Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new met...Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.展开更多
It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an...It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.展开更多
Solid surface fluorescence (SSF) spectra of fibrinogen (FG) adsorbed on a glass surface were measured. For comparison, solution fluorescence (SF) spectra of native, thermally denatured, urea denatured FG solution wit...Solid surface fluorescence (SSF) spectra of fibrinogen (FG) adsorbed on a glass surface were measured. For comparison, solution fluorescence (SF) spectra of native, thermally denatured, urea denatured FG solution with FG desorbed from a glass surface and the SSF spectra of native FG powder were recorded. To analyze the structural changes induced by the surface adsorption, all the aqueous samples mentioned above were analyzed by circular dichroism (CD) spectroscopy. The results demonstrated that the structural changes of FG induced by glass adsorption caused changes in the spectroscopic features of the SSF spectra, especially in the excitation (EX) spectra. It is suggested that SSF spectroscopy may be a useful tool for studying the structures of surface/interface biomolecules and for evaluating the biocompatibility of biomaterials.展开更多
The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthra...The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthraquinone (Quinizarine, QZ) as a fluorosphore. Biological samples were tested using commercial reagent strips and clinical parameters. Al(III) was determined complexing with QZ followed by a solid phase extraction step using Nylon membranes as a solid support. The analyte was subsequently quantified by solid surface fluorescence (SSF, λem= 573, λexc= 490) with a detection limit of 0.88 μg L-1 and quantification limit of 2.69 μg L-1. The calibration curve was linear from 2.69 to 499.13 μg L-1 Al(III) (R2 = 0.9973). Urine samples were successfully analysed with an average recovery close to 100%. Solid phase extraction step showed efficacy to eliminate foreign ions and the highly fluorescent matrix own of urine. Results were validated by electrothermal atomic absorption spectrometry (ETAAS) with an adequate concordance. The new methodology has low operation cost with simple instrumentation and without organic solvent.展开更多
建立了表面分子印迹-固相荧光法测定农药西维因(Carbaryl)。以甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸(EGDMA)为交联剂,乙腈为致孔剂,2,2’-偶氮二异丁腈(AIBN)为引发剂,硅胶为载体,制备出一种以西维因为模板分子的表面分子印迹...建立了表面分子印迹-固相荧光法测定农药西维因(Carbaryl)。以甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸(EGDMA)为交联剂,乙腈为致孔剂,2,2’-偶氮二异丁腈(AIBN)为引发剂,硅胶为载体,制备出一种以西维因为模板分子的表面分子印迹聚合物(Carbaryl-SMIPs)。将该聚合物的粉末包埋在凝胶中,通过对凝胶基底的优化,得到了具有特异性识别功能的固相荧光材料(Carbaryl-SMIPs-PVA),应用于对西维因的检测。结果表明,在凝胶基底制备过程中当聚乙烯醇(PVA)溶液的质量分数为6%,Carbaryl-SMIPs的添加量为5 mg/6 mL PVA时,Carbaryl-SMIPs-PVA具有良好的吸附性能,实现了对果蔬表面西维因的快速检测。展开更多
文摘Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.
基金Supported by the NationalNaturalScience Foundation of China( No. 2 0 175 0 1) and U niversity Key Teachers Programdirected under the Ministry of Education ofP.R.China( No. 2 0 0 0 - 6 5 )
文摘It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.
文摘Solid surface fluorescence (SSF) spectra of fibrinogen (FG) adsorbed on a glass surface were measured. For comparison, solution fluorescence (SF) spectra of native, thermally denatured, urea denatured FG solution with FG desorbed from a glass surface and the SSF spectra of native FG powder were recorded. To analyze the structural changes induced by the surface adsorption, all the aqueous samples mentioned above were analyzed by circular dichroism (CD) spectroscopy. The results demonstrated that the structural changes of FG induced by glass adsorption caused changes in the spectroscopic features of the SSF spectra, especially in the excitation (EX) spectra. It is suggested that SSF spectroscopy may be a useful tool for studying the structures of surface/interface biomolecules and for evaluating the biocompatibility of biomaterials.
文摘The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthraquinone (Quinizarine, QZ) as a fluorosphore. Biological samples were tested using commercial reagent strips and clinical parameters. Al(III) was determined complexing with QZ followed by a solid phase extraction step using Nylon membranes as a solid support. The analyte was subsequently quantified by solid surface fluorescence (SSF, λem= 573, λexc= 490) with a detection limit of 0.88 μg L-1 and quantification limit of 2.69 μg L-1. The calibration curve was linear from 2.69 to 499.13 μg L-1 Al(III) (R2 = 0.9973). Urine samples were successfully analysed with an average recovery close to 100%. Solid phase extraction step showed efficacy to eliminate foreign ions and the highly fluorescent matrix own of urine. Results were validated by electrothermal atomic absorption spectrometry (ETAAS) with an adequate concordance. The new methodology has low operation cost with simple instrumentation and without organic solvent.
文摘建立了表面分子印迹-固相荧光法测定农药西维因(Carbaryl)。以甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸(EGDMA)为交联剂,乙腈为致孔剂,2,2’-偶氮二异丁腈(AIBN)为引发剂,硅胶为载体,制备出一种以西维因为模板分子的表面分子印迹聚合物(Carbaryl-SMIPs)。将该聚合物的粉末包埋在凝胶中,通过对凝胶基底的优化,得到了具有特异性识别功能的固相荧光材料(Carbaryl-SMIPs-PVA),应用于对西维因的检测。结果表明,在凝胶基底制备过程中当聚乙烯醇(PVA)溶液的质量分数为6%,Carbaryl-SMIPs的添加量为5 mg/6 mL PVA时,Carbaryl-SMIPs-PVA具有良好的吸附性能,实现了对果蔬表面西维因的快速检测。
