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排序方式: 共有204条查询结果,搜索用时 15 毫秒
51.
Jian‐Hong Wu Kuang Xiao Yong Zhao Wei‐Ping Zhang Lin Guo Yu‐Qi Feng 《Journal of separation science》2010,33(15):2361-2368
Ceria‐zirconia composites at different molar ratios were synthesized. Several methods were used to characterize these composites, including X‐ray photoelectron spectroscopy, surface area and surface acid‐base property detection. A one‐step method for isolation and identification of phosphopeptides from peptide mixture was created using these ceria‐zirconia composites. Using tryptic digest of standard phosphorylated protein, we have shown that these enrichment and dephosphorylation activities are effective. The adsorption capacity and catalytic property of ceria‐zirconia composites at different molar ratios and calcinated temperatures were studied. In combination with MALDI‐TOF‐based peptide mass finger printing technique, we have established a method to utilize the enrichment/dephosphorylation dual properties of these ceria‐zirconia composites for the analysis of phosphoprotein in nonfat milk successfully. 相似文献
52.
Glutathione modified magnetic nanoparticles (Fe3O4@Au-GSH) were synthesized through a simple process and exploited to enrich glycopeptides from complex samples. 相似文献
53.
液体样品中铬的价态和微量分析方法的研究进展 总被引:8,自引:0,他引:8
文章对液体样中铬的价态、微量铬的分离富集和分析方法进行综述,引用文献60篇。 相似文献
54.
我国环境中有机污染物分析方法及痕量富集技术的进展 总被引:1,自引:0,他引:1
对有机污染物分析在近年进展作了评述。其主要内容涉及试样的预处理技术(如顶空法,吹扫-捕集法,固相萃取,半透膜等技术),各化合物的适用及有效的分析方法或仪器(如GC,HPLC及GC/MS等)以及各种技术及方法的联用技术等(引述文献37篇)。 相似文献
55.
利用改性皮革胶原纤维作为水体中重金属离子的富集材料,研究了该材料对水体中Cd^2+、Cr^3+、Pb^2+、Ni^2+、Co^2+等重金属离子的分离富集能力。实验表明,在pH4~7的酸性和中性的条件下,该材料对重金属离子的富集量最大。其中,Cr^3+在pH4~5时富集率达到100%;Co^2+、Ni^2+在pH6~7时富集率达到100%左右;Cd^2+和Pb^2+在pH8~9时富集率达到100%左右;在混和溶液中和存在络合配位体时,可以通过控制待测液的酸度对水体中的重金属离子进行选择性吸附。通过样品的分析,可以利用改性皮革胶原纤维作为测定水体中的重金属离子的吸附剂,对水体中的重金属离子进行分析测定。 相似文献
56.
Pb,Cu和Zn在自然水体生物膜中铁/ 锰氧化物等组分上的富集规律 总被引:2,自引:0,他引:2
用选择性萃取法萃取天然基质采集的生物膜中的铁/锰氧化物, 考察生物膜上铁/锰氧化物对水体中Pb, Cu及Zn的富集作用. 结果表明, 锰氧化物对生物膜富集Pb起主要作用, 而铁氧化物和除铁/锰氧化物以外的以有机质为主的其它组分的作用很小; 膜上其它组分对Cu的富集贡献较大, 锰氧化物的贡献与铁氧化物的接近; 锰氧化物对Zn的富集贡献最大, 铁氧化物和其它组分的贡献比较接近. 锰氧化物对Pb, Cu及Zn的富集能力分别高于铁氧化物的富集能力, 铁氧化物和锰氧化物对3种金属富集能力的大小顺序分别是Zn>Cu>Pb和Zn>Pb≥Cu. 相似文献
57.
58.
Magnetically driven separation techniques have received considerable attention in recent decade because of their great potential application. In this study, we investigate the application of an unmodified layered magnetic Fe/Fe2O3 nanoscavenger for the analytical enrichment and determination of sub-parts per billion concentrations of Cd(II), Pb(II), Ni(II), Cr(VI) and As(V) from water samples. The synthesized nanoscavenger was characterized by BET, TGA, XRD and IR and the parameters influencing the extraction and recovery of the preconcentration process were assessed by atomic absorption spectrometry. The possible mechanism of the enrichment of heavy metals on Fe/Fe2O3 was proposed, which involved the dominant adsorption and reduction. The nanoscale size offers large surface area and high reactivity of sorption and reduction reactions. The obtained limits of detection for the metals studied were in the range of 20–125 ng L−1 and the applicability of the nanomaterial was verified using a real sample matrix. The method is environmentally friendly as only 15 mg of nanoscavenger are used, no organic solvent is required for the extraction and the experiment is performed without the need for filtration or preparation of packed preconcentration columns. 相似文献
59.
H. D. Seltner H. R. Linder B. Schreiber 《International journal of environmental analytical chemistry》2013,93(1):7-12
The mentioned elements are known to occur in the environment in different oxydation states with different biological activities. Speciation of the oxydation state by selective enrichment can lead to relevant information for the toxicologist. -allows to discriminate between the oxidation states of the mentioned elements -converts the elements to the optimum oxydation state for enrichment from the sample -brings the elements in an ideal form for their determination by x-ray fluorescence analysis using coprecipitation with the dibenzyl-ammoniumsalt of dibenzyldithiocarbamic acid. An outline of the method, instrumentation used and applications to organic, biological and environmental samples is given. 相似文献
60.
Sample preparation still remains a great challenge in modern bioanalysis and the interest in new efficient solid phase extraction (SPE) materials still remains high. In this work, hexagonal boron nitride (h-BN) is introduced as a new SPE material for the isolation and enrichment of peptides. The h-BN is isoelectronic and structurally similar to graphite. It has remarkable properties including good thermal conductivity, excellent thermal and chemical stability and a better oxidation resistance than graphite. BN attracts increasing interest because of its wide range of applicability. In the present work, the great potential of h-BN, as a new SPE-material, on the enrichment, preconcentration and desalting of tryptic digest of model proteins is demonstrated. A special attention was dedicated to the efficient enrichment of hydrophilic phosphopeptides. Two elution protocols were developed for the enrichment of peptides compatible for subsequent MALDI-MS and ESI-MS analysis. In addition, the recoveries of 5 peptides and 3 phosphopeptides with wide range of pI values utilizing h-BN materials with different surface areas were investigated. 84–106% recovery rate could be achieved using h-BN materials. The results were compared with those obtained using graphite and silica C18 under the same elution conditions, and lower recoveries were obtained. In addition, h-BN was found to have a capability of protein depletion, which is requisite for the peptide profiling. 相似文献