Interference filters are used in many fields,such as radiometric and photometric measurements and SO on.For high-accuracy measurement of spectral transmittance of interference filter,an automated,single—beam spectrop...Interference filters are used in many fields,such as radiometric and photometric measurements and SO on.For high-accuracy measurement of spectral transmittance of interference filter,an automated,single—beam spectrophotometer based on DK242 double monochromator is developed,whose input optics and output optics are designed independently.In order to improve the accuracy of measurement,the averaging detector unit with a silicon detector is introduced into the measurement system.The source of the uncertainties includes wavelength calibration,detector nonlinearity,system instability.beam displacement and SO on.A total uncertainty of 8.78x10^(-3)is estimated for transmitance measurements of interference filters,which meets the requirement of the design.展开更多
The ultraviolet-visible light spectrophotometer method was adopted to determine thioglucoside in cabbage with the seeds.Individual plant of cabbage was used as test materials,palladium chloride as complexing agent and...The ultraviolet-visible light spectrophotometer method was adopted to determine thioglucoside in cabbage with the seeds.Individual plant of cabbage was used as test materials,palladium chloride as complexing agent and sodium cellulose glycolate as dispersing agent.The results showed that palladiumd thioglucoside method could be taken as a quick,easy and precise quantitative analysis method to determine thioglucoside in cabbage.展开更多
The metal contents of Nigerian coal minerals were analyzed using an atomic absorption spectrophotometer. Calcium, Na, and Fe occurred as the major elements with concentrations ranging from 9 782 μg/g for Ca to 432 μ...The metal contents of Nigerian coal minerals were analyzed using an atomic absorption spectrophotometer. Calcium, Na, and Fe occurred as the major elements with concentrations ranging from 9 782 μg/g for Ca to 432 μg/g for Na whereas K, Mg, Mn, Ni, Cr, Zn, Pb, and Cu, which occurred at trace levels ranged from 673.73 μg/g for Mg to 2.97 μg/g for Mn. The results of the quantitative analysis of porphyrins extracted from the coal minerals showed that Onyeama coal has the highest amount of porphyrins (ca～0.96 μg/g) while Okpara has the lowest (ca～0.30 μg/g). The porphyrins were qualitatively characterized by a combination of thin layer chromatography (TLC), infrared, and ultraviolet-visible spectrophotometers. The results of the mid infrared analysis (MIR) showed the presence of absorption bands at 3 440 cm～1～3 450 cm-1 and 1 640 cm-1～1 680 cm-1 , which are owing to the stretching vibrations of N ─ H and C─ C of aromatics, with C─ H out of plane (oop) bending vibrations at wavenumbers less than 900 cm-1, all of which are characteristic absorptions of porphyrin free base. The ultraviolet-visible data showed prominent peaks at ～400 nm(Soret band) and at wavelength ranges of 535 nm～550 nm(β-band) and 565 nm～ 600 nm (α-band) for the coal porphyrins analyzed. The geochemical significance of the metals and porphyrins in coal minerals are discussed.展开更多
The UV-Vis and infrared(IR)absorption spectra of organophosphorus(OP)pesticides have been studied.A correlation in spectra was developed to optimize the OP pesticides in the environments.The spectroscopic(UV-Vis and I...The UV-Vis and infrared(IR)absorption spectra of organophosphorus(OP)pesticides have been studied.A correlation in spectra was developed to optimize the OP pesticides in the environments.The spectroscopic(UV-Vis and IR)spectrum of OP pesticides like methyl parathion,malathion and parathion has been interpreted in detail.A complete calculation of the normal frequencies and absolute intensities of UV-Vis and IR absorption bands are interpreted with the help of corresponding experimental data.In the colorimetric reactions,the bands appear at 2 077,1 637,1 455,1 015,655cm^(-1) for malathion;2 081,1 639,1 316,1 015,794,683cm^(-1) for parathion;2 078,1 632,1 032,794cm^(-1) for methyl parathion were used for quantitative or qualitative analysis.All these IR spectra were acquired by averaging 100 scans at a resolution of 4cm^(-1).It is determined experimentally in the region 200~450nm for UV-Vis absorption bands and in the region 400~4 000cm^(-1) for IR absorption bands.It is concluded that the mainly optically active groups(P—OH, C=O,P=O, C—O—C,P—O—C, P=S, —OH)present in pesticides which are responsible in change in significant data for quantitative and qualitative analysis.The various optical properties like wavelength,band energy,wave number,and frequency,also are calculated.展开更多
文摘Interference filters are used in many fields,such as radiometric and photometric measurements and SO on.For high-accuracy measurement of spectral transmittance of interference filter,an automated,single—beam spectrophotometer based on DK242 double monochromator is developed,whose input optics and output optics are designed independently.In order to improve the accuracy of measurement,the averaging detector unit with a silicon detector is introduced into the measurement system.The source of the uncertainties includes wavelength calibration,detector nonlinearity,system instability.beam displacement and SO on.A total uncertainty of 8.78x10^(-3)is estimated for transmitance measurements of interference filters,which meets the requirement of the design.
文摘The ultraviolet-visible light spectrophotometer method was adopted to determine thioglucoside in cabbage with the seeds.Individual plant of cabbage was used as test materials,palladium chloride as complexing agent and sodium cellulose glycolate as dispersing agent.The results showed that palladiumd thioglucoside method could be taken as a quick,easy and precise quantitative analysis method to determine thioglucoside in cabbage.
文摘The metal contents of Nigerian coal minerals were analyzed using an atomic absorption spectrophotometer. Calcium, Na, and Fe occurred as the major elements with concentrations ranging from 9 782 μg/g for Ca to 432 μg/g for Na whereas K, Mg, Mn, Ni, Cr, Zn, Pb, and Cu, which occurred at trace levels ranged from 673.73 μg/g for Mg to 2.97 μg/g for Mn. The results of the quantitative analysis of porphyrins extracted from the coal minerals showed that Onyeama coal has the highest amount of porphyrins (ca～0.96 μg/g) while Okpara has the lowest (ca～0.30 μg/g). The porphyrins were qualitatively characterized by a combination of thin layer chromatography (TLC), infrared, and ultraviolet-visible spectrophotometers. The results of the mid infrared analysis (MIR) showed the presence of absorption bands at 3 440 cm～1～3 450 cm-1 and 1 640 cm-1～1 680 cm-1 , which are owing to the stretching vibrations of N ─ H and C─ C of aromatics, with C─ H out of plane (oop) bending vibrations at wavenumbers less than 900 cm-1, all of which are characteristic absorptions of porphyrin free base. The ultraviolet-visible data showed prominent peaks at ～400 nm(Soret band) and at wavelength ranges of 535 nm～550 nm(β-band) and 565 nm～ 600 nm (α-band) for the coal porphyrins analyzed. The geochemical significance of the metals and porphyrins in coal minerals are discussed.
基金worked in funding projects from DST,New Delhi for extensive research in the area of nano-bio molecular spectroscopy and sensor technology development
文摘The UV-Vis and infrared(IR)absorption spectra of organophosphorus(OP)pesticides have been studied.A correlation in spectra was developed to optimize the OP pesticides in the environments.The spectroscopic(UV-Vis and IR)spectrum of OP pesticides like methyl parathion,malathion and parathion has been interpreted in detail.A complete calculation of the normal frequencies and absolute intensities of UV-Vis and IR absorption bands are interpreted with the help of corresponding experimental data.In the colorimetric reactions,the bands appear at 2 077,1 637,1 455,1 015,655cm^(-1) for malathion;2 081,1 639,1 316,1 015,794,683cm^(-1) for parathion;2 078,1 632,1 032,794cm^(-1) for methyl parathion were used for quantitative or qualitative analysis.All these IR spectra were acquired by averaging 100 scans at a resolution of 4cm^(-1).It is determined experimentally in the region 200~450nm for UV-Vis absorption bands and in the region 400~4 000cm^(-1) for IR absorption bands.It is concluded that the mainly optically active groups(P—OH, C=O,P=O, C—O—C,P—O—C, P=S, —OH)present in pesticides which are responsible in change in significant data for quantitative and qualitative analysis.The various optical properties like wavelength,band energy,wave number,and frequency,also are calculated.
