Detection Of Malathion Research Articles

Determination of Malathion Using Corona Discharge – Ion Mobility Spectrometry with Solid-Phase Microextraction

ABSTRACTA corona discharge (CD) ion mobility spectrometer combined with solid-phase microextraction was constructed. The detection limit and stability of the system for malathion detection were improved using a novel sample introduction port through which the sample desorption was performed in high-temperature drift tube and the sample was introduced directly to the ionization area. The working parameters of the distance between CD needle tip and carrier gas outlet, the drift tube and carrier gas temperature, the carrier gas flow, and the voltage on CD needle were selected. When the extraction time for standard malathion was set to 5 min, the detection limit was 0.96 µg L−1 based on thrice the baseline noise, the linear range was 50–500 µg L−1, the correlation coefficient was approximately 0.9941, and the relative standard deviation was below 10%. Malathion-spiked lake water samples were analyzed using the developed system and the recovery was 92–102%. This method is suitable for the rapid detection of organophosphorus pesticide residues.

Novel electrochemical biosensor based on core-shell nanostructured composite of hollow carbon spheres and polyaniline for sensitively detecting malathion

Abstract A novel electrochemical biosensor was constructed by anchoring acetylcholine esterase (AChE) onto the core-shell nanostructured composite of hollow carbon spheres coated with needle-like polyaniline (denoted by HCS@PANI), and used for rapid determination of malathion, which was established based on the chemisorption/desorption process of AChE used as an indicator. The uniformly distributed HCS was wrapped with the needle-like PANI nanowires to form the HCS@PANI nanocomposite, which not only exhibits high specific surface area and chemical functionality but also possesses strong electrochemical activity. After AChE was adsorbed onto the HCS@PANI nanocomposite, the electrochemical catalysis of AChE/HCS@PANI-based biosensor towards acetylthiocholine chloride (ATCl) was inhibited in the presence of malathion, which was applied to detect malathion, and the biosensor exhibited a low detection limit of 0.16 ng mL−1 within a linear range from 1.0 ng mL−1 to 10 μg mL−1 of the malathion concentration. Also, the results suggested that the developed electrochemical biosensor showed high selectivity, good reproducibility, and applicability for malathion detection, indicating that the proposed method using the HCS@PANI nanocomposite as the sensitive layer for the AChE immobilization and catalysis of ATCl has potential application in high-sensitive pesticide determinations.

Coupling laser desorption with corona beam ionization for ambient mass spectrometric analysis of solution and powder samples

An infrared (940nm) laser desorption coupled with corona beam ionization (LD-CBI) technique was developed for expanding the application of the ambient mass spectrometry (AMS). A black ceramic sample plate was employed to facilitate the non-resonance absorption of laser energy. Solution and powder samples were immobilized in the shallow depression on ceramic plate and desorbed precisely since there was not gas disturbing. The dimer ion (m/z 1216.51) of reserpine was detected without any matrix assistance. In comparison with similar APCI-related ambient technique, the upper mass rang of analyte was broadened significantly. The feasibility of LD-CBI approach was demonstrated with 10 model pesticides. Typically, the limit of detection (LOD) of Malathion was as low as 6pg in the selected reaction monitoring (SRM) mode. The value is 166 times lower than the results from preceding technique desorption corona beam ionization (DCBI). As an APCI related ambient desorption ionization approach, LD-CBI technique could be a well complementary tool for direct detection of solution and powder samples.

Acetylcholinesterase/chitosan-transition metal carbides nanocomposites-based biosensor for the organophosphate pesticides detection

A novel acetylcholinesterase (AChE) biosensor based on transition metal carbides (MXenes) nanosheets and chitosan (CS) had been fabricated successfully for detecting organophosphorous pesticides (OPs). The electrochemical behaviors of the AChE/CS-Ti3C2Tx/GCE biosensor were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The parameters affecting the AChE biosensor performance including pH, enzyme loading, concentration of Ti3C2Tx, and inhibition time were optimized. Under optimum conditions, the AChE/CS-Ti3C2Tx/GCE biosensor exhibited good performance for the detection of malathion with a linearity in range of 1×10−14–1×10−8M and the detection limit was found to be 0.3×10−14M. Due to the excellent biocompatible, no-toxicity, film forming ability of chitosan and the high electrical conductivity and large surface area of the Ti3C2Tx nanosheets, the developed biosensor showed acceptable reproducibility, satisfactory stability, and anti-interference ability. Moreover, the analytical performance of the developed biosensor was demonstrated detecting OPs in practical samples with a satisfactory recovery.

Entomotoxicological study on the forensic blow flies Chrysomya albiceps associated with dog carcass

This study was carried out to identify malathion which may cause the death. Toxicological analysis was applied to the forensically – important blow fly larvae C. albiceps which is the most abundant fly attracted firstly and consume the flesh of carcass as their food substrate. In addition to detection of malathion in tissues of blow fly larvae fed on treated – dog carcasses using gas chromatography with flam ionization detector (GCFID.), the effect of this chemical compound on insect succession, frequency of insects attracted to dog carcass and the development rate of C. albiceps larvae as the most important consumer of carcass tissues and can affect the estimate of postmortem interval (PMI) were investigated.

An Amperometric Acetylcholinesterase Sensor Based on the Bio-templated Synthesis of Hierarchical Mesoporous Bioactive Glass Microspheres

This work describes the synthesis of three-dimensional hollow hierarchical mesoporous bioactive glass (HMBG) microspheres based on Herba leonuri pollen grains via a hydrothermal method. The HMBG microspheres perfectly copied the hierarchical porous structure and inner hollow structure constituting the double-layer surface of the natural Herba leonuri pollen grains. This structural mimicry of the pollen grains resulted in a higher degree of adsorption of acetylcholinesterase (AChE) on HMBG microspheres in comparison with mesoporous bioactive glass. Subsequently, an amperometric biosensor for the detection of Malathion was fabricated by immobilizing AChE onto an HMBG microspheres-modified carbon paste electrode. The biosensor response exhibited two good linear ranges during an incubation time of 10 min in the malathion concentration ranges of 0.02–50 ppb and 50–600 ppb, with a detection limit of 0.0135 ppb (S/N = 3). Overall, the prepared enzymatic biosensor showed high sensitivity in the rapid detection of Malathion and could be applied to detect pesticide residues in vegetable matter. An amperometric acetylcholinesterase (AChE) sensor was successfully prepared using HMBG microspheres as the carrier for adsorption of enzyme. The HMBG microspheres perfectly copied the hierarchical porous structure and inner hollow structure with a double-layer surface of the natural Herba leonuri pollen grains. The hybrid structures resulted in more AChE adsorption and protected the catalytic activity of AChE effectively, which made the sensor sensitive and stable.

Enzyme free Thiol capped CdS Quantum dots based sensing method for the detection of Malathion

This study was focused to develop a cost effective and simple sensing method for Malathion using Thioglycolic acid (TGA) capped Cadmium Sulfide (CdS) quantum dots. Quantum dots (QDs) were synthesized by reflux condensation method and capped with TGA. QDs were characterized by UV-Vis spectroscopy, Spectrofluorometer, FT-IR and HR-TEM. Size of the TGA capped QDs were found to be 2.5 nm. Interaction of Malathion and quantum dots was analyzed by Spectrofluorometer based on photoluminescence (PL) quenching. The lowest detection limit of Malathion was found to be 2 ppb which was observed from the minimum interference it could cause in the PL spectrum.

Colorimetric sensing of malathion using palladium-gold bimetallic nanozyme

In this work, a simple, sensitive and selective label free colorimetric assay using palladium-gold nanorod as nanozyme is reported for malathion detection. Study investigates the peroxidase potential of the nanozyme on colorimetric substrates and explores the effect of selected organophosphates on their enzyme mimetic activity. Palladium-gold nanozyme shows excellent peroxidase mimetic activity with O-phenylenediamine in the presence of hydrogen peroxide. Its Kinetic parameters Km and kcat are better than horseradish peroxidase which makes it a superior enzyme. Nanozyme is stable over a broad temperature range (4–70°C) and shows high peroxidase activity from 2 to 6pH. The peroxidase activity of nanozyme is selectively quenched with increasing concentration of malathion and is the principle of developed assay. Assay has a lowest detection limit of 60ng/ml and shows no cross-reaction with other analogous organophosphates or metal salts. Validation on tap water samples spiked with different concentrations of malathion shows good recovery in the range of 80–106%. Assay also displays good intra and inter-assay precision which lie in the range of 2.7–6.1% and 3.2–5.9% respectively. This study demonstrated the catalytic potential of palladium-gold nanorods, which can be employed as nanozyme for developing highly sensitive detection methods.

Detection of organophosphorus pesticide – Malathion in environmental samples using peptide and aptamer based nanoprobes

The contamination of environment with pesticides residues has necessitated the development of rapid, easy and highly sensitive approaches for the detection of pesticides. Thus, the prime objective of the present strategy was sensing of malathion, a toxic organophosphorus pesticide, widely used in agricultural fields, employing aptamer, cationic peptide and unmodified gold nanoparticles. The role of peptide was carefully evaluated to exploit its potential in colorimetric detection of pesticides. The peptide, when linked to the aptamer renders the gold nanoparticles free and therefore, red in color. However, when the aptamer is associated with malathion, the peptide remains available to cause the aggregation of the nanoparticles and turn the suspension blue. The methodology utilizes the optical changes of the gold nanoparticles for the colorimetric detection of malathion. The method was found to be linear in the range of 0.01–0.75nM with a limit of detection as 1.94pM which is significantly lower than the other available reports. Moreover, the sensitivity of the developed nanoparticle based peptide aptasensor was tested in real samples and the results implied the high practicability of the method. Therefore, the present approach may pave a way for the sensitive, yet simple detection of different analytes without the need of expensive instrumentation.

Chitosan-iron oxide nanocomposite based electrochemical aptasensor for determination of malathion

An electrochemical aptasensor based on chitosan-iron oxide nanocomposite (CHIT-IO) film deposited on fluorine tin Oxide (FTO) was developed for the detection of malathion. Iron oxide nanoparticles were prepared by co-precipitation method and characterized by Transmission electron microscopy and UV–Visible spectroscopy. The biotinylated DNA aptamer sequence specific to the malathion was immobilized onto the iron oxide doped-chitosan/FTO electrode by using streptavidin as linking molecule. Various characterization studies like Field Emission-Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Electrochemical studies were performed to attest the successful fabrication of bioelectrodes. Experimental parameters like aptamer concentration, response time, stability of electrode and reusability studies were optimized. Aptamer immobilized chitosan-iron oxide nanocomposite (APT/SA/CHIT-IO/FTO) bioelectrodes exhibited LOD of about 0.001 ng/mL within 15 min and spike-in studies revealed about 80–92% recovery of malathion from the lettuce leaves and soil sample.

Ultrasensitive aptamer biosensor for malathion detection based on cationic polymer and gold nanoparticles

In this work, we have demonstrated a novel sensing strategy for an organophosphorus pesticide namely, malathion, employing unmodified gold nanoparticles, aptamer and a positively charged, water-soluble polyelectrolyte Polydiallyldimethylammonium chloride (PDDA). The PDDA when associated with the aptamer prevents the aggregation of the gold-nanoparticles while no such inhibition is observed when the aptamer specific pesticide is added to the solution, thereby changing the color of the solution from red to blue. This type of biosensor is quite simple and straightforward and can be completed in a few minutes without the need of any expensive equipment or trained personnel. The proposed method was linear in the concentration range of 0.5–1000pM with 0.06pM as the limit of detection. Moreover, the proposed assay selectively recognized malathion in the presence of other interfering substances and thus, can be applied to real samples for the rapid screening of malathion.

Effective improvement in performance of a miniature FIA-calorimetric biosensing system via denoising column addition and flow rate optimization

The noise reduction and heat-response improvement of a miniature FIA-calorimetric biosensing system were evaluated for the determination of enzyme activity. An innovative denoising column was designed in combination with the use of a mathematical moving average for effectively decreasing signal noise from 30mV to 0.2mV. Additionally, various flow rates were tested for a comprehensive analysis of the influence of the flow rate on the heat response of this system. As the flow rate rose in the 0.1–0.5mL/min range, the temperature sensitivity of the calorimetric system increased linearly from 0.8mV/K to 1.184mV/K, showing an improvement of 48%. However, the exothermic peak integral reached the highest point at the flow rate of 0.3mL/min, when the system was used to detect the heat release of hydrolysis reaction catalysed by chicken liver esterase. Thus, the flow rate of 0.4mL/min was finally employed in this system. The biosensor was successfully applied for the detection of malathion, where 0.01mg/L malathion was detected significantly. Thus, this biosensor could potentially be used for the determinations of inhibitors based on enzyme inhibition methods.

A Paper‐based Mitochondrial Electrochemical Biosensor for Pesticide Detection

AbstractIn this article, we detail a paper‐based three‐electrode electrochemical biosensor using a mitochondria modified Toray carbon paper working electrode. Cyclic voltammetry performed on the paper‐based biosensor and similar electrodes in a common laboratory setup (not in an integrated paper‐based device) compare favorably. In addition, instant detection of malathion with a detection limit of 20 nM by cyclic voltammetry is demonstrated, showing the device can potentially be used as a portable platform for pesticides detection.

Acetylcholinesterase inhibition-based ultrasensitive fluorometric detection of malathion using unmodified silver nanoparticles

Abstract An ultrasensitive sensor was developed for the detection of an organophosphorus compound using unmodified silver nanoparticles (AgNPs). The hydrolysis of acetylthiocholine (ATCh) by acetylcholinesterase (AChE) generates a thiol-containing compound, thiocholine, which influences the AgNP aggregation. Herein, we describe an indirect enzyme-based detection of malathion with AChE and ATCh in the presence of AgNPs using the fluorometric method. The addition of malathion to the system decreased the enzyme hydrolysis and thiocholine generation, and thus was able to quench the AgNPs, with a corresponding decrease in the emission intensity at 423 nm ( λ ex = 340 nm). The proposed system showed linearity in the range, 2–100 fM, with an excellent limit of detection of 0.556 fM by fluorescence spectroscopy. The aggregation and disaggregation of AgNPs were also supported by transmission electron microscopy and dynamic light scattering analyses. The potential application of the system was demonstrated by determination of malathion in real samples like agricultural runoff water, lake water, cabbage, and apple samples using fluorometric method, and the obtained results were further validated with HPLC.

Assessment of malathion and its effects on leukocytes in human blood samples

In the present paper, we report a reproducible, cost effective, fast response method for detection of malathion and its effects on leukocytes in different human blood groups. Spectroscopic methods (UV-Vis spectrometry) and Fourier transform infrared coupled with solid phase extraction were applied for analyzing malathion content in human blood plasma. The spiking levels of malathion in the range of 0.1-1.7 µg/mL were extracted from blood plasma samples using SPE. The present active functional groups (C = O; P-O-C; -OH; P = S) were also characterized. The recovery rate of malathion was 80%±4.5%. The calculated correlation coefficient was 0.9799, indicating the linearity of the results. The limit of detection (LOD) and limit of quantification (LOQ) were (0.1-1.7) µg/mL and (0.3-1.5) µg/mL, respectively. Malathion <1.0 µg/mL showed no significant change while higher levels of malathion exposure (1.5 µg/mL and 3.0 µg/mL) reduced the number of white blood cells. In conclusion, the spectroscopic results may be useful to understand the mechanism of other pesticides such as methyl parathion and parathion.

Detection of malathion in food peels by surface-enhanced Raman imaging spectroscopy and multivariate curve resolution

An analytical methodology was developed for detection of malathion in the peels of tomatoes and Damson plums by surface-enhanced Raman imaging spectroscopy and multivariate curve resolution. To recover the pure spectra and the distribution mapping of the analyzed surfaces, non-negative matrix factorization (NMF), multivariate curve calibration methods with alternating least squares (MCR-ALS) and MCR with weighted alternating least square (MCR-WALS) were utilized. Error covariance matrices were estimated to evaluate the structure of the error over all the data. For the tomato data, NMF-ALS and MCR-ALS presented excellent spectral recovery even in the absence of initial knowledge of the pesticide spectrum. For the Damson plum data, owing to heteroscedastic noise, MCR-WALS produced better results. This methodology enabled detection below to the maximum residue limit permitted for this pesticide. This approach can be implemented for in situ monitoring because it is fast and does not require extensive manipulation of samples, making its use feasible for other fruits and pesticides as well.

New probe for fluorescence detection of Azinphous ethyl, Malathion and Heptachlor pesticides

Luminescence quenching of long lived Eu(III)–Bathophenanthroline (Batho) probe of 1:2 stoichiometric ratio has been studied in acetonitrile in the presence of the pesticides Azinphous ethyl (P1), Malathion (P2) and Heptachlor (P3). The luminescence intensity of Eu(III)–(Batho)2 probe decreases as the concentration of the pesticide increases. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)–(Batho)2 probe in solution. The detection limits were 0.68, 0.92 and 0.35µM for P1, P2 and P3, respectively. Stern–Volmer studies at different temperatures indicate that collisional quenching dominates for Azinphous ethyl, Malathion and Heptachlor. The binding constants (K) and thermodynamic parameters (ΔS°, ∆H° and ∆G°) of the interaction of pesticides with the complex were evaluated.

In vitro selection of a single-stranded DNA molecular recognition element for the pesticide malathion.

Many large-scale applications of the organophosphate pesticide malathion have led to widespread environmental contamination. Concentrations are found in the environment well above those which are harmful to humans and environmental organisms. No current method of detection for this pesticide is rapid, cost-effective, and specific for malathion. Therefore, we utilized a stringent Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process to identify a Molecular Recognition Element (MRE) for malathion. This MRE was identified from a large ssDNA library and has an equilibrium dissociation constant (Kd) in the low-nanomolar range. Additionally, it has significant selectivity for malathion in comparison to various other pesticides and metabolites of malathion, which were used as negative targets of selection. The high affinity and selectivity of the ssDNA MRE for malathion is a product of the stringent SELEX selection scheme and will be useful for rapid, inexpensive, and specific detection of malathion in the environment.

Study of the Effect of Air to Fuel Ratio Parameter on the Organophosphorus – Pesticide Analysis by GC-FPD

In the present contribution, sensitive and precise method for the quantification of Organophosphorus / Pesticides (Malathion and Dimethoate) in nanograms range has been developed. The performance of flame photometric detector (FPD), a selective detector (P&amp;S-mode) that can be used in the analysis of organophosphorus compound, is evaluated in terms of sensitivity, selectivity and reproducibility. The performance of flame photometric detector was strongly depending on the absolute and relative flow rate of air and hydrogen gases. The optimum air-to-fuel ratio for detection of Malathion and Dimethoate was 0.4 and 0.3 (FPD-P mode). At this ratio, low picogram amounts of phosphor can be detected accurately (0.18 pgP) with a wide linear dynamic range of 0.18 pgP to 298 ngP. While, the optimum air-to-fuel ratio, for detection of Malathion and Dimethoate was 0.6 (FPD-S mode). In addition to, the method is precise with 4.5 % relative standard deviation (RSD). In conclusion, it could be proposed that this procedure can be recommended as a suitable method for the quantification of Malathion and Dimethoate in cases of acute poisoning.

Study of the Effect of Air to Fuel Ratio Parameter on the Organophosphorus – Pesticide Analysis by GC-FPD

In the present contribution, sensitive and precise method for the quantification of Organophosphorus / Pesticides (Malathion and Dimethoate) in nanograms range has been developed. The performance of flame photometric detector (FPD), a selective detector (P&amp;S-mode) that can be used in the analysis of organophosphorus compound, is evaluated in terms of sensitivity, selectivity and reproducibility. The performance of flame photometric detector was strongly depending on the absolute and relative flow rate of air and hydrogen gases. The optimum air-to-fuel ratio for detection of Malathion and Dimethoate was 0.4 and 0.3 (FPD-P mode). At this ratio, low picogram amounts of phosphor can be detected accurately (0.18 pgP) with a wide linear dynamic range of 0.18 pgP to 298 ngP. While, the optimum air-to-fuel ratio, for detection of Malathion and Dimethoate was 0.6 (FPD-S mode). In addition to, the method is precise with 4.5 % relative standard deviation (RSD). In conclusion, it could be proposed that this procedure can be recommended as a suitable method for the quantification of Malathion and Dimethoate in cases of acute poisoning.