一种高亲核怀长链咪唑肟的合成与反应

报道了一种新的高亲核长链咪唑肟N-十四烷基咪唑-2-甲醛肟的设计与合成， 并比较了它及其他长链咪唑肟与有机磷酸酯二苯基、对硝基苯基磷酸酯（PNPDPP） 、对硫磷及V_x的反应活性。结果表明，该肟对PNPDPP、对硫磷等磷酸酯反应活性 很高，超过目前已报道的反应活性最强的肟基试剂5～10倍，可用于毒性高且难以 分解的磷酸酯消毒与防护。     

Degradation study of selected organophosphorus insecticides in natural waters

The degradation of 15 organophosphorus insecticides was studied in drinking, ground, and surface waters under different laboratory-controlled and environmental conditions. Surface waters originated from rivers Savinja (near the city of Celje) and Kamniska Bistrica (at the spring), which both belong to the Danube river basin. Groundwater was collected from wells (70?m deep) in Ljubljana, which are the direct source of drinking water for the capital. These matrices were selected on the basis of their different chemical composition and microbial activity. Major factors influencing the degradation were determined, such as temperature, oxygen, sunlight, pH, and type of water. The degradation of atrazine, present in many water sources in Slovenija, was followed simultaneously as a reference under the same conditions. The degradation kinetics was followed by gas chromatography with mass-selective detection, which also allowed the identification of some degradation by-products, such as oxon analogues paraoxon, dyfoxon, malaoxon, phenyl-methyl sulfoxide, fenthion sulfone, phorate sulfoxide, and phorate sulfone. The results show that the half-lives of the selected organophosphorus insecticides varied from 4 to 192 days or more, depending on the water source and experimental conditions. As a result, kinetically constants and half-lives were calculated for every tested insecticide, and major degradation products were determined.     

A novel amperometric sensor and chromatographic detector for determination of parathion

A novel amperometric sensor and chromatographic detector for determination of parathion has been fabricated from a multi-wall carbon nano-tube (MWCNT)/Nafion film-modified glassy-carbon electrode (GCE). The electrochemical response to parathion at the MWCNT/Nafion film electrode was investigated by cyclic voltammetry and linear sweep voltammetry. The redox current of parathion at the MWCNT/Nafion film electrode was significantly higher than that at the bare GCE, the MWCNT-modified GCE, and the Nafion-modified GCE. The results indicated that the MWCNT/Nafion film had an efficient electrocatalytic effect on the electrochemical response to parathion. The peak current was proportional to the concentration of parathion in the range 5.0×10^–9–2.0×10^–5 mol L^–1. The detection limit was 1.0×10^–9 mol L^–1 (after 120 s accumulation). In high-performance liquid chromatography with electrochemical detection (HPLC–ED) a stable and sensitive current response was obtained for parathion at the MWCNT/Nafion film electrode. The linear range for parathion was over four orders of magnitude and the detection limit was 6.0×10^–9 mol L^–1. Application of the method for determination of parathion in rice was satisfactory.     

Characterization of Multihapten Antigens on Antibody Sensitivity and Specificity for Parathion

Four multihapten antigens were conjugated to a single protein to obtain broad-specific polyclonal antibody characterization. The sensitivity and specificity of the polyclonal antibodies for parathion were evaluated with differences due to the structure of the determinant or the number of multihapten antigens. The sensitivity of immunoassay may decrease with a corresponding increase in the number of antigens in a multihapten immunogen or with an increase in complexity of the structure. The specificity of other analytes may broaden when the determinants of multihapten have similar structures.     

Determination of parathion in biological fluids by means of direct solid-phase microextraction

A new and simple procedure for the determination of parathion in human whole blood and urine using direct immersion (DI) solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) is presented. This technique was developed using only 100 μL of sample, and ethion was used as internal standard (IS). A 65-μm Carbowax/divinylbenzene (CW/DVB) SPME fibre was selected for sampling, and the main parameters affecting the SPME process such as extraction temperature, adsorption and desorption time, salt addition, agitation and pH effect were optimized to enhance the sensitivity of the method. This optimization was also performed to allow the qualitative determination of parathion’s main metabolite, paraoxon, in blood. The limits of detection and quantitation for parathion were 3 and 10 ng/mL for urine and 25 and 50 ng/mL for blood, respectively. For paraoxon, the limit of detection was 50 ng/mL in blood. The method showed linearity between the LOQ and 50 μg/mL for both matrices, with correlation coefficients ranging from 0.9954 to 0.9999. Precision and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The mean absolute recoveries were 35.1% for urine and 6.7% for blood. Other parameters such as dilution of sample and stability were also validated. Its simplicity and the fact that only 100 μL of sample is required to accomplish the analysis make this method useful in forensic toxicology laboratories to determine this compound in intoxications, and it can be considered an alternative to other methods normally used for the determination of this compound in biological media.     

Preparation and Electrochemical Characters of Parathion Molecule Imprinted Polymeric Sensors

A sensitive, fast and low-cost molecular imprinted polymeric sensor for quantitative determination of parathion was prepared with chitosan(CS) as function matrix and parathion(PT) as template molecule via constant potential electrochemical deposition. Sensitive response was obtained with a detection limit of 1.0×10–7 mol/L and an excellent recognition for PT was achieved due to the good memory capacity of the sensor. The developed sensor exhibited good fabrication reproducibility and acceptable stability, w...     

Hapten design and indirect competitive immunoassay for parathion determination: correlation with molecular modeling and principal component analysis

A novel procedure for parathion hapten design is described. The optimal antigen for parathion was selected after molecular modeling studies of six types of potentially immunizing haptens with the aim to identify the best mimicking target analyte. Heterologous competitive indirect enzyme-linked immunosorbent assay (ELISA) was developed after screening a battery of competitors as coating antigens. The relationship between the heterology degree of the competitor and the resulting immunoassay detectability was investigated according to the electronic similarities of the competitor haptens and the target analyte. Molecular modeling and principal component analysis were performed to understand the electronic distribution and steric parameters of the haptens at their minimum energetic levels. The results suggested that the competitors should have a high heterology to produce assays with good detectability values. An indirect competitive ELISA was finally selected for further investigation. The immunoassay had an IC₅₀ value of 4.79 ng mL⁻¹ and a limit of detection of 0.31 ng mL⁻¹. There was little or no cross-reactivity to similar compounds tested except for the insecticide parathion-methyl, which showed a cross-reactivity of 7.8%.     

Degradation of Methyl Parathion,a common pesticide and fluorescence quenching of Rhodamine B,a carcinogen using β-d glucan stabilized gold nanoparticles

Natural carbohydrate polymer β-d-glucan extracted from Tricholoma crassum (Berk.) Sacc. predominantly linked by β-glycosidic bonds have been used to synthesize gold nanoparticles (Au NPs). As glucan is water soluble, the Au NPs are prepared in water medium, a green solvent. The morphology and characterization of the synthesized Au NPs have been confirmed by various techniques, like TEM, EDX, XRD, UV–Vis and FT-IR spectroscopic studies. The obtained Au NPs exhibits chemosensing property against Methyl Parathion, a group of highly toxic organophosphorous pesticide, extensively used as an agricultural chemical. Degradation of parathion using Au NPs lead to water-soluble products thereby reducing the toxicity of Methyl Parathion by disrupting the thiophosphate-ester linkage. The synthesized Au NPs also act as a good fluorescence quencher of Rhodamine B, a common fluorophore and carcinogenic compound, obeying Stern-Volmer equations. The β-d-glucan capped Au NPs are safe having possible medicinal usage.     

对硫磷分子印迹聚合物制备及其在水质检测中的应用

为了有效的分离富集水样中有机磷农药,以对硫磷为模板、三羟甲基丙烷三丙烯酸酯为交联剂,采用紫外聚合方法制备了对硫磷分子印迹聚合物(MIP)。利用紫外光谱、红外光谱研究了对硫磷与不同功能单体间作用力及印迹聚合物的结合位点。利用该MIP,建立MIP-固相萃取-气相色谱法测定水中痕量对硫磷,方法的检出限(3S/N)为0.48μg/L,加标回收率为86.2%～115.7%,相对标准偏差(n=6)为3.0%～6.6%。