) are a new chemical medium and soft functional material developed under the framework of green chemistry and possess many unique properties, such as low melting points, low-to-negligible vapor pressures, excellent solubility, structural designability and high thermal stability. Combining ILs with extraction techniques not only takes advantage of ILs but also overcomes the disadvantages of traditional extraction methods. This subject has attracted intensive research efforts recently. Here, we present a brief review of the current research status and latest developments regarding the application of IL-assisted microextraction, including dispersive liquid–liquid microextraction (DLLME) and solid-phase microextraction (SPME), in food analysis and separation. The practical applications of ILs in determining toxic and harmful substances in food specimens with quite different natures are summarized and discussed. The critical function of ILs and the advantages of IL-based microextraction techniques over conventional extraction techniques are discussed in detail. Additionally, the recovery of ILs using different approaches is also presented to comply with green analytical chemistry requirements.

Ultrasound-Assisted Ionic Liquid Microextraction for Preconcentration of Cadmium in Water, Vegetables and Hair Samples Prior to FAAS Determination

Background::

Cadmium (Cd2+) is considered to be one of the most important hazardous heavy metals due to its toxicity for living organisms at low concentration levels. Therefore, the estimation of trace Cd2+ in different types of various samples is a very important objective for chemists using effective methods. In the present work, a novel, green, easy and fast ultrasoundassisted ionic liquid-dispersive liquid phase microextraction technique (UA-IL-DLPME) was developed to preconcentrate and determine trace quantities of cadmium (Cd2+) ions from real samples, prior to detection by FAAS.

Methods:

The proposed technique is based on utilization of ionic liquid (IL) (1-hexyl-3- methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for Cd2+ ions after complexation with 2-(6-methylbenzothiazolylazo)-6-nitrophenol (MBTANP) at pH 7.0. The impact of different analytical parameters on the microextraction efficiency was investigated. The validation of the proposed procedure was verified by the test of two certified reference materials (TMDA-51.3 fortified water, SRM spinach leaves 1570A) applying the standard addition method.

Results:

In the range of 2.0-200 μg L−1, the calibration graph was linear. Limit of detection, preconcentration factor and the relative standard deviation (RSD %, 100 μg L-1, n=5) as precision was 0.1 μg L-1, 100 and 3.1%, respectively.

Conclusion:

Green UA-IL-DLPME method was developed and applied to preconcentrate and determine trace quantities of Cd2+ in real water, vegetables and hair samples with satisfactory results.

A new strategy for the combination of supramolecular liquid phase microextraction and UV-Vis spectrophotometric determination for traces of maneb in food and water samples

A novel and green method was developed for enrichment of maneb (manganese ethylene-bisdithiocarbamate) with a supramolecular solvent liquid phase microextraction method. The microextraction method has been used for the first time in the literature for separation-preconcentration of maneb. 1-decanol and tetrahydrofuran were used in the supramolecular solvent formation. The Mn²⁺ content of maneb was extracted in the supramolecular solvent phase as 1-(2-pyridylazo)-2-naphthol complex at pH 12.0. Manganese concentration was determined by UV-Vis spectrophotometer at 555 nm. Then, the maneb concentration equivalent to manganese concentration was calculated. The analytical parameters which effective in the method, including pH, volume of reagents, and sample volume were optimized. The limit of detection and the limit of quantification values for maneb were calculated as 2.22 μg L^-1 and 7.32 μg L^-1, respectively. The method was successfully applied in the analysis of the maneb content of water and food samples.

Risk of cadmium, lead and zinc exposure from consumption of vegetables produced in areas with mining and smelting past

The study reveals links between disturbed geochemical environment being the result of mining and smelting activities with consumers exposure to toxic and carcinogenic metallic trace elements (MTEs). This study focused on evaluation on vegetable and soil pollution in family allotment gardens (FAGs), considering in the aspects of consumer exposure to cadmium, lead and zinc. Study material consisted of 219 soil samples from FAGs located in one of the most polluted areas in Poland, and 64 samples of edible plants. Contents of analyzed MTEs in topsoil in the studied area were spatially diversified and depended primarily on the location of industrial pollution sources. The average content of cadmium (0.52 mg kg-1 fresh weight) and lead (0.57 mg kg-1 fresh weight) in vegetables exceeded maximum permissible concentrations according to the European Quality Standards. Human health risk assessment was based on three scenarios of dietary exposure to cadmium, lead and zinc. In every scenario the highest average daily dose for all three elements was estimated for potatoes which are one of the main components of Poles' diet. Presented study showed that consumption of vegetables cultivated in FAGs located in Silesia Province may pose a significant health risk for their consumers.

Magnetic Particles-Based Analytical Platforms for Food Safety Monitoring

Magnetic nanoparticles (MNPs) have attracted growing interest as versatile materials for the development of analytical detection and separation platforms for food safety monitoring. This review discusses recent advances in the synthesis, functionalization and applications of MNPs in bioanalysis. A special emphasis is given to the use of MNPs as an immobilization support for biomolecules and as a target capture and pre-concentration to increase selectivity and sensitivity of analytical platforms for the monitoring of food contaminants. General principles and examples of MNP-based platforms for separation, amplification and detection of analytes of interest in food, including organic and inorganic constituents are discussed.

Maghemite nanoparticle-decorated hollow fiber electromembrane extraction combined with dispersive liquid-liquid microextraction for determination of thymol from Carum copticum

BACKGROUND

A novel technique using maghemite nanoparticle-decorated hollow fibers to assist electromembrane extraction is proposed. Electromembrane extraction combined with dispersive liquid-liquid microextraction (EME-DLLME) was applied for the extraction of thymol from Carum copticum, followed by gas chromatography with flame ionization detection (GC-FID).

RESULTS

The use of maghemite nanoparticle-decorated hollow fibers was found to improve the extraction efficiency of thymol significantly. Important operational parameters, including pH of acceptor phase, extraction time, voltage and temperature, were investigated and optimized. At the optimal conditions, linearity in the range 4-1800 µg L^-1 with a determination coefficient of 0.9996 was obtained. The limit of detection was 0.11 µg L^-1 (S/N = 3) and the pre-concentration factor was 200. The intra- and inter-day precision was 5.9 and 2.2% respectively. The intra- and inter-day accuracy was higher than 93.6%.

CONCLUSION

The results indicated that EME-DLLME/GC-FID is a useful technique for the extraction and determination of thymol in C copticum. © 2016 Society of Chemical Industry.

Seasonal variations in the blood concentration of selected heavy metals in sheep and their effects on the biochemical and hematological parameters

The main objective of this study was to assess the concentration of various heavy metals (Cd, Pb, Zn, Cu, Hg) in the blood of sheep, followed by biochemical and hematological analysis in order to reveal possible associations. Blood was collected in two different seasons: winter (fed by fodder) and spring (grazing animals). The higher concentrations of Pb (p < 0.01), Cu (p < 0.05) and Hg, but lower of Cd and Zn were found in spring. Evaluation of the biochemical and hematological parameters during different seasons showed a possible environmental effect on the health of animals. A statistically significant increase of Ca (p < 0.001), Mg (p < 0.05), urea (p < 0.001), TP (p < 0.05), glucose (p < 0.01), AST (p < 0.001), ALT (p < 0.001), ALP (p < 0.01), cholesterol (p < 0.001), bilirubin (p < 0.05), triglycerides (p < 0.001) and a decrease of P (p < 0.05), HGB (p < 0.05), MCHC (p < 0.05) and RDWc (p < 0.05) in spring was detected. The results of this study showed statistically significant correlations between Pb and ALP (r = 0.53) level in winter and between Pb and Ca (r = -0.73) in the spring. The hematological analysis revealed a significant correlation between Zn and RBC (r = 0.61), MCV (r = -0.74), MCH (r = -0.71) and between Pb and MCH (r = -0.55), PCT (r = -0.66), PDWC (r = -0.55) in the winter. A high positive significant correlations were found between Cd and RDWC (r = 0.77) and Cu and RDWC (r = 0.75). The significance of this work is the use the data in the preventive diagnosis of metabolic and production diseases. The collected data may serve as a control indicator to detect toxic hazards related to the heavy metal occurrence on animal health status.