Efficient and Sensitive Detection of Organophosphate Pesticides in Orange Juice Using Dispersed Solid-Phase Extraction Based on Amorphous UiO-66

Organophosphate pesticides can cause long-term neurological damage to humans. There is an urgent need to develop a more sensitive and efficient method for detecting trace amounts of organophosphorus pesticides in orange juice, particularly in the presence of interfering substances. This study developed a dispersive solid-phase extraction (DSPE) method using amorphous UiO-66 (aUiO-66) as an adsorbent for the detection of four organophosphate pesticides (fenthion, profenofos, fensulfothion, and chlorpyrifos) in orange juice. The aUiO-66 was synthesized in a green, direct method within a deep eutectic solvent composed of diethanolamine hydrochloride and acetamide. Its amorphous nature was confirmed through x-ray diffraction (XRD) and thermogravimetric analysis (TGA). Parameters influencing extraction efficiency, including adsorbent dosage, extraction time, eluent type, and volume, were optimized by genetic neural network (GNN). The method demonstrated good linearity (R2 = 0.9927-0.9981), high recovery (95.35%-110.75%), low limit of detection (0.169-0.214 ng L⁻¹), and precision (intraday RSD = 4.13%-5.44%, interday RSD = 3.28%-4.91%). It was successfully applied to analyze targets in commercially available orange juices, detecting residues within 4.37-36.07 µg L⁻¹. This study's methodological development offers significant guidance for efficient detection of organophosphorus pesticides in food products, potentially facilitating the advancement and application of simpler and more efficient analytical techniques.

Synthesis of green nanosorbent from bovine serum albumin and curcumin for magnetic solid phase extraction of pesticides from food samples

For the first time, a magnetic carbon nanocomposite was synthesized using one-step hydrothermal procedure, employing bovine serum albumin, curcumin, and ferric ammonium citrate. Additionally, the application of this novel composite as an adsorbent for magnetic dispersive solid phase extraction of fungicides and pesticides from water and food samples is a unique aspect of this study. Under optimum conditions (salt concentration: 5.0% w/v, pH: 7.0, desorption solvent: ethanol, sorbent amount: 20 mg, extraction time: 20 min, desorption time: 3 min, stirring rate: 500 rpm, sample volume: 30 mL, extraction temperature: room temperature, and desorption solvent volume: 150 μL) linearity (2.5 to 1400 ng mL-1), coefficients of determination (R2 ≥ 0.997), limits of detection (0.75 to 1.5 ng mL-1), and limits of quantification (2.5 to 5.0 ng mL-1) were achieved. The method validation results showed extraction recovery ranging from 71.2% to 93.4%, and preconcentration factors ranging from 142.5 to 186.1.

Fast and efficient extraction and determination of nonsteroidal anti-inflammatory drugs using poly(8-hydroxyquinoline)-coated magnetic graphene oxide nanocomposite prior to capillary electrophoresis analysis in wastewater, breast milk, and urine samples

In this study, magnetic graphene oxide coated with poly(8-hydroxyquinoline) was successfully synthesized, characterized, and utilized as a novel sorbent for the ultrasonic-assisted dispersive magnetic solid-phase extraction of naproxen and ibuprofen. These analytes served as representative analytes for two nonsteroidal anti-inflammatory drugs in various real samples. Characterization techniques, such as IR, X-ray powder diffraction, field emission scanning electron microscopy, energy-dispersive X-ray-mapping, and Brunauer-Emmett-Teller (BET), were used to confirm the correctness synthesis and preparation of the nanocomposites. Effective parameters on the extraction efficiency were investigated to maximize the analytical performance of the developed method. The dynamic range (1-1000 µg L-1), coefficients of determination (R2 ≥ 0.997), the limits of detection (0.3-1.0 µg L-1), and limit of quantification (1.0-3.0 µg L-1), intra-day and inter-day precisions (3.5%-7.2%) were achieved. The method validation results showed extraction recovery ranging from 80.4% to 96.0% and preconcentration factors ranging from 137 to 140.

Dummy molecularly imprinted polymers-agarose gel mixed matrix membrane for extraction of amphetamine-type stimulants in wastewater and urine

Dummy molecularly imprinted polymers (DMIPs) with high selectivity for amphetamine-type stimulants (ATSs) were synthesized using synephrine molecule as a dummy template. The polymers were irregularly massive with a specific surface area of 330 m2g-1. Adsorption experiments found that the imprinting factors for five ATSs (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxy-N-ethylamphetamine) were 2.3∼3.7. The DMIPs-agarose gel mixed matrix membranes (MMMs) were further prepared by incorporating DMIPs in the agarose matrix. MMMs were used to extract five ATSs from wastewater and urine samples. Extraction conditions such as membrane matrix, sample pH, dissolved organic matter content, extraction time, and elution reagent were optimized. Under optimal conditions, the developed MMMs-HPLC-MS/MS method exhibited low limits of detection (0.1∼3.0ng L-1), satisfactory recoveries (91.7∼100%), and good repeatability (RSD<7%, n=3). It was then successfully applied to ATSs analysis in wastewater and urine samples. Recoveries of ATSs in spiked wastewater and urine were 82.0∼98.4% and 82.3∼95.7%, respectively. Moreover, compared with other methods, the present method possessed the advantages of high quantitative ability, suitable for typical environmental conditions, and low application cost. The above results suggested that the developed MMMs-HPLC-MS/MS method could be used as a feasible strategy to extract and determine trace ATSs in wastewater and urine samples.

Investigation of organophosphorus (OPs) compounds by a needle trap device based on mesoporous organo-layered double hydroxide (organo-LDH)

Organophosphorus (OPs) compounds can endanger human health and the environment by inhibiting the acetylcholinesterase enzyme. But these compounds have been widely used as pesticides due to their effectiveness against all kinds of pests. In this study, a Needle Trap Device (NTD) packed with mesoporous organo-layered double hydroxide (organo-LDH) material and coupled with gas chromatography-mass spectrometry (GC-MS) was employed for the sampling and analysis of OPs compounds (diazinon, ethion, malathion, parathion, and fenitrothion). In this way, the [magnesium-zinc-aluminum] layered double hydroxide ([Mg-Zn-Al] LDH) modified with sodium dodecyl sulfate (SDS) as a surfactant was prepared and characterized by FT-IR, XRD, BET, and FE-SEM, EDS, and elemental mapping techniques. Then, various parameters such as relative humidity, sampling temperature, desorption time, and desorption temperature were evaluated by the mesoporous organo-LDH:NTD method. The optimal values of these parameters were determined using response surface methodology (RMS) and central composite design (CCD). The optimal temperature and relative humidity values were obtained as 20 °C and 25.0%, respectively. On the other hand, the desorption temperature and time values were in the range of 245.0-254.0 °C and 5 min, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were reported in the range of 0.02-0.05 mg m^-3 and 0.09-0.18 mg m^-3, respectively, which shows the high sensitivity of the proposed method compared to the usual methods. The repeatability and reproducibility of the proposed method (by calculating the relative standard deviation) was estimated in the range of 3.8-10.10 which indicates the acceptable precision of the organo-LDH:NTD method. Also, the desorption rate of the stored needles at 25 °C and 4 °C, was determined to be 86.0% and 96.0%, respectively after 6 days. The results of this study proved that the mesoporous organo-LDH:NTD method can be utilized as a fast, simple, environmentally friendly, and effective method for sampling and determining OPs compounds in the air.

Integrated ultrasound-assisted magnetic solid-phase extraction for efficient determination and pre-concentration of polycyclic aromatic hydrocarbons from high-consumption soft drinks and non-alcoholic beers in Iran

In the present research, an ultrasound-assisted magnetic solid-phase extraction coupled with a gas chromatography-mass spectrometry hybrid system was developed for extraction/determination of trace amounts of polycyclic aromatic hydrocarbons in high-consumption soft drinks and non-alcoholic beers in Iran using magnetite graphene oxide adsorbent. The magnetite graphene oxide was characterized by scanning electron microscope, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer techniques. The highest extraction recovery (73.05 to 95.56%) and enrichment factor (90.65 to 106.38) were obtained at adsorbent mass: 10 mg, adsorption time: 30 min, salt addition: sodium chloride 10% w/v, desorption time: 20 min, eluent type: hexane: acetone (1:1, v/v), and desorption solvent volumes: 200 μL. Under optimum conditions, the linearity range for polycyclic aromatic hydrocarbons determination was 0.2-200 ng mL^-1  with coefficient of determination> 0.993, limit of detection = 0.09-0.21 ng mL^-1 , limit of quantitation = 0.3-0.7 ng mL^-1 , and relative standard deviation < 8.1%, respectively. Relative recoveries in spiked real samples ranged from 94.67 to 109.45 % with standard deviation < 6.05%. The proposed method is effective, sensitive, reusable and it is promising for the analysis of polycyclic aromatic hydrocarbons residues in environmental samples. This article is protected by copyright. All rights reserved.