建立了一种土壤中2,4-D的液相色谱-串联质谱的检测分析方法。样品经酸化乙腈提取,浓缩定容后过0.22μm微孔滤膜,采用色谱柱分离,以乙腈和0.25%甲酸溶液为流动相进行梯度洗脱,采用电喷雾ESI离子源方式和多信号扫描,外标法定量。在10.0~1...建立了一种土壤中2,4-D的液相色谱-串联质谱的检测分析方法。样品经酸化乙腈提取,浓缩定容后过0.22μm微孔滤膜,采用色谱柱分离,以乙腈和0.25%甲酸溶液为流动相进行梯度洗脱,采用电喷雾ESI离子源方式和多信号扫描,外标法定量。在10.0~1000μg/kg的质量浓度范围内,相关系数R^(2)为0.9999,该方法的定量检测限为10.0μg/kg。进行100μg/kg、200μg/kg和1000μg/kg三个不同水平浓度的添加回收试验,2,4-D的回收率在75.91%~98.05%之间,RSD介于5.94%~18.75%之间。该方法操作简单、灵敏度高、快速准确。利用该方法测定土壤中2,4-D残留量,施药后2 h 2,4-D在土壤上的原始附着量为73.4μg/kg,第21天残留量为≤10.0μg/kg,消解率为≥86.38%,半衰期T1/2为5.42 d。展开更多
ABSTRAC Two new complexes [Cd（2,4＇-bpdc）（DPPZ）]2n·n H2O（1） and [Zn（2,4＇-Hbpdc）2（DPPZ）]· H2O（DPPZ = dipyrido[3,2-a：2＇,3＇-c]phenazine, 2,4＇-H2bpdc = 2,4＇-biphenyldicarboxylic acid） have been...ABSTRAC Two new complexes [Cd（2,4＇-bpdc）（DPPZ）]2n·n H2O（1） and [Zn（2,4＇-Hbpdc）2（DPPZ）]· H2O（DPPZ = dipyrido[3,2-a：2＇,3＇-c]phenazine, 2,4＇-H2bpdc = 2,4＇-biphenyldicarboxylic acid） have been hydrothermally synthesized. The structure of complex 1 was determined by single-crystal X-ray diffraction diffraction and further characterized by elemental analysis, IR spectrum, powder X-ray diffraction（XRD） and single-crystal X-ray diffraction. Complex 1 has 1D chains, which are further connected by π-π stacking interactions of neighbouring chains, generating a steady 3D supramolecular structure. Complex 2 shows the isolated mononuclear units, which are further extended to a 2D supramolecular layered structure through π-π stacking interactions and hydrogen bonds. Furthermore, complexes 1 and 2 exhibit green photoluminescent properties at room temperature.展开更多
This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation...This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H202/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.展开更多
A molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-dichlorophenoxyacetic acid （2,4-D） was prepared by a surface imprinting technique in combination with a sol-gel process. The 2,4-D-im...A molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-dichlorophenoxyacetic acid （2,4-D） was prepared by a surface imprinting technique in combination with a sol-gel process. The 2,4-D-imprinted amino-functionalized silica sorbent was characterized by FT-IR, nitrogen adsorption and static adsorption experiments. The selectivity of the sorbent was investigated by a batch competitive binding experiment using an aqueous 2,4-D and 2,4-dichlorophenol （2,4-DCP） mixture or using an aqueous 2,4-D and 2,4- dichlorophenylacetic acid （DPAC） mixture. The largest selectivity coefficient for 2,4-D in the presence of 2,4-DCP was found to be over 18, the largest relative selectivity coefficient between 2,4-D and 2,4-DCP over 9. The static uptake capacity and selectivity coefficient of the 2,4-D-imprinted functionalized sorbent are higher than those of the non-imprinted sorbent. The imprinted functionalized silica gel sorbent offered a fast kinetics for the extraction/stripping of 2,4-D, 73% of binding capacity （200 mg/L 2,4-D onto 20 mg of imprinted sorbent） was obtained within 5 min and the adsorbed 2,4-D can be easily stripped by the mixture solution of ethanol and 6 mol/L HC1 （V：V =1：1）. In a test of five extraction/stripping cycles, the adsorption capacity of the sorbent was all above 93% of that of the fresh sorbent. Experimental result showed the potential of molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-D.展开更多
An experimental comparison of the adsorption properties of hypercrosslinked resin AM-1 modified by phenolic hydroxyl group with Amberlite XAD-4 toward 2,4-dichlorobenzoxyacetic acid was performed. This paper focuses o...An experimental comparison of the adsorption properties of hypercrosslinked resin AM-1 modified by phenolic hydroxyl group with Amberlite XAD-4 toward 2,4-dichlorobenzoxyacetic acid was performed. This paper focuses on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Two isotherm models were used to explain the results. It is seen that the Langmuir equation can give a perfect fit. The adsorption capacities from the different ranges of temperature, the adsorption enthalpy change value and the comparison of desorption conditions lead to the same conclusion that the adsorption of 2,4-dichlorobenzoxyacetic acid from water onto AM-1 is a type of physical and chemical transition.展开更多
A convenient and practical synthetic route for 2,4-dibromo-5-fluorobenzoic acid is described. Two intermediates, 2,4-dibromo-5-fluorobenzonitrile and 2,4-dibromo-5-fluorobenzamide, have not been reported before. This ...A convenient and practical synthetic route for 2,4-dibromo-5-fluorobenzoic acid is described. Two intermediates, 2,4-dibromo-5-fluorobenzonitrile and 2,4-dibromo-5-fluorobenzamide, have not been reported before. This route can be easily industrialized.展开更多
A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sat...A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.展开更多
The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dic...The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd-Fe bimetallic nanoparticles in the presence of humic acid (HA) to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min?1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model.展开更多
文摘建立了一种土壤中2,4-D的液相色谱-串联质谱的检测分析方法。样品经酸化乙腈提取,浓缩定容后过0.22μm微孔滤膜,采用色谱柱分离,以乙腈和0.25%甲酸溶液为流动相进行梯度洗脱,采用电喷雾ESI离子源方式和多信号扫描,外标法定量。在10.0~1000μg/kg的质量浓度范围内,相关系数R^(2)为0.9999,该方法的定量检测限为10.0μg/kg。进行100μg/kg、200μg/kg和1000μg/kg三个不同水平浓度的添加回收试验,2,4-D的回收率在75.91%~98.05%之间,RSD介于5.94%~18.75%之间。该方法操作简单、灵敏度高、快速准确。利用该方法测定土壤中2,4-D残留量,施药后2 h 2,4-D在土壤上的原始附着量为73.4μg/kg,第21天残留量为≤10.0μg/kg,消解率为≥86.38%,半衰期T1/2为5.42 d。
基金Supported by the Program for NNSFC(21407064,21576112)NSF of Jilin Province(20130521019JH)the Science and Technology Development Plan of Siping City(2014052,2015049)
文摘ABSTRAC Two new complexes [Cd（2,4＇-bpdc）（DPPZ）]2n·n H2O（1） and [Zn（2,4＇-Hbpdc）2（DPPZ）]· H2O（DPPZ = dipyrido[3,2-a：2＇,3＇-c]phenazine, 2,4＇-H2bpdc = 2,4＇-biphenyldicarboxylic acid） have been hydrothermally synthesized. The structure of complex 1 was determined by single-crystal X-ray diffraction diffraction and further characterized by elemental analysis, IR spectrum, powder X-ray diffraction（XRD） and single-crystal X-ray diffraction. Complex 1 has 1D chains, which are further connected by π-π stacking interactions of neighbouring chains, generating a steady 3D supramolecular structure. Complex 2 shows the isolated mononuclear units, which are further extended to a 2D supramolecular layered structure through π-π stacking interactions and hydrogen bonds. Furthermore, complexes 1 and 2 exhibit green photoluminescent properties at room temperature.
基金The National Natural Science Foundation of China (No. 50378028)
文摘This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H202/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.
基金supported by the Natural Science Foundation of Zhejiang Province (No.Y505073)the Scientific Project of Zhejiang Province (No.2008C22012)
文摘A molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-dichlorophenoxyacetic acid （2,4-D） was prepared by a surface imprinting technique in combination with a sol-gel process. The 2,4-D-imprinted amino-functionalized silica sorbent was characterized by FT-IR, nitrogen adsorption and static adsorption experiments. The selectivity of the sorbent was investigated by a batch competitive binding experiment using an aqueous 2,4-D and 2,4-dichlorophenol （2,4-DCP） mixture or using an aqueous 2,4-D and 2,4- dichlorophenylacetic acid （DPAC） mixture. The largest selectivity coefficient for 2,4-D in the presence of 2,4-DCP was found to be over 18, the largest relative selectivity coefficient between 2,4-D and 2,4-DCP over 9. The static uptake capacity and selectivity coefficient of the 2,4-D-imprinted functionalized sorbent are higher than those of the non-imprinted sorbent. The imprinted functionalized silica gel sorbent offered a fast kinetics for the extraction/stripping of 2,4-D, 73% of binding capacity （200 mg/L 2,4-D onto 20 mg of imprinted sorbent） was obtained within 5 min and the adsorbed 2,4-D can be easily stripped by the mixture solution of ethanol and 6 mol/L HC1 （V：V =1：1）. In a test of five extraction/stripping cycles, the adsorption capacity of the sorbent was all above 93% of that of the fresh sorbent. Experimental result showed the potential of molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-D.
文摘An experimental comparison of the adsorption properties of hypercrosslinked resin AM-1 modified by phenolic hydroxyl group with Amberlite XAD-4 toward 2,4-dichlorobenzoxyacetic acid was performed. This paper focuses on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Two isotherm models were used to explain the results. It is seen that the Langmuir equation can give a perfect fit. The adsorption capacities from the different ranges of temperature, the adsorption enthalpy change value and the comparison of desorption conditions lead to the same conclusion that the adsorption of 2,4-dichlorobenzoxyacetic acid from water onto AM-1 is a type of physical and chemical transition.
文摘A convenient and practical synthetic route for 2,4-dibromo-5-fluorobenzoic acid is described. Two intermediates, 2,4-dibromo-5-fluorobenzonitrile and 2,4-dibromo-5-fluorobenzamide, have not been reported before. This route can be easily industrialized.
基金Tshe prOject!(39770469) supported by the National Natural Science Foundation of China.
文摘A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.
基金Project supported by the National Natural Science Foundation of China (No. 20407015)the Program for the New Century Excel-lent Talents in University (No. NCET-06-0525), China
文摘The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd-Fe bimetallic nanoparticles in the presence of humic acid (HA) to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min?1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model.
