Kinds Of Organophosphorus Pesticides Research Articles

Development of a noncompetitive magnetic-phage anti-immunocomplex assay for detecting of organophosphorus pesticides with a thiophosphate group

Organophosphorus pesticides (OPs) are widely used in agriculture and the monitoring of their residues is very important to protect human health. Immunoassays are important tools for the analysis of small molecules. Generally, noncompetitive mode of immunoassay is considered to be more sensitive than competitive mode. In this study, peptides that can identify immunocomplex of OPs were screened from a phage display library. Subsequently, a second-generation peptide library was constructed and peptides with better performance were isolated. Then, a rapid and sensitive noncompetitive magnetic-phage anti-immunocomplex assay (MPHAIA) for OPs was developed based on the best phage-peptide and single chain antibody immunomagnetic beads. The MPHAIA showed broad specificity for OPs with a thiophosphate group. The half-saturated concentration (SC50) values and limits of detection (LODs) of MPHAIA to 12 OPs were ranged from 15.04 to 105.48 ng/mL and 4.07–14.19 ng/mL, respectively. The accuracy and reliability of MPHAIA were verified by gas chromatography-tandem mass spectrometry (GC-MS/MS) parallel analysis of six kinds of OPs in spiked cucumber samples. The recovery rates were in range of 81.2–116.3% with coefficient of variation from 4.1% to 14.1%, which were consistent with the results of GC-MS/MS.

Ionic Liquid–Based Dispersive Liquid–Liquid Micro-extraction of Five Organophosphorus Pesticides in Coarse Cereals

A dispersive liquid–liquid micro-extraction method was combined with high-performance liquid chromatography to rapidly and efficiently separate and detect organophosphorus pesticide residues in coarse cereals. In order to select the best conditions, the extraction conditions, including the type and volume of the extraction agent, the type and volume of the dispersant, extraction time, pH, and the amount of NaCl, were optimized. [HMIM][PF6] was selected as the extraction agent and [HMIM][BF4] as the dispersant. Five kinds of organophosphorus pesticides, including trichlorfon, chlorpyrifos, phoxim, fenthion, and diazinon, were extracted and separated by using dispersive liquid–liquid micro-extraction from coarse cereals. The results show that the recoveries are between 85.3 and 107.3%. The simple, rapid, and efficient new method for extracting and separating organophosphorus pesticides of coarse cereals was established and applied.

Colorimetric Detection of Organophosphorus Pesticides Based on the Broad-Spectrum Aptamer.

Organophosphorus pesticides (OPs) are an important class of common pesticides. However, due to the abuse of organophosphorus pesticides, pesticide residue problems have been highlighted. In this study, the colorimetric detection method for OPs residues was established based on the broadspectrum aptamer. Through optimization, isocarbophos and omethoate were analyzed to verify the performance of the colorimetric assay. Under optimal conditions, the method proved effective for detecting an isocarbophos range of 50-1000 ng/mL and an omethoate range of 100-500 ng/mL. The protective effects of broad-spectrum aptamers and the split (28-mer P1+26-mer P2) aptamers on gold nanoparticles (AuNPs) were also comparatively studied. The present results suggested that the colorimetric assay based on broad-spectrum aptamer could be applied for a preliminary screening of different kinds of OPs.

Simultaneous Analysis of Eight Kinds of Organophosphorus Pesticides for Inspection of Residual Pesticides in Import-Export Agricultural Products

Simultaneous Analysis of Eight Kinds of Organophosphorus Pesticides for Inspection of Residual Pesticides in Import-Export Agricultural Products

Double quantum dots-nanoporphyrin fluorescence-visualized paper-based sensors for detecting organophosphorus pesticides

A high-sensitivity fluorescence visualization paper-based sensor is developed and used to achieve specific detection and analysis of three organophosphorus pesticides (OPPs: dimethoate, dichlorvos, and demeton) in a "Turn-off-on" detection mode. The fluorescence visualization paper-based sensor is established through combining double quantum dots (QDs) with high-activity nanoporphyrins (QDs-nanoporphyrin), realizing double nanometer signal amplification and producing different color change responses to these three OPPs. In particular, this approach is based on Partial least squares discriminant analysis (PLSDA) for fingerprint spectrum analysis of three kinds of organophosphorus pesticides in complex matrix (apple and cabbage). Therefore, different concentrations of pesticide residues can be quickly identified at the same time with 100% accuracy for both training set and prediction set. In summary, this method has high selectivity and stability, and thus provides a new approach for the identification of organophosphorus residues in complex systems.

Health Risk Evaluation of Organochlorine and Organophosphorous Pesticides in Groundwater in Beijing

Pollution from organochlorine (OCP) and organophosphorus (OPP) pesticides in groundwater is a key issue for water resource protection. Sixteen kinds of OCP and six kinds of OPP pesticides were detected in 18 groundwater samples determined by GC-MS. Results showed that seven kinds of OPCs and two kinds of OPPs were found in the groundwater in Beijing. Among the OCPs, there were mainly hexachlorobenzene (HCB), hemochromatosis (HCH), and dichlorodiphenyltrichloroethane (DDT), with maximum values of, respectively, 82.4, 193, and 158 ng·L-1. Among the OPPs, there were o, o-dimethyl-o-2,2-dichlorovinylphosphate and o,o-dimethyl methylcarbamoylmethyl phosphorodithioate, with maximum values of 7.1 ng·L-1 and 17.7 ng·L-1, respectively. The OCPs and OPPs were found in the sewage irrigation areas. The results of a probabilistic risk assessment showed that the non-carcinogenic and carcinogenic risks of OCPs and OPPs within the drinking water in Beijing had been controlled, that risks from OCPs were higher, and that women were more sensitive to the toxicity of the pesticides. The monitoring of HCH and DDT in the groundwater should be implemented.

Human health risk assessment of organophosphorus pesticides in maize (Zea mays L.) from Yushu, Northeast China

ABSTRACTIn order to investigate organophosphorus pesticides (OPs) concentrations in maize and estimate the health risk to consumers, a total of 55 samples were collected from Yushu, one of the most important maize production areas. The concentrations of the eleven detected OPs in maize were analyzed by gas chromatography coupled with flame photometric detector (GC-FPD). The results showed that OPs concentrations of all maize were not higher than maximum residue limit (MRL), 67.3% of samples below MRL and only in 32.7% of samples was not found OPs. The mean concentrations obtained for the eleven OPs in μg kg-1 were as follows: omethoate (0.8), quinalphos (0.8), phorate (0.7), dimethoate (0.7), parathion-methyl (0.6), isocarbophos (0.6), diazinon (0.5), fenitrothion (0.5), and malathion (0.5), with parathion (0.5) and fenthion (0.3). Phorate (16.4%), dimethoate (16.4%) and quinalphos (16.4%) had the highest frequency in the eleven OPs. 29.1% samples contained two or more kinds of OPs, while 38.2% samples detected one kind of OPs. The target hazard quotients (THQ) values were all less than one and the total acute hazard index (aHI) values for adults and children were 0.051 and 0.121, respectively indicating that consumer may not pose significant chronic and acute health risk through maize.

Benzyl Functionalized Ionic Liquid as New Extraction Solvent of Dispersive Liquid-liquid Microextraction for Enrichment of Organophosphorus Pesticides and Aromatic Compounds

Abstract A benzyl functionalized ionic liquid, 1-benzyl-3-methylimidazolium bis [(trifluoromethyl) sulfonyl] imide ([BeMIM][Tf 2 N]), was synthesized and used as an extraction solvent of dispersive liquid-liquid microextraction (DLLME) for enrichment and determination of 5 kinds of organophosphorus pesticides (phoxim, fenitrothion, chlorpyrifos, phorate and parathion) and 2 kinds of aromatic compounds (chloronaphthalene and anthracene) in environmental water samples by high-performance liquid chromatography (HPLC). [BeMIM][Tf 2 N] had higher extraction efficiency than 1-octyl-3-methylimidazolium bis [(trifluoromethyl)sulfonyl] imide and common organic solvents such as carbon tetrachloride and tetrachloroethylene. The extraction was performed using 40 μL of [BeMIM][Tf 2 N] as respective extraction solvent and 1 mL of methanol as dispersive solvent with centrifugal time of 5 min. Under the optimal conditions, the proposed method exhibited a good linearity for all analytes with correlation coefficients of 0.9994−0.9998. The precision, described as intra-day and inter-day relative standard deviations (RSDs) of five replicate experiments at three different concentrations of 10, 40 and 100 μg L −1 , was 1.1%–4.3% and 0.8%–4.8%, respectively. The limits of detection (LODs) were 0.01–1.0 µg L −1 ( S/N = 3). The developed method was convenient, rapid and applicable to detection of the analytes in real environmental water samples with satisfactory recovery of 82.7%–118.3% and RSDs of 0.7%–5.6%. Introduction of benzyl group into the imidazolium could considerably elevate the extraction efficiecny of the analytes due to enhanced π-π interaction between [BeMIM][Tf 2 N] and analytes. [BeMIM][Tf 2 N] was a satisfactory extraction solvent with a high enrichment factor of 339 and extraction efficiency of 81.4%. The partition coefficients of all analytes in [BeMIM][Tf 2 N]-DLLME system were determined and the extraction mechanism was discussed.

Novel restricted access materials combined to molecularly imprinted polymers for selective solid-phase extraction of organophosphorus pesticides from honey

A novel restricted access materials (RAM) combined to molecularly imprinted polymers (MIPs), using malathion as template molecule and glycidilmethacrylate (GMA) as pro-hydrophilic co-monomer, were prepared for the first time. RAM-MIPs with hydrophilic external layer were characterized by scanning electron microscopy and recognition and selectivity properties were compared with the restricted access materials-non-molecularly imprinted polymers (RAM-NIPs) and unmodified MIPs. RAM-MIPs were used as the adsorbent enclosed in solid phase extraction column and several important extraction parameters were comprehensively optimized to evaluate the extraction performance. Under the optimum extraction conditions, RAM-MIPs exhibited comparable or even higher selectivity with greater extraction capacity toward six kinds of organophosphorus pesticides (including malathion, ethoprophos, phorate, terbufos, dimethoate, and fenamiphos) compared with the MIPs and commercial solid phase extraction columns. The RAM-MIPs solid phase extraction coupled with gas chromatography was successfully applied to simultaneously determine six kinds of organophosphorus pesticides from honey sample. The new established method showed good linearity in the range of 0.01–1.0μgmL−1, low limits of detection (0.0005–0.0019μgmL−1), acceptable reproducibility (RSD, 2.26–4.81%, n=6), and satisfactory relative recoveries (90.9–97.6%). It was demonstrated that RAM-MIPs solid phase extraction with excellent selectivity and restricted access function was a simple, rapid, selective, and effective sample pretreatment method.

Simultaneous Analysis of Organophosphorus Pesticides in Water by Magnetic Solid-Phase Extraction Coupled with GC–MS

Magnetic solid-phase extraction (MSPE) coupled with gas chromatography–mass spectrometry was applied for the analysis of organophosphorus pesticides (OPPs) in water samples. We chose C18-functionalized Fe3O4@mSiO2 microspheres as the magnetic sorbents to extract and enrich OPPs from water samples with the advantages of good solubility in water, large surface area and fast separation ability. In this study, six kinds of OPPs were analyzed and various parameters of MSPE procedure, including eluting solvent, the amount of magnetic absorbents and extraction time were optimized. Validation experiments showed that the optimized method had good linearity with correlation coefficients r 2 > 0.98 and satisfactory precision with the relative standard deviation ≤10.7 %. The limits of detection were 1.8–5.0 μg L−1 and the limits of quantification ranged from 6.1 to 16.7 μg L−1. We concluded that the proposed method was successfully applied to analyze OPPs in real water samples and the results indicated that it had the advantages of simplicity, convenience and efficiency.

The diagnostic value of butyrylcholinesterase in acute organophosphorus pesticide poisoning

To assess the value of butyrylcholinesterase (BuChE) in the diagnosis of acute organophosphorus pesticide poisoning (AOPP), and to investigate the relationship between the activity of whole blood acetylcholinesterase (AChE) and plasma BuChE in patients of AOPP in order to re-evaluate the diagnostic value of BuChE. An improved Ellman method was employed to determine the activity of AChE and BuChE in 21 AOPP inpatients due to different kinds of pesticides (from April to September in 2009) during the course of the illness, with 26 healthy volunteers as normal control. The relationship between BuChE activity and other clinical indicators of 113 inpatients (from January 2008 to April 2009) was also retrospectively analyzed. The normal value of AChE and BuChE were (105 + or - 33) U/Hb and (15 807 + or - 3 495) U/L . The inhibition levels of these two enzymes were different. When the AChE activity was lower than 50%, 30% or 20%, the activity of BuChE was lower than 20%, 10% or 5% correspondingly. The tendency of changes in the two enzymes was similar and coincided well with the clinical symptoms after poisoning. The results of sequential detection showed that a significant decrease or persistent inhibition of BuChE activity by less than 5% indicated a high level of organophosphorus pesticide in the body. However, an elevation of BuChE indicated a favorable outcome. BuChE is one of the ideal diagnostic and classification criteria for AOPP. When the inhibition level of BuChE reaches 20%, AOPP is of moderate degree, when it reaches 10%, severe AOPP can be diagnosed, with different kinds of organophosphorus pesticides taken into consideration.

Survey of Pesticide Residues in Imported Cereal Products (1994.4∼2006.3)

A survey of pesticide residues in 490 imported cereal products on the Tokyo market from April 1994 to March 2006 was carried out. Eight kinds of organophosphorus pesticides (chlorpyrifos, chlorpyrifos-methyl, DDVP, diazinon, etrimfos, malathion, MEP and pirimiphos-methyl) were detected at levels between Tr (below 0.01 ppm) and 0.82 ppm from 91 samples. In our investigations, chlorpyrifos-methyl and malathion tended to be detected in samples from America, pirimiphos-methyl in those from Europe, and MEP in those from Oceania. Thus, pesticide residues seemed to be different in produce from different areas. Residue levels of these pesticides were calculated as between 0.08 and 13.2% of their ADI values according to the daily intake of cereal products. Therefore, these cereal products should be safe for normal usage.

Follow-up study on psychic and neuropathic delayed effects of acute organophosphorus pesticides poisoning

To study the delayed effect on neuropsychopathy and its related factors after acute organophosphorus pesticides poisoning (AOPP). Two hundred and fifty-seven cases of AOPP in the observation period were chosen to follow-up 2 months later from the 4 county hospitals in Shandong Province where the incidence of organophosphorus pesticide poisoning is high. Nine cases of organophosphate induced delayed polyneuropathy (OPIDP) were found and the incidence rate was 3.5%. The occurrence of OPIDP were related to the need for emergent artificial respiration, and the degree of poisoning, and the kinds of organophosphorus pesticides (Ops). The positive rate of symptoms of peripheral nerves, central nerves and psychogeny except auditory and visual hallucination after poisoning was significantly higher than that before (P < 0.05). The patient's situation of health, economy and work became statistically worse (P < 0.05). We found some had delayed effects on neuropsychopathy after AOPP which could debase the patient's life quality. The control measure should be administered as early as possible.

A simple determination for 8 kinds of organophosphorus pesticides from animal tissues. Application to toxicological experiments.

A simple determination for eight kinds of organophosphorus pesticides (OPs) from animal tissues was newly developed. OP was extracted from the sample with acetonitrile, added 2% NaCl solution, and reextracted with n-hexane. The organic layer was loaded to a Sep-Pak silica cartridge and OP retained in the cartridge was eluted with ethyl acetate. The eluate was dried up under a stream of nitrogen. The residue was dissolved in n-hexane and the OP was determined by use of gas chromatograph (GC) equipped with a flame photometric detector (FPD). When nine OPs were separately added to four tissues (muscle, liver, adipose tissue and blood) of hen at the level of 5μg per 0.5 g of tissue weight, recoveries of fenitrothion, malathion, fenthion, parathion, cyanofenphos, EPN and leptophos ranged from 79.8% to 96.9%. In the case of cyanophos, recoveries from muscle, liver and adipose tissue were from 83.1% to 91.9%, but recovery from blood was 60.1%. Recoveries of dichlorvos from muscle, liver, adipose tissue and blood were below 18.8%. These results demonstrate that this simplified method is applicable to the determination of the above eight OPs except dichlorvos from animal tissues.

Pesticide Residues in Crude Drugs and Pharmaceutical Preparations Containing Crude Drugs

The residual contents of pesticides in 13 commercial crude drugs, their decoctions and 15 commercial pharmaceutical preparations which contain crude drugs were determined by using gas chromatography. Eleven kinds of organochlorine pesticides and 9 kinds of organophosphorus pesticides were examined. From the several crude drugs, 8 kinds of organochlorine pesticides were detected, but no organophosphorus pesticides were found from the crude drugs. The maximum values of BHC isomers (total BHC), DDT and related compounds (total DDT), dieldrin and heptachlor epoxide were 0.452 ppm, 0.089 ppm, 0.010 ppm and 0.039 ppm, respectively. The organochlorine pesticides in decoctions prepared from the crude drugs were found to decrease to 0-9.4% of those in the raw crude drugs. The tablets and pills containing powdered crude drugs were found to include higher amounts of organochlorine pesticides than the tablets containing the extracts of crude drugs. More than 1 ppm of total DDT was determined in the soft capsules with fish-liver oil. More than 1 ppm of total BHC and heptachlor epoxide were determined in the soft extract of Ginseng. The potential daily intakes of these pesticides from all samples were calculated. The values obtained were under 5% of acceptable daily intake (ADI) recommended by WHO.