In order to prevent pesticide leaching from soil, the effects of charcoal amendment on adsorption-desorption of isoproturon in soils were studied and the mechanisms in reducing the loss of isoproturon from soils were ...In order to prevent pesticide leaching from soil, the effects of charcoal amendment on adsorption-desorption of isoproturon in soils were studied and the mechanisms in reducing the loss of isoproturon from soils were suggested. Adsorption-desorption of isoproturon in five different particle sizes of charcoals and three different soils were studied using batch equilibration technique. The results showed that the experimental data were well fitted by the Freundlich empirical equation. Charcoal had a great adsorption capacity for isoproturon, and the smaller the particle size of charcoal, the more the adsorption of isoproturon. The amendment with charcoal could greatly improve the adsorption of isoproturon in soils. The adsorption of isoproturon in soils increased with the rate of charcoal amended （r= 0.9568＊＊, P 〈 0.01）. Desorption of isoproturon from charcoals and soils showed significant hystersis which was shown by the higher adsorption slope （1/nsds） compared to the desorption slope （1/ndes. The hysteresis effects of charcoal on desorption of isoproturon were closely correlated with the content of charcoal in the soils, and the hysteresis index （H） increased with the rate of charcoal amended. Observation of environmental scanning electron microscopy （ESEM） exhibitted the fine pore structure and special surface characteristics of the tested charcoal. Analysis of Fourier transform infrared spectra （FTIR） of isoproturon adsorbed on charcoal suggested probable bonding interactions between isoproturon and charcoal. This research suggests that charcoal amendment may be an effective management practice for controlling pesticide desorption and leaching in soils.展开更多
A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Tw...A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.展开更多
TiO2 doped with C, N and S (TCNS photocatalyst) was prepared by hydrolysis process using titanium iso-propoxide and thiourea. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron micro...TiO2 doped with C, N and S (TCNS photocatalyst) was prepared by hydrolysis process using titanium iso-propoxide and thiourea. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photo electron spectroscopy (XPS), BET surface area, FTIR and diffuse reflectance spectra (DRS). The results showed that the prepared catalysts are anatase type and nanosized par-ticles. The catalysts exhibited stronger absorption in the visible light region with a red shift in the adsorption edge. The photocatalytic activity of TCNS photocatalysts was evaluated by the photocatalytic degradation of isoproturon pesticide in aqueous solution. In the present study the maximum activity was achieved for TCNS5 catalyst at neutral pH with 1 g L-1 catalyst amount and at 1.14 x 10-4 M concentration of the pesticide solution. The TCNS photocatalysts showed higher phtocatalytic activity under solar light irradiation. This is attributed to the synergetic effects of red shift in the absorption edge, higher surface area and the inhibition of charge carrier recombination process.展开更多
Methacrylic acid with isoproturon has been utilized to prepare molecularly imprinted polymeric (MIP) membrane on Whatman filter paper no. 5 for selective electrochemical estimation of isoproturon pesticide. MIP membra...Methacrylic acid with isoproturon has been utilized to prepare molecularly imprinted polymeric (MIP) membrane on Whatman filter paper no. 5 for selective electrochemical estimation of isoproturon pesticide. MIP membrane was prepared by radical polymerization and characterized using Ultra Violet spectrophotometer, Fourier Transform Infra Red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Contact angle study was used to determine the surface energy of the MIP membrane and electrical conductivity measurements were performed by applying a small-amplitude alternating voltage (20 mV) with frequencies varying from 20 Hz to 80 kHz generated by a low-frequency wave form generator. Different isoproturon concentrations in samples were tested and analyzed. Results indicate linear increase in membrane resistance with increasing isoproturon in 10-3 to 10-6 M range. The selectivity of the electrochemical sensor was confirmed by testing isoproturon in presence of the structurally related compounds monouran and diuran. Results reveal highly selective and sensitive sensor, which can be employed for regular estimation of isoproturon in fields.展开更多
建立了一种同柱分离检测44%砜吡草唑·异丙隆悬浮剂中有效成分的高效液相色谱定量方法,确定的色谱条件为250 mm×4.6 mm ODS-C18不锈钢色谱柱和紫外检测器,柱温30℃,甲醇+水溶液(60︰40,体积比)为流动相,检测波长为220 nm。结...建立了一种同柱分离检测44%砜吡草唑·异丙隆悬浮剂中有效成分的高效液相色谱定量方法,确定的色谱条件为250 mm×4.6 mm ODS-C18不锈钢色谱柱和紫外检测器,柱温30℃,甲醇+水溶液(60︰40,体积比)为流动相,检测波长为220 nm。结果表明:在设定的质量浓度范围内,砜吡草唑和异丙隆的线性相关系数r均为0.9999,变异系数分别为1.07%和0.1421%,回收率分别为99.78%和99.50%,说明该方法操作简单、分离效果好,线性关系、准确度和精密度均符合分析的基本要求,可用于制剂产品中砜吡草唑和异丙隆的质量控制。展开更多
为了明确除草剂20%甲二·异丙隆OD对小麦田禾本科杂草的防效及其对作物的安全性,采用室内试验和田间试验评价20%甲二·异丙隆OD的杀草活性及对小麦的安全性。结果表明:室内试验中,当浓度为3 600 g a.i./hm^(2)时,20%甲二·...为了明确除草剂20%甲二·异丙隆OD对小麦田禾本科杂草的防效及其对作物的安全性,采用室内试验和田间试验评价20%甲二·异丙隆OD的杀草活性及对小麦的安全性。结果表明:室内试验中,当浓度为3 600 g a.i./hm^(2)时,20%甲二·异丙隆OD对禾本科杂草看麦娘、菵草和早熟禾的室内鲜重抑制率分别为82.94%、89.22%、94.75%,且对小麦幼苗生长无影响;田间试验中,浓度3 600 g a.i./hm^(2)施药处理30 d后,对小麦田杂草看麦娘、菵草、繁缕的株防效和鲜重防效均大于90%,且对小麦幼苗生长无影响。试验结果表明,20%甲二·异丙隆OD可有效防除小麦田禾本科杂草且对小麦生长无影响,有利于有效解决小麦田草害问题,促进小麦产业节本增效、高质丰产。展开更多
基金partially funded by the National High-Tech R&D Program of China(2006AA06Z356)the National Basic Research Program of China(2007CB936604)the Key Technology Research and Development Program of Anhui Province,China(07010302212)
文摘In order to prevent pesticide leaching from soil, the effects of charcoal amendment on adsorption-desorption of isoproturon in soils were studied and the mechanisms in reducing the loss of isoproturon from soils were suggested. Adsorption-desorption of isoproturon in five different particle sizes of charcoals and three different soils were studied using batch equilibration technique. The results showed that the experimental data were well fitted by the Freundlich empirical equation. Charcoal had a great adsorption capacity for isoproturon, and the smaller the particle size of charcoal, the more the adsorption of isoproturon. The amendment with charcoal could greatly improve the adsorption of isoproturon in soils. The adsorption of isoproturon in soils increased with the rate of charcoal amended （r= 0.9568＊＊, P 〈 0.01）. Desorption of isoproturon from charcoals and soils showed significant hystersis which was shown by the higher adsorption slope （1/nsds） compared to the desorption slope （1/ndes. The hysteresis effects of charcoal on desorption of isoproturon were closely correlated with the content of charcoal in the soils, and the hysteresis index （H） increased with the rate of charcoal amended. Observation of environmental scanning electron microscopy （ESEM） exhibitted the fine pore structure and special surface characteristics of the tested charcoal. Analysis of Fourier transform infrared spectra （FTIR） of isoproturon adsorbed on charcoal suggested probable bonding interactions between isoproturon and charcoal. This research suggests that charcoal amendment may be an effective management practice for controlling pesticide desorption and leaching in soils.
基金This work was financially supported by National Natural Science Foundation of China （20447003）.
文摘A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.
文摘TiO2 doped with C, N and S (TCNS photocatalyst) was prepared by hydrolysis process using titanium iso-propoxide and thiourea. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photo electron spectroscopy (XPS), BET surface area, FTIR and diffuse reflectance spectra (DRS). The results showed that the prepared catalysts are anatase type and nanosized par-ticles. The catalysts exhibited stronger absorption in the visible light region with a red shift in the adsorption edge. The photocatalytic activity of TCNS photocatalysts was evaluated by the photocatalytic degradation of isoproturon pesticide in aqueous solution. In the present study the maximum activity was achieved for TCNS5 catalyst at neutral pH with 1 g L-1 catalyst amount and at 1.14 x 10-4 M concentration of the pesticide solution. The TCNS photocatalysts showed higher phtocatalytic activity under solar light irradiation. This is attributed to the synergetic effects of red shift in the absorption edge, higher surface area and the inhibition of charge carrier recombination process.
文摘Methacrylic acid with isoproturon has been utilized to prepare molecularly imprinted polymeric (MIP) membrane on Whatman filter paper no. 5 for selective electrochemical estimation of isoproturon pesticide. MIP membrane was prepared by radical polymerization and characterized using Ultra Violet spectrophotometer, Fourier Transform Infra Red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Contact angle study was used to determine the surface energy of the MIP membrane and electrical conductivity measurements were performed by applying a small-amplitude alternating voltage (20 mV) with frequencies varying from 20 Hz to 80 kHz generated by a low-frequency wave form generator. Different isoproturon concentrations in samples were tested and analyzed. Results indicate linear increase in membrane resistance with increasing isoproturon in 10-3 to 10-6 M range. The selectivity of the electrochemical sensor was confirmed by testing isoproturon in presence of the structurally related compounds monouran and diuran. Results reveal highly selective and sensitive sensor, which can be employed for regular estimation of isoproturon in fields.
文摘建立了一种同柱分离检测44%砜吡草唑·异丙隆悬浮剂中有效成分的高效液相色谱定量方法,确定的色谱条件为250 mm×4.6 mm ODS-C18不锈钢色谱柱和紫外检测器,柱温30℃,甲醇+水溶液(60︰40,体积比)为流动相,检测波长为220 nm。结果表明:在设定的质量浓度范围内,砜吡草唑和异丙隆的线性相关系数r均为0.9999,变异系数分别为1.07%和0.1421%,回收率分别为99.78%和99.50%,说明该方法操作简单、分离效果好,线性关系、准确度和精密度均符合分析的基本要求,可用于制剂产品中砜吡草唑和异丙隆的质量控制。
文摘为了明确除草剂20%甲二·异丙隆OD对小麦田禾本科杂草的防效及其对作物的安全性,采用室内试验和田间试验评价20%甲二·异丙隆OD的杀草活性及对小麦的安全性。结果表明:室内试验中,当浓度为3 600 g a.i./hm^(2)时,20%甲二·异丙隆OD对禾本科杂草看麦娘、菵草和早熟禾的室内鲜重抑制率分别为82.94%、89.22%、94.75%,且对小麦幼苗生长无影响;田间试验中,浓度3 600 g a.i./hm^(2)施药处理30 d后,对小麦田杂草看麦娘、菵草、繁缕的株防效和鲜重防效均大于90%,且对小麦幼苗生长无影响。试验结果表明,20%甲二·异丙隆OD可有效防除小麦田禾本科杂草且对小麦生长无影响,有利于有效解决小麦田草害问题,促进小麦产业节本增效、高质丰产。
