A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work. The effects of pH, concentratio...A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work. The effects of pH, concentration of surfactant, and equilibration time on cloud point extraction were discussed. The enhancement factor of 20 and the detection limit of 0.039 μg/L were obtained for mercury with relative standard deviation of 4.8% （n = 11）.展开更多
While engineered nanoparticles are widely used and maybe eventually released into the environment,natural nanoparticles are also commonly found in the Earth system.Nanoparticles may critically affect the geochemical m...While engineered nanoparticles are widely used and maybe eventually released into the environment,natural nanoparticles are also commonly found in the Earth system.Nanoparticles may critically affect the geochemical migration of associated elements and pose potential threats to the ecological environment.It is necessary to establish an accurate and reliable method for measuring the concentration of nanoparticles.AAS is one of the most commonly used methods for the concentration determination of nanoparticles.However,till now,there has been no systematic report on how experimental variables affect AAS measurements.In this study,we used gold nanoparticles(AuNPs) as an example and studied the influences of a list of factors on the concentration determination of AuNPs by AAS,including digestion method,ionization interference,acidic medium,background correction method,and organic matter.We demonstrate that all these factors may have varying degrees of influence on the measured gold concentrations.When the gold colloid is digested at room temperature for more than 8 h or at 60℃ for more than 2 h,and the system contains a low concentration of organic matter,AAS can accurately measure the AuNP concentration at ppm-level.The deuterium lamp background deduction method is not recommended to use for samples with lower gold concentrations.展开更多
We report on the use of titanium dioxide nanoparticles (NPs) coated with poly-thiophene for the preconcentration of copper and silverions. The NPs were prepared by first modifying the surface of TiO2 NPs with vinyl gr...We report on the use of titanium dioxide nanoparticles (NPs) coated with poly-thiophene for the preconcentration of copper and silverions. The NPs were prepared by first modifying the surface of TiO2 NPs with vinyl groups and then copolymerizing them with vinyl thiophen. The resulting TiO2-polythiophene core-shell NPs were characterized by thermogravimetry, differential thermal analysis, scanning electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction. The experimental conditions such as pH value, adsorption and desorption time, type, concentration and volume of the eluent, break through volume, and effect of potentially interfering ions were optimized. The ions were then desorbed with hydrochloric acid and determined by FAAS. The limits of detection are 0.4 and 1.2 μg·L_1 for Cu(II) and Ag(I), respectively, and recoveries and precisions are >98.0%展开更多
The contents of Mn,Zn and Cu,three essential trace elements for human body,in Laminaria japonica,Auricularia auricula( L. ex Hook.) Underwood,Porphyra,Cucurbita pepo L.,Spinacia oleracea L. and Coriandrum sativum were...The contents of Mn,Zn and Cu,three essential trace elements for human body,in Laminaria japonica,Auricularia auricula( L. ex Hook.) Underwood,Porphyra,Cucurbita pepo L.,Spinacia oleracea L. and Coriandrum sativum were determined by atomic absorption spectrophotometry. Vegetable samples were processed by wet digestion. The results showed that among the six vegetables,Mn had the highest content in A. auricula( 26. 60 μg/g) and the lowest content in C. pepo( 1. 22 μg/g); Zn had the highest content in Porphyra( 38. 07 μg/g)and the lowest content in L. japonica( 10. 32 μg/g); and Cu had the highest content in Porphyra( 10. 35 μg/g) and the lowest content in S. oleracea( 0. 61 μg/g). Each determination was repeated five times. The value of RSD was less than 10%,indicating high accuracy.展开更多
文摘A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work. The effects of pH, concentration of surfactant, and equilibration time on cloud point extraction were discussed. The enhancement factor of 20 and the detection limit of 0.039 μg/L were obtained for mercury with relative standard deviation of 4.8% （n = 11）.
基金supported by Guizhou Provincial Science and Technology Foundation (Qian Sci.Co.ZK[2021] No.198)Doctoral Research Startup Project in 2017 of Guizhou Normal University in China+1 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences (Grant No.XDB41000000)the National Natural Science Foundation of China (41872046,41173074 and 42063008)。
文摘While engineered nanoparticles are widely used and maybe eventually released into the environment,natural nanoparticles are also commonly found in the Earth system.Nanoparticles may critically affect the geochemical migration of associated elements and pose potential threats to the ecological environment.It is necessary to establish an accurate and reliable method for measuring the concentration of nanoparticles.AAS is one of the most commonly used methods for the concentration determination of nanoparticles.However,till now,there has been no systematic report on how experimental variables affect AAS measurements.In this study,we used gold nanoparticles(AuNPs) as an example and studied the influences of a list of factors on the concentration determination of AuNPs by AAS,including digestion method,ionization interference,acidic medium,background correction method,and organic matter.We demonstrate that all these factors may have varying degrees of influence on the measured gold concentrations.When the gold colloid is digested at room temperature for more than 8 h or at 60℃ for more than 2 h,and the system contains a low concentration of organic matter,AAS can accurately measure the AuNP concentration at ppm-level.The deuterium lamp background deduction method is not recommended to use for samples with lower gold concentrations.
文摘We report on the use of titanium dioxide nanoparticles (NPs) coated with poly-thiophene for the preconcentration of copper and silverions. The NPs were prepared by first modifying the surface of TiO2 NPs with vinyl groups and then copolymerizing them with vinyl thiophen. The resulting TiO2-polythiophene core-shell NPs were characterized by thermogravimetry, differential thermal analysis, scanning electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction. The experimental conditions such as pH value, adsorption and desorption time, type, concentration and volume of the eluent, break through volume, and effect of potentially interfering ions were optimized. The ions were then desorbed with hydrochloric acid and determined by FAAS. The limits of detection are 0.4 and 1.2 μg·L_1 for Cu(II) and Ag(I), respectively, and recoveries and precisions are >98.0%
文摘The contents of Mn,Zn and Cu,three essential trace elements for human body,in Laminaria japonica,Auricularia auricula( L. ex Hook.) Underwood,Porphyra,Cucurbita pepo L.,Spinacia oleracea L. and Coriandrum sativum were determined by atomic absorption spectrophotometry. Vegetable samples were processed by wet digestion. The results showed that among the six vegetables,Mn had the highest content in A. auricula( 26. 60 μg/g) and the lowest content in C. pepo( 1. 22 μg/g); Zn had the highest content in Porphyra( 38. 07 μg/g)and the lowest content in L. japonica( 10. 32 μg/g); and Cu had the highest content in Porphyra( 10. 35 μg/g) and the lowest content in S. oleracea( 0. 61 μg/g). Each determination was repeated five times. The value of RSD was less than 10%,indicating high accuracy.
