Determination Of Methyl Parathion Research Articles

Facile synthesis of β-cyclodextrin decorated Super P Li carbon black for the electrochemical determination of methyl parathion

ABSTRACT Herein, a novel electrochemical sensor was designed for the sensitive determination of methyl parathion (MP) using the Super P Li carbon black@β-cyclodextrin (SPLCB@β-CD) decorated glassy carbon electrode (GCE). SPLCB with high electroactive area exhibited exceptional conductivity and good dispersive property, which is beneficial for forming the interlinked conductive network structure. β-CD could not only promote the uniform dispersion of SPLCB but also effectively realise the enrichment of MP molecules. Moreover, the existence of SPLCB could make up for the defect of poor conductivity of β-CD. Under the optimal experimental condition (pH = 7.0, enrichment time: 60 s). The collaborative cooperation of SPLCB and β-CD achieved the excellent MP detection property (LOD: 8.6 nM; concentration range: 0.01–10 μM). The SPLCB@β-CD/GCE sensor exhibited acceptable repeatability and reproducibility. In addition, the proposed sensor was successfully employed to detect MP in apple juice (Recoveries: 98.0–98.6%, RSD values: 3.68–4.63%).

UiO-66 derived nanoporous carbons/electrochemically reduced graphene oxide nanocomposites-based non-enzyme electrochemical sensor towards highly efficient determination of methyl parathion in food samples

UiO-66 derived nanoporous carbons/electrochemically reduced graphene oxide nanocomposites-based non-enzyme electrochemical sensor towards highly efficient determination of methyl parathion in food samples

Highly sensitive electrochemical determination of methyl parathion based on Ketjenblack carbon@cerium dioxide nanocomposite with pearl chain–like carbon conductive network

Highly sensitive electrochemical determination of methyl parathion based on Ketjenblack carbon@cerium dioxide nanocomposite with pearl chain–like carbon conductive network

A sensitive electrochemical sensor based on the expired soybean-derived porous carbon for the determination of methyl parathion

In this work, a sensitive electrochemical sensor was designed by using the expired soybean-derived porous carbon (ESBPC) as electrode sensitizer, which was used to modify the glassy carbon electrode (GCE). The fabricated ESBPC/GCE sensor was successfully applied for the electrochemical detection of methyl parathion (MP). ESBPC was prepared by hydrothermal carbonization followed with high temperature potassium hydroxide (KOH) activation process. The obtained ESBPC sample presented obvious porous morphology, which could contribute to the improvement of charge transfer efficiency due to the interconnected porous carbon structure. Moreover, the porous morphology significantly increased the specific surface area of ESBPC, which promoted the improvement of adsorption capacity of carbon material towards MP molecules. As a result, the ESBPC sample presented high electrical conductivity and good adsorption capacity, which contributed to the improvement of electrochemical sensing performance. When used for the detection of MP, the ESBPC/GCE sensor presented sensitive MP determination performance with low limit of detection (LOD) of 11.7 nM (MP concentration: 0.05–10 μM). The DPV curve of ESBPC/GCE sensor showed obvious characteristic cathodic peak at − 0.12 V (vs. Ag/AgCl). The low relative standard deviation (RSD) of 0.6–1.2% could be obtained for the reproducibility and repeatability measurements, suggesting the good reproducibility and repeatability of the fabricated ESBPC/GCE sensor. In addition, the good anti-interference performance could be achieved with low RSD value of 2.6% at the ESBPC/GCE sensor.

Determination of parathion-methyl in water, juice, tea, and vinegar using cyclodextrin-based dispersive liquid-liquid microextraction combined with smartphone digital image colorimetry

ABSTRACT A pre-treatment and analytical procedure for parathion-methyl (PM) in food samples was developed using cyclodextrin-based dispersive liquid-liquid microextraction (CD-DLLME) accompanied by a smartphone digital image colorimetry (SDIC). The extractant used was a green deep eutectic solvent synthesised from hexanoic acid and menthol. Cyclodextrin aqueous solutions were used as the green dispersion solvents to complete the dispersion and extraction process. Thus, a simple, fast, and environmentally friendly pre-treatment method was proposed. PM that was hydrolysed to a yellow product under an alkaline environment, and the colour intensity could be obtained using a smartphone for analysis. PM showed linearity ranging from 0.0020 to 1.0000 mg L−1, with limits of quantification and detection of 0.0020 and 0.0006 mg L−1. This method has been successfully applied in water, juice, tea, and vinegar, with recoveries ranging from 80.4 to 105.7% and relative standard deviation between 1.3 and 3.6%. This method can determine the concentration of PM in different food samples.

Rapid and sensitive detection of methyl parathion in rice based on carbon quantum dots nano-fluorescence probe and inner filter effect

A highly sensitive fluorescent sensing system of novel carbon quantum dots nano-fluorescent probe based on corn stalks was established for the determination of methyl parathion by alkaline catalytic hydrolysis and inner filter effect mechanism. The carbon quantum dots nano-fluorescent probe was prepared from corn stalks using an optimized one-step hydrothermal method. The detection mechanism of methyl parathion was revealed. The reaction conditions were optimized. The linear range, sensitivity and selectivity of the method were evaluated. Under the optimal conditions, the carbon quantum dots nano-fluorescent probe exhibited high selectivity and sensitivity to methyl parathion, achieving a linear range of 0.005–14 µg/mL. The fluorescence sensing platform was applied to the detection of methyl parathion in rice samples, and the results showed that the recoveries range from 91.64 to 104.28 %, and the relative standard deviations were less than 4.17 %. The detection limit for methyl parathion in rice samples was 1.22 µg/kg, and the limit of quantitation (LOQ) was 4.07 µg/kg, which was very satisfactory.

Improved charge-transfer resonance in graphene oxide/ZrO2 substrates for plasmonic-free SERS determination of methyl parathion

This work reports a sensitive SERS substrate based on graphene oxide (GO) and quantum-sized ZrO2 nanoparticles (GO/ZrO2) for label-free determination of the organophosphate pesticide methyl parathion (MP). The enhanced light-matter interactions and the consequent SERS effect in these substrates resulted from the effective charge transfer (CT) mechanism attributed to synergistic contributions of three main factors: i) the strong molecular adherence of the MP molecules and the ZrO2 surface which allows the first layer-effect, ii) the relatively abundant surface defects in low dimensional ZrO2 semiconductor NPs, which act as intermediate electronic states that reduce the large bandgap barrier, and iii) the hindered charge recombination derived from the transference of the photoinduced holes to the GO layer. This mechanism allowed an enhancement factor of 8.78 × 104 for GO/ZrO2-based substrates, which is more than 5-fold higher than the enhancement observed for platforms without GO. A detection limit of 0.12 μM was achieved with an outstanding repeatability (variation ≤4.5%) and a linear range up to 10 μM, which is sensitive enough to determine the maximal MP concentration permissible in drinking water according to international regulations. Furthermore, recovery rates between 97.4 and 102.1% were determined in irrigation water runoffs, strawberry and black tea extracts, demonstrating the reliability of the hybrid GO/ZrO2 substrate for the organophosphate pesticides quantification in samples related to agri-food sectors and environmental monitoring.

DETERMINATION OF METHYL PARATHION IN VEGETABLES BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Organophosphorus pesticides are one of the most widely used insecticides, which are mainly used in grain, vegetables and fruits. Methyl parathion is a kind of organophosphorus pesticide, which belongs to nerve agent. It can cause different degrees of poisoning to human and livestock and cause serious environmental pollution. Therefore, it is of great significance to establish an effective method for detecting methyl parathion residues in agricultural products. The determination of methyl parathion is often carried out by gas chromatography, but because of the strong polarity and thermal instability of methyl parathion, gas chromatography brings certain difficulty. The High Performance Liquid Chromatography (HPLC) method was researched for the testing of Methyl Parathion residues in vegetables, and the chromatographic conditions for sample extraction, purification and detection were screened and optimized. In vegetables, the matrix is complex, the pesticide residue is low, and there are many interference factors. The main residual components are not easy to separate, enrich and purify, so the detection of related pesticides is not accurate. After lots of experimental exploration, the chromatographic conditions by acetonitrile extraction agent, methanol:water (73:27) as mobile phase and UV detection wavelength choosing 270 nm was selected finally. What’s more, QuEChERS (Quickly, Easy, Cheap, Effective, Rugged, Safe) method, a new pretreatment technology for pesticide residue detection in agricultural products developed in the world recent years, was used for pretreatment of three kinds of vegetables, and PSA and GCB were selected as purifying agents for sample pretreatment ultimately. The experimental results displayed that the chromatographic peak area of Methyl Parathion exhibiting a good linear relationship with its concentration in the 0.05 μM~20 μM range, and the standard curve equation is Y=4833.5x-32.64, the correlation coefficient is 99.96%. The average recoveries of Methyl Parathion in three kinds of vegetables (Lettuce, Cucumber and tomato) were between 87.38% and 114.12% at the three spiked levels of 0.5, 2 and 8μM, and the relative standard deviation (RSD) was between 1.72% and 6.2%. This method has the good points of simple operation, accurate and reliable, and is suitable for the detection of MP pesticide residues in various vegetables.

An l-cysteic acid-modified screen-printed carbon electrode for methyl parathion determination

This work demonstrates the development and validation of a non-enzymatic sensor consisting of an l-cysteic acid-modified screen-printed carbon electrode (LCA-SPCE) sensor for the determination of the hazardous organophosphorus pesticide methyl parathion (MP) using square-wave adsorptive stripping voltammetry (SWAdSV). The surface of LCA-SPCE was investigated using time of flight secondary ion mass spectrometry to confirm successful preparation of the LCA surface layer. In order to obtain the highest electrochemical response, the accumulation time and pH of the 0.1 M phosphate buffer solution (PBS) supporting electrolyte were optimized. Then, SWAdSV method validation was performed in 0.1 M PBS at pH 6.00, an accumulation potential at the open circuit potential, and an accumulation time of 120 s. Since an intensive background was observed from the measurement of blank solution on the LCA-SPCE, a background subtraction procedure was employed. Partial method validation of the LCA-SPCE sensor was performed by determining the limit of detection (LOD), the limit of quantification (LOQ), the linear concentration range, accuracy, and precision. The developed method has a very low LOD and LOQ of 2.5 µg/L and 5.0 µg/L, respectively, and a linear concentration range of 5.0–84.3 µg/L (R2 = 0.9948). The average recovery and relative standard deviation were 109.6 % and 7.1 %, respectively (n = 6). This work also demonstrates the advantageous use of the multiple standard addition methodology compared to the calibration curve for analysing MP by means of an LCA-SPCE. Furthermore, electrochemical impedance spectroscopy was performed to show the differences between the bare-SPCE and LCA-SPCE. Finally, the application of the developed and validated LCA-SPCE sensor for the determination of MP was successfully employed for a real water sample (tap water), which showed the high accuracy and precision of the method. In addition, the interference and matrix effects were also studied.

Surface Optimization of Glassy Carbon Electrode with Graphitized and Carboxylated Multi-Walled Carbon Nanotubes@β‐Cyclodextrin Nanocomposite for Electrochemical Determination of Methyl Parathion

Surface Optimization of Glassy Carbon Electrode with Graphitized and Carboxylated Multi-Walled Carbon Nanotubes@β‐Cyclodextrin Nanocomposite for Electrochemical Determination of Methyl Parathion

Rapid determination of methyl parathion in vegetables using electrochemical sensor fabricated from biomass-derived and β-cyclodextrin functionalized porous carbon spheres

Porous carbon spheres (PCS) derived from expired sugarcane juice (SJ) and modified with β-cyclodextrin (β-CD) were used for the fabrication of SJPCS@β-CD/GCE sensor with glassy carbon electrode (GCE) to detect methyl parathion (MP). SJPCS with interconnected porous structure exhibits excellent electrical conductivity, strong adsorption property, and high specific surface area, while β-CD with molecular recognition property achieves the uniform dispersion of SJPCS and promotes the recognition and adsorption of MP molecules. Thanks to the synergistic combination of SJPCS and β-CD, the SJPCS@β-CD/GCE sensor exhibited respectable MP determination performance with low limit of detection of 5.87 nM in the MP concentration range of 0.01–10 µM. For the MP detection in vegetables (onion, cabbage, spinach), the fabricated sensor showed good practicability with adequate relative standard deviation of 1.06% to 4.25% and satisfactory recoveries of 96.5 to 100.5%. A promising strategy for the rapid determination of methyl parathion in food products was developed.

Determination of Organophosphorus Pesticides in Vegetables and Fruit by an Indirect Competitive Enzyme-Linked Immunosorbent Assay (ic-ELISA) and a Lateral-Flow Immunochromatographic (LFIC) Strip Assay

Residues of pesticides in agricultural by-products may cause harm to human health. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a competitive form of lateral-flow immunochromatographic (LFIC) strip were developed for the determination of methyl parathion and triazophos in agricultural by-products. In the optimized system for ic-ELISA, the limits of detection (LODs) for methyl parathion and triazophos were 1.39 and 1.94 ng/mL. The linear ranges for methyl parathion and triazophos were from 7.90 to 200 ng/mL and 4.47 to 170.19 ng/mL. The recoveries from agricultural by-products ranged from 84.16 to 106.96% and the coefficients of variation were from 0.77 to 6.45%. In the optimized LFIC system, good linearity was obtained for methyl parathion and triazophos between 5 and 200 ng/mL. The LODs of the CG-LFIC strip for methyl parathion and triazophos were 2.17 and 4.21 ng/mL. The coefficients of variation of the test strip were from 0.73 to 8.34%. Pears, apples, cucumbers, and lettuces spiked with methyl parathion and triazophos were employed to characterize matrix effects using the LFIC strip. The ic-ELISA and LFIC strip were simple and practical for the rapid determination of organophosphorus pesticides in agricultural by-products. Furthermore, the LFIC strip was suitable for on-site testing and rapid screening.

A highly sensitive acetylcholinesterase electrochemical biosensor based on Au–Tb alloy nanospheres for determining organophosphate pesticides

Accurately detect the residues of organophosphate pesticides (OPs) in food and environment is critical to our daily lives. In this study, we developed a novel acetylcholinesterase (AChE) biosensor based on Au–Tb alloy nanospheres (NSs) for rapid and sensitive detection of OPs for the first time. Au–Tb alloy NSs that with good conductivity and biocompatibility were produced with a mild hydrothermal. Under optimal conditions, the AChE biosensor was obtained by a simple assembly process, with a big linear range (10−13–10−7 M) and the limit of detection was 2.51 × 10−14 M for the determination of methyl parathion. Moreover, the determination of methyl parathion with the prepared biosensor presented a high sensitivity, outstanding repeatability and superior stability compared with other reported biosensors. Through the determination of tap water and Yanming lake samples, it was proved that the modified biosensor with satisfactory recoveries (96.76%–108.6%), and are realizable in the determination of OPs in real samples.

Hierarchical nitrogen-doped holey graphene as sensitive electrochemical sensor for methyl parathion detection

Nitrogen-doped HG featuring a hierarchical macro- and nanoporous 3-D architecture with high pyrrolic-N content is a promising candidate for the construction of sensitive graphene-based electrochemical sensors for environmental and bioanalytical applications. • N-doped HG featuring a hierarchical macro- and nanoporous 3-D architecture for determination of MP was fabricated. • Pyrrolic-N in N-HG played a key role in enhanced electrocatalysis. • First principle calculations indicated that pyrrolic-N exhibited the strongest MP adsorption. • N-HG with a high pyrrolic-N content exhibited excellent sensing performance. • Ultra-low detection and excellent recovery in case of real samples were achieved. The determination of organophosphorus pesticide (OPS) residues is of great importance in reducing environmental pollution and ensuring food safety. A high-performance nitrogen-doped holey graphene (N-HG) electrochemical sensor for determination of methyl parathion (MP; one of the most commonly used OPS) based on a hierarchical macro- and nanoporous 3-D architecture has been successfully developed. The influence of various N-configurations on electron transfer kinetics and the sensing performance of the N-HG modified electrode was investigated systematically through combined practical and theoretical studies. Three N-bonding configurations were investigated in N-HG, namely, pyridinic N, pyrrolic N, and graphitic N. It was found that N-HG with a high pyrrolic-N content exhibited the largest electron transfer rate and the best sensing performance (ultralow detection limits: 3.5 pg·ml −1 ; wide linear range: 1 ng ml −1 –150 μg·ml −1 ), indicating that pyrrolic-N in the N-HG played a critical role in the electrochemical process and in enhanced electrocatalysis, as confirmed by first-principle calculations. Furthermore, the N-HG based sensor exhibited excellent selectivity and freedom from interference, good accuracy and satisfactory recoveries for real samples, confirming N-HG based electrochemical sensors have great scope for applications in environmental analysis and bio-sensing.

Nanostructured β‐tricalcium Phosphate (Ca3(PO4)2 Based Electrochemical Sensor for Detection of Methyl Parathion and Mercury (II) Ions

In this work, we have fabricated a new electrochemical sensor based on β‐tricalcium phosphate (Ca3(PO4)2) nanoparticles (NPs) modified glassy carbon electrode (GCE) for the selective nonenzymatic determination of methyl parathion and mercury (II) ions independently. β‐tricalcium phosphate (β‐TCP) NPs were prepared by chemical precipitation method and structural and morphological properties were investigated by XRD, FTIR, and SEM. The electrochemical behavior of MP and mercury (Hg2+) ions were investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques using β‐TCP/GCE. The modified electrode exhibited excellent electrocatalytic activity towards both the MP and Hg over a wide linear range from 0.15 to 141 μM and 1–381 µM with the lowest detection limits of 88 and 136.4 nM respectively. The sensor has high selectivity towards MP and Hg in the presence of major interfering compounds such as 3-nitrophenol, 4-nitrophenol, 4-aminophenol, catechol, hydroquinone and heavy metals such as lead, cadmium and arsenic. Applicability of the fabricated sensor for detection of MP and Hg (II) ions has been tested in tap water by standard addition method.

Ultrasonic-assisted preparation of halloysite nanotubes/zirconia/carbon black nanocomposite for the highly sensitive determination of methyl parathion

Herein, a cost-effective and scalable ultrasound assisted approach was proposed to prepare the nanocomposite of halloysite nanotubes/zirconia/carbon black (Hal/ZrO2/CB), which was used to fabricate a novel electrochemical sensor for the highly sensitive determination of methyl parathion (MP). In the Hal/ZrO2/CB nanocomposite, Hal with large specific surface area and numerous active sites could enhance the adsorption capacity and accelerate the redox reaction of MP; ZrO2 nanoparticles with high affinity toward the phosphate group could contribute to good recognition performance for MP; CB nanoparticles with good dispersibility formed an interconnected pearl-chain-like conductive network. Benefitting from the synergistic effect of the three components, the Hal/ZrO2/CB/GCE (glassy carbon electrode) sensor showed a remarkably low detection limit of 5.23 nM in a good linear MP detection range of 0.01–10 μM. The Hal/ZrO2/CB/GCE sensor possessed a pretty decent practicality with satisfactory RSD and recovery results for the determination of MP in peach, pear, and apple juices. Therefore, the Hal/ZrO2/CB/GCE sensor has important implication on the quite sensitive detection of MP.

Magnetic Fe3O4@SiO2@β-cyclodextrin for solid phase extraction of methyl parathion and fenthion in lettuce samples.

In this study, magnetic Fe3O4@SiO2@β-cyclodextrin copolymerized microparticles were synthesized and applied for the extraction of methyl parathion and fenthion in lettuce samples followed by HPLC-UV detection. The magnetic β-cyclodextrin copolymerized microparticles were prepared by dispersion polymerization with acryloyl β-cyclodextrin as the functional monomer and ethylene glycol dimethyacrylate as the crosslinker. The composite magnetic microparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, magnetic measurement, and thermogravimetric analysis, and used as the adsorbent of magnetic solid-phase extraction (MSPE) for methyl parathion and fenthion. The extraction conditions including sample pH and ionic strength, desorption solvent type and volume, and adsorption and desorption times were optimized. Under the optimal extraction conditions, an MSPE-HPLC-UV method was developed for the detection of methyl parathion and fenthion in lettuce. Wide linear ranges of 1.0-200 μg kg-1 (R2 = 0.9998) for methyl parathion and 1.5-200 μg kg-1 (R2 = 0.9978) for fenthion were obtained and the limits of detection were 0.3 μg kg-1 for methyl parathion and 0.5 μg kg-1 for fenthion in lettuce, respectively. The proposed method was applied for the determination of methyl parathion and fenthion in lettuce with satisfactory recoveries between 89.2-101.2%, and relative standard deviations were less than 9.1%. Thus, the MSPE-HPLC-UV method has high accuracy and sensitivity for the analysis of methyl parathion and fenthion in lettuce samples.

Sensitive, simple and fast voltammetric determination of pesticides in juice samples by novel BODIPY-phthalocyanine-SWCNT hybrid platform

The present work describes the first synthesis of novel asymmetric zinc (II) phthalocyanine (ZnPc) including three boron dipyrromethene (BODIPY) and one ethyloxy azido moieties. Moreover, single walled carbon nanotube (SWCNT) surface was functionalized by this ZnPc containing BODIPY; using the azide-alkyne Huisgen cycloaddition (Click) reaction to obtain SWCNT-ZnPc hybrid material. Structural, thermal and morphological characterizations of both ZnPc and SWCNT-ZnPc hybrid were carried out in-depth by spectroscopic, thermal and microscopic techniques. In this study, the synthesized SWCNT-ZnPc material was decorated on composite glassy carbon electrode (GCE) by means of an easy and a practical drop cast method. The modified electrode was tested as a non-enzymatic electrochemical sensor in various common pesticides such as methyl parathion, deltamethrin, chlorpyrifos and spinosad. Electrochemical behavior of non-enzymatic electrode (GCE/SWCNT-ZnPc) was determined via cyclic voltammetry and differential pulse voltammetry. The non-enzymatic sensor demonstrated high selectivity for methyl parathion in a wide linear range (2.45 nM–4.0 × 10−8 M), low limit of detection value (1.49 nM) and high sensitivity (0.1847 μA nM−1). Also, the developing non-enzymatic sensor exhibited good repeatability (RSD = 2.3% for 10 electrodes) and stability (85.30% for 30 days). Validation guidelines by HPLC and statistical analysis showed that the proposed voltammetric method were precise, accurate, sensitive, and can be used for the routine quality control of methyl parathion determination in juice samples.

Nanocomposite of halloysite nanotubes/multi-walled carbon nanotubes for methyl parathion electrochemical sensor application

We report a simple and highly efficient preparation of nanocomposite of halloysite (Hal) nanotubes/multi-walled carbon nanotubes (Hal-MWCNTs) and its electrochemical sensor application for the determination of methyl parathion (MP). The phase structure and surface morphology of the Hal-MWCNTs nanocomposite were confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectra. According to the electrochemical tests, the fabricated glassy carbon electrode (GCE) sensor with Hal and multi-walled carbon nanotubes showed excellent MP determination performance because of the synergistic effect of Hal and multi-walled carbon nanotubes. The Hal-MWCNTs/GCE sensor exhibited a relatively low detection limit of 0.034 μM in the linear range of 0.5–11 μM. When used for the determination of MP in real samples, the Hal-MWCNTs/GCE sensor showed good detection effect with satisfactory relative standard deviation (RSD) of 2.46 to 3.08% and recoveries of 98.8 of 101.8%. This work indicated that the nanocomposite of Hal-MWCNTs when coated on GCE is useful for the fabrication of high-performance MP electrochemical sensor.

Stripping Voltammetric Determination of Methyl Parathion at Activated Carbon Nanopowder Modified Electrode

AbstractAn activated carbon nanopowder modified glassy carbon electrode (AC‐GCE) was constructed for the sensitive determination of methyl parathion by adsorptive differential pulse anodic stripping voltammetry. The simple and rapid modification procedure included only drop‐coating the electrode surface with a laponite stabilized activated carbon nanopowder suspension and drying. The modifier high adsorption ability, combined with its large electroactive surface area allowed a 30‐fold signal increase to be achieved, compared to bare GCE. Under optimized experimental conditions (activated carbon to laponite ratio, pH and accumulation time), the AC‐GCE exhibited a linear response to methyl parathion in two concentration ranges: from 0.01 μmol L−1 to 1 μmol L−1 and from 1 μmol L−1 to 6 μmol L−1. The LOD of 2.5 nmol L−1 (S/N=3) achieved fitted with regulatory norms. It was demonstrated that the as‐prepared AC‐GCE is suitable for routine real samples analysis.