排序方式: 共有130条查询结果,搜索用时 203 毫秒
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在原子吸收光谱分析中,固体样品直接进样是目前的研究课题之一。本文主要报道作者在分析汞中所进行的固体直接进样技术工作和讨论。在我们研制成功的KT—81型塞曼效应测汞仪中,针对元素汞蒸气压高的特点,用饱和汞蒸气作为汞量标准,实现了固体样品,如土壤、污泥、毛发、煤、食品等汞含量的直接进样测定。汞蒸气一次制备后可长期使用。分析汞时,只要用标准气体任意校验一次就可测量。1~2分钟能分析一个样品,S<0.3ng。r<5%。此法用NBS标准物质验证过。 相似文献
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MinNaYAO YaoQunLI 《中国化学快报》2004,15(1):109-111
Total imernal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl)porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS^4-) and diprotonated (H2TPPS^2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface. 相似文献
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本文介绍了一种快速、简便的测定高含量三醋酸甘油酯的气相色谱法。本法使用10%PEG-20M涂渍在Chromosob W上的色谱柱(2 m×3 mmi.d.),以N_2作载气(40ml/min)氢火焰离子化检测器(FID),柱温180℃,汽化温度200℃,能很好地将三醋酸甘油酯与二醋酸甘油酯分离。并选用十二醇为内标物测定了十批合成样品中的三醋酸甘油酯含量,变异系数<0.4%。 相似文献
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Rao RN Alvi SN Rao BN;HPLC Group Analytical Chemistry Division 《Journal of chromatography. A》2005,1076(1-2):189-192
A simple and rapid preparative high-performance liquid chromatography (HPLC) method has been developed to isolate and characterize some minor impurities of astaxanthin using a normal-phase Lichrosorb silica column with n-hexane-acetone-tetrahydrofuran (90:2:8, v/v/v) as mobile-phase and detection at 475 nm. The isolated impurities were characterized as astacene, dehydro astacene and apoastaxanthinal by UV-vis, ESI-MS, 1H and 13C NMR spectroscopy and the molecular structures were assigned. The impurities collected using the developed conditions were over 98% pure. 相似文献
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QinZHAO RuoYUAN ChangLiMO YaQinCHAI XiaZHONG 《中国化学快报》2004,15(2):208-211
Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18μmol/L glucose with detection limit of 0.5μmol/L glucose. 相似文献
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WANG Wei & ZHU Jun-Jie State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry Chemical Engineering Nanjing University Nanjing China 《中国科学B辑(英文版)》2011,(8)
This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed. 相似文献
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Analytical Method Committee The Royal Society of Chemistry 《Accreditation and quality assurance》2010,15(3):189-191
Willink’s paper, “Uncertainty in repeated measurement of a small non-negative quantity: explanation and discussion of Bayesian
methodology” provides a clear exposition of the Bayesian paradigm but unfortunately reads like a rebuttal of a previous paper
from the AMC: the reader is left with the impression that the AMC is recommending a procedure that performs poorly. The AMC
here refutes any such impression by presenting a balanced assessment of the strengths and weaknesses of the Bayesian and frequentist
approaches to formulating the uncertainty of small non-negative quantities. 相似文献