An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four ty...An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated.展开更多
The technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater of Lake Chaohu, a shallow eutrophication la...The technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater of Lake Chaohu, a shallow eutrophication lake. Three kinds of DGT probes (with three thicknesses of diffusive gel: 0.38 mm, 0.78 mm and 1.18 mm) measured vertical concentration and induced flux from solid to solution phase which had intricate variations with depth. The results indicated that higher concentrations and induced fluxes of DRP were achieved by using DGT probe with thicker diffusion layer (CDGT1.18 > CDGT0.78 > CDGT0.38) and relatively stable DRP concentration profiles using DGT probes with 0.78 mm diffusive gel were obtained in each sediment core. The DRP concentrations displayed a clear gradient from Core C1 to Core C3 in sediment porewaters due to different sources and exchange degrees of reactive phosphorus. Compared to the concentrations obtained by the centrifugation technique, the concentrations of DRP resulting from the DGT technique were higher because some dissolved reactive phosphorus compounds have always been neglected using conventional centrifugation method.展开更多
以EPO抗体修饰的Fe_(3)O_(4)粉末-聚丙烯酰胺凝胶为结合相,明胶凝胶为扩散层,通过薄膜扩散梯度技术(DGT)与紫外光谱法,对去离子水、人体尿液中的rhEPO进行富集和检测的实验研究。在25℃、常压环境下,DGT中结合相的饱和富集容量为0.0758...以EPO抗体修饰的Fe_(3)O_(4)粉末-聚丙烯酰胺凝胶为结合相,明胶凝胶为扩散层,通过薄膜扩散梯度技术(DGT)与紫外光谱法,对去离子水、人体尿液中的rhEPO进行富集和检测的实验研究。在25℃、常压环境下,DGT中结合相的饱和富集容量为0.0758μg cm^(2),当pH值为5.5~8.0、无机盐浓度为0.3%~1.5%时,rhEPO的检测回收率基本不受影响。对质量浓度为6~15 ng mL的rhEPO水溶液进行检测时,rhEPO检测回收率的平均值为81.9%;对质量浓度为5~20 ng mL的rhEPO人体尿液进行检测时,rhEPO检测回收率的平均值为79.8%。展开更多
薄膜扩散梯度技术（Diffusive gradients in thin films technique,DGT）是近年来应用于自然水体、沉积物和土壤中活性磷原位测定的一种新技术。利用含碱式碳酸镁的聚丙烯酰胺凝胶膜为DGT新结合相,探讨了初始浓度、放置时间、p H值及离...薄膜扩散梯度技术（Diffusive gradients in thin films technique,DGT）是近年来应用于自然水体、沉积物和土壤中活性磷原位测定的一种新技术。利用含碱式碳酸镁的聚丙烯酰胺凝胶膜为DGT新结合相,探讨了初始浓度、放置时间、p H值及离子强度对组装后DGT吸附性能的影响。用10 m L 0.25 mol/L H2SO4对结合相进行洗脱,洗脱率为85%±5%。组装后DGT对磷的测定不受溶液p H值（4.10~9.15）和离子强度（0.001~0.05 mol/L）的影响。在温度25℃,p H 7.00,磷初始浓度为2 mg/L时,DGT对磷的最大吸附容量为20.4μg。初始磷浓度为0.001~20 mg/L时,新DGT测定值与磷钼蓝比色法测定值一致。本方法对磷的检出限为102.4 ng/L。将碱式碳酸镁-DGT和商品化的Ferrihydrite-DGT应用于合成海水、厦门近岸海水、易海、巢湖水和南淝河中的对比检测,结果表明,碱式碳酸镁-DGT能更准确测定不同水体中磷浓度。展开更多
A diffusive gradients in thin films （DGT） technique based on hydrous zirconium oxide （Zr-oxide） has been recently developed for the measurement of dissolved reactive phosphate （DRP）. In this study, the detailed ...A diffusive gradients in thin films （DGT） technique based on hydrous zirconium oxide （Zr-oxide） has been recently developed for the measurement of dissolved reactive phosphate （DRP）. In this study, the detailed performance of the DGT technique is reported. Spiking experiments revealed that several orthophosphate monoester compounds contributed to the Zr-oxide DGT measurements of DRP. However, such a phenomenon is unlikely to occur during field conditions due to the low concentration of organic P in typical natural waters. The presence of Cl- （up to 106 g/L）, SO42- （up to 16 g/L）, HCO3- （up to 817 g/L）, and AsO2- and AsO 3 4 （both up to 1 mg As/L） in solutions had negligible effects on the measurement of DRP. The threshold concentrations of Cl-, SO42- and HCO3- have been increased from previous reports for the measurements of DRP using other adsorbent-based DGT techniques. The capacity for DGT measurements of DRP decreased with increasing solution pH （4.2-9.2）. The lowest capacity （95 μg P/m2 at pH 9.2） was still greater than that of other DGT techniques that are usually used for the measurement of DRP （2-12 μg P/cm2 ）. The Zr-oxide binding gel could be stored for up to 2 years without any aging effect. This period of validity was considerably longer than the ferrihydrite binding gel that is commonly used in present DGT devices （6 months）. The field application revealed that the concentrations of DRP measured in three fresh water samples using the Zr-oxide DGT technique were in agreement with those of the traditional colorimetric method.展开更多
文摘An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated.
文摘The technique of DGT (diffusive gradients in thin films) was applied to obtain high-resolution vertical profiles of dissolved reactive phosphorus (DRP) in sediment porewater of Lake Chaohu, a shallow eutrophication lake. Three kinds of DGT probes (with three thicknesses of diffusive gel: 0.38 mm, 0.78 mm and 1.18 mm) measured vertical concentration and induced flux from solid to solution phase which had intricate variations with depth. The results indicated that higher concentrations and induced fluxes of DRP were achieved by using DGT probe with thicker diffusion layer (CDGT1.18 > CDGT0.78 > CDGT0.38) and relatively stable DRP concentration profiles using DGT probes with 0.78 mm diffusive gel were obtained in each sediment core. The DRP concentrations displayed a clear gradient from Core C1 to Core C3 in sediment porewaters due to different sources and exchange degrees of reactive phosphorus. Compared to the concentrations obtained by the centrifugation technique, the concentrations of DRP resulting from the DGT technique were higher because some dissolved reactive phosphorus compounds have always been neglected using conventional centrifugation method.
文摘以EPO抗体修饰的Fe_(3)O_(4)粉末-聚丙烯酰胺凝胶为结合相,明胶凝胶为扩散层,通过薄膜扩散梯度技术(DGT)与紫外光谱法,对去离子水、人体尿液中的rhEPO进行富集和检测的实验研究。在25℃、常压环境下,DGT中结合相的饱和富集容量为0.0758μg cm^(2),当pH值为5.5~8.0、无机盐浓度为0.3%~1.5%时,rhEPO的检测回收率基本不受影响。对质量浓度为6~15 ng mL的rhEPO水溶液进行检测时,rhEPO检测回收率的平均值为81.9%;对质量浓度为5~20 ng mL的rhEPO人体尿液进行检测时,rhEPO检测回收率的平均值为79.8%。
文摘薄膜扩散梯度技术（Diffusive gradients in thin films technique,DGT）是近年来应用于自然水体、沉积物和土壤中活性磷原位测定的一种新技术。利用含碱式碳酸镁的聚丙烯酰胺凝胶膜为DGT新结合相,探讨了初始浓度、放置时间、p H值及离子强度对组装后DGT吸附性能的影响。用10 m L 0.25 mol/L H2SO4对结合相进行洗脱,洗脱率为85%±5%。组装后DGT对磷的测定不受溶液p H值（4.10~9.15）和离子强度（0.001~0.05 mol/L）的影响。在温度25℃,p H 7.00,磷初始浓度为2 mg/L时,DGT对磷的最大吸附容量为20.4μg。初始磷浓度为0.001~20 mg/L时,新DGT测定值与磷钼蓝比色法测定值一致。本方法对磷的检出限为102.4 ng/L。将碱式碳酸镁-DGT和商品化的Ferrihydrite-DGT应用于合成海水、厦门近岸海水、易海、巢湖水和南淝河中的对比检测,结果表明,碱式碳酸镁-DGT能更准确测定不同水体中磷浓度。
基金sponsored by the National Natural Scientific Foundation of China (No. 41001334, 41001325)the Project of Knowledge Innovation for the 3rd period, the Chinese Academy of Sciences (No. KZCX2-YW-JS304)the Natural Scientific Foundation of Jiangsu Province, China (No. BK2010606)
文摘A diffusive gradients in thin films （DGT） technique based on hydrous zirconium oxide （Zr-oxide） has been recently developed for the measurement of dissolved reactive phosphate （DRP）. In this study, the detailed performance of the DGT technique is reported. Spiking experiments revealed that several orthophosphate monoester compounds contributed to the Zr-oxide DGT measurements of DRP. However, such a phenomenon is unlikely to occur during field conditions due to the low concentration of organic P in typical natural waters. The presence of Cl- （up to 106 g/L）, SO42- （up to 16 g/L）, HCO3- （up to 817 g/L）, and AsO2- and AsO 3 4 （both up to 1 mg As/L） in solutions had negligible effects on the measurement of DRP. The threshold concentrations of Cl-, SO42- and HCO3- have been increased from previous reports for the measurements of DRP using other adsorbent-based DGT techniques. The capacity for DGT measurements of DRP decreased with increasing solution pH （4.2-9.2）. The lowest capacity （95 μg P/m2 at pH 9.2） was still greater than that of other DGT techniques that are usually used for the measurement of DRP （2-12 μg P/cm2 ）. The Zr-oxide binding gel could be stored for up to 2 years without any aging effect. This period of validity was considerably longer than the ferrihydrite binding gel that is commonly used in present DGT devices （6 months）. The field application revealed that the concentrations of DRP measured in three fresh water samples using the Zr-oxide DGT technique were in agreement with those of the traditional colorimetric method.
