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41.
Evaluation of the wavelength-selective cleavage of five photolabile protecting groups from two different families has been performed. Alanine, as a model bifunctional target molecule was masked at the amino terminal with o-nitrobenzyl group and at the carboxylic terminal with benzyl-type nitrogen and oxygen polyheteroaromatics, namely acridine, (thioxo)benzocoumarin and a coumarin built on the julolidine nucleus. The photosensitivity of the corresponding alanine conjugates was studied at selected wavelengths with HPLC/UV and 1H NMR monitoring. The release of the fully deprotected molecule could be achieved by sequential irradiation in variable irradiation times, which were dependent on the heteroaromatic group used. 相似文献
42.
在稀磷酸介质中 ,二氧化氯 ( Cl O2 )氧化 I- 形成 I3- ,I3- 进一步与吖啶红( ADR)阳离子形成离子缔合物 [ADR][I3]。在聚乙烯醇存在下 ,以试剂空白作参比 ,该离子缔合物的吸收波峰和波谷分别位于 5 82 nm和 5 2 6nm处 ,除波峰和波谷处吸光度与 Cl O2 的浓度有线性关系外 ,波峰和波谷的吸光度绝对值叠加也与 Cl O2 的吸光度呈直线关系。常规方法测定时 ,ε582 =1 .3× 1 0 5L· mol- 1· cm- 1;双波长法测定时 ,ε582 +52 6 =2 .9× 1 0 5L· mol- 1· cm- 1,对 Cl O2 的检出限分别为 0 .8μg/L和 0 .5μg/L。方法已成功地用于自来水中 Cl O2 的测定 相似文献
43.
动力学荧光法测定痕量钒的研究 总被引:5,自引:2,他引:3
基于磷酸介质中,钒(Ⅴ)对溴钾氧化吖啶黄具有催化使用,使体系荧光猝灭,建立了动力学荧光法测定痕量钒的新方法。方法的线性范围为0.02-0.2μg.L^-1和0.2-2.0μg.L^-1,检出限为0.006μg.L^-1。将方法用于水样中钒含量的测定,结果满意,本实验还对反应机理进行了初步探讨。 相似文献
44.
By coupling flow-injection with laser-induced fluorescence detection, a setup was developed and a novel method combining fluorescence resonance energy transfer (FRET) and flow-injection analysis (FIA) was proposed for the determination of vitamin B12 (VB12) based on its fluorescence quenching on the system of acridine orange (AO)/rhodamine 6G (R6G). The effective energy transfer could occur between AO and R6G in the dodecyl benzene sodium sulfonate (DBS) while 454 nm argon laser was used as the excitation source, and as a result, the fluorescence emission of R6G has been increased significantly. It was found that the fluorescence of the above system could be sharply diminished by VB12. By using the mixed solution AO-R6G-DBS and the same solution containing VB12 as the carrier and sample, respectively, a series of negative peaks which could be applied for the quantification of VB12 were obtained. The detection limit for VB12 was 1.65 × 10−6 mol/L. The linear range for determining VB12 was 4 × 10−4 to 2 × 10−6 mol/L (correlation coefficient, r = 0.9923). The method was applied to measure VB12 injections with satisfactory results. 相似文献
45.
《印度化学会志》2021,98(12):100221
Green synthesis of silver nanoparticles was accomplished using peels (rind) extract of Citrus aurantium as a reducing as well as capping agent. Biosynthesized AgNPs (silver nanoparticle) has been characterized via UV–Visible spectroscopy, XRD, SEM, EDAX, TEM and TGA. The observed UV–Vis analysis resulted in the formation of characteristic surface plasmon resonance absorption band centered at 465 nm. The observed XRD patterns, having hkl values (111), (200), (220) and (222), confirms the cubic crystalline structure of AgNPs. The average grain size 9.5 μm was observed by the SEM technique. Bio synthesized AgNPs were efficiently degrading the methylene blue dye nearly 95.35% in 98 h of exposure time. It also degraded acridine orange dye 87.34% and rose bengal dye 90.09% followed by 4h of continuous UV absorption. It also degrades methyl orange dye nearly 51% in 10h of solar irradiation. Synthesized AgNPs can be used as photo-catalyst for degrading toxic dyes. 相似文献
46.
荧光共振能量转移猝灭法测定片剂中莫西沙星含量 总被引:1,自引:0,他引:1
基于在pH 6.50的B-R缓冲溶液,十二烷基硫酸钠(SDS)介质中,吖啶橙(AO)-罗丹明B(RB)能够发生有效的能量转移,使RB荧光增强,而加入莫西沙星(MXFC)后使得RB的荧光猝灭,且其荧光淬灭程度与莫西沙星的质量浓度在1.00~10.0mg.L-1范围内呈线性关系,据此提出了利用AO-RB荧光共振能量转移,荧光淬灭法间接测定片剂中莫西沙星含量的方法。方法的检出限(3S/N)为0.039mg.L-1。方法用于莫西沙星片剂的分析,测定值与高效液相色谱法测定值相一致,加标平均回收率为99%,相对标准偏差(n=5)均小于0.9%。 相似文献
47.
An efficient base-free one-pot synthesis of 1,2-dihydrobenzo[b][1,8]naphthyridines from BH acetates of 2-chloro-3-formylquinolines and activated alkenes followed by their acetylation, with different amines have been reported. These reactions are completed in very short time and provided the products in good to excellent yields. We further explored the scope of BH acetate with carbon nucleophile providing a new route to the synthesis of acridine derivative in excellent yield under mild condition. 相似文献
48.
研究了吖啶橙(AO)与罗丹明B(RB)间发生能量转移的最佳条件,在pH=6.80的Britton-Robinson(B-R)缓冲溶液,十二烷基苯磺酸钠的介质中,AO-RB间发生有效能量转移,使RB荧光大大增强,叶酸(FA)的加入使能量转移体系的RB的荧光强度降低,即发生猝灭.以此建立了利用AO-RB能量转移荧光猝灭法测... 相似文献
49.
Yi Si Feng Jing Jing Ma Xin Yan Lin Jia Song Zhang Peng Lv Hua Jian Xu Lin Bao Luo 《中国化学快报》2012,23(12):1411-1414
Graphene/acridine(G-Acr) hybrid structures were synthesized through covalent functionalization of graphene oxide with 9-(4- aminophenyl)acridine(APA) and its derivatives.The G-Acr hybrids were characterized by Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry,thermal gravimetric analysis and Raman spectroscopy.X-ray photoelectron spectroscopy confirms that the binding energies of APA and its derivatives shifted to higher values,revealing pronounced charge transfer at the interface of graphene and organic molecules. 相似文献
50.