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《Analytical letters》2012,45(10):2021-2029
ABSTRACT A new adsorbent cinchoine loaded resin (CCR) was prepared with cinchonine loaded on cation exchange resin. ICP-AES was used to study CCR's adsorption properties to Mo(VI) and V(VI). It was found that the adsorption rate was more than 90% in pH (3~6); and 0.6 mol/L HCl could elute Mo and V quantitatively from CCR. The static adsorption capacities are 8.3 mg/g and 9.9 mg/g for Mo and V, respectively. The interference of some ions were also investigated. The proposed method has been applied to determine Mo and V in standard reference samples with s8543172 results. 相似文献
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测定金鸡纳碱的流动注射化学发光新体系 总被引:2,自引:0,他引:2
过氧化氢和高碘酸钠溶液混合能产生弱化学发光,在这一体系中,金鸡纳碱的加入能极大地增强这一化学发光强度,该文对这一化学发光进行了初步的探讨,提出了可能的发光机理,并据此建立了测定金鸡纳碱(奎宁、奎尼丁和辛可宁)的高灵敏度化学发光法;测定奎宁、奎尼丁和辛可宁的线性范围分别为6.0×10-5~1.0×10-2g/L、4.0×10-5~1.0×10-2g/L和1.0×10-3~1.0×10-1g/L,检出限分别为2.1×10-5g/L,1.4×10-5g/L,3.5×10-4g/L;该法适用于奎宁药物的测定. 相似文献
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Photo induced excited state dynamical processes of cinchonine alkaloid dication (C++) have been studied over a wide range of temperature using steady state and nanosecond time-resolved fluorescence spectroscopic
techniques. The temperature-dependent fluorescence studies of C++ clearly indicate the existence of two distinct emitting species having their own characteristic decay rates. The shorter-lived
species shows a usual temperature dependence with increasing non-radiative deactivation at higher temperatures, while the
longer-lived species show features resembling to the excited state solvent relaxation process with a large solvent relaxation
time (τ
r ∼ 6 ns). The species emitting in the lower energy side, having longer decay time is found to be more sensitive towards chloride
ion quenching and has a charge transfer character. Further, concentration quenching with decrease in τ
r of long lived species shows the possibility of energy migration along with solvent relaxation in C++. 相似文献
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A critical examination of the use of the Freundlich isotherm in characterizing molecularly imprinted polymers (MIPs) 总被引:1,自引:0,他引:1
Gregory T. Rushton 《Analytica chimica acta》2005,528(1):107-113
The Freundlich isotherm (FI) has previously been shown to be useful in modeling the binding properties of non-covalent molecularly imprinted polymers (MIPs). The advantage of the FI is that it is a heterogeneous binding model that can accommodate and measure the heterogeneity inherent in MIPs. However, it is often difficult to verify whether the FI is an appropriate binding model for a particular MIP because only a narrow portion of the binding isotherm is experimentally measurable. This study takes a critical examination of whether the FI is an appropriate binding model for MIPs and explores its limitations in characterizing a (+)-cinchonine (CN) imprinted polymer and a non-imprinted polymer (NIP). A wider portion of the binding isotherm can be examined by systematically measuring a series of isotherms at different polymer concentrations. This strategy verified that FI can yield an accurate measure of the heterogeneity in the cinchonine MIP and the NIP. However, in cases of extremely high polymer loading, saturation behavior was observed, and the FI yielded inaccurate measures of the binding properties even though the experimental isotherm appears to be well modeled by the FI. Further, these studies indicate that the FI accurately predicts the heterogeneity index for more homogeneous compared to heterogeneous polymers over a wider concentration range but is subject to considerable error as saturation conditions are approached. These studies demonstrate the importance of correctly applying the FI to the lowest concentration portion of the binding isotherm that is experimentally measurable. 相似文献
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The quaternary ammonium fluoride derived from cinchonine efficiently catalyzed the reaction of 1-phenyl-2-(trimethylsilyl)acetylene with aromatic aldehydes to give the β-branched Morita-Baylis-Hillman-type adducts. 相似文献
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将Ag/AgCl电极于溶胶-凝胶溶液中反复浸3次以上,在室温静置48 h后在1.0×10-2mol.L-1辛可宁溶液中活化至少12 h即制成新型的辛可宁选择性电极。溶胶-凝胶溶液系将正硅酸乙酯、无水乙醇及0.1 mol.L-1盐酸按一定比例混合后加适量的硅钨酸作为活性物质,搅拌30 min混匀后在室温放置24 h配成。辛可宁电极在pH 6.0~7.0,辛可宁浓度在1.0×10-1~1.0×10-5mol.L-1范围内显示Nernst响应,平均斜率为57 mV/pc,检出限为8.0×10-6mol.L-1。 相似文献
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以分子印迹电聚合膜为仿生受体检测辛可宁 总被引:9,自引:0,他引:9
结合分子印迹技术和电聚合自组装技术制备了以辛可宁为模板的印迹聚合膜.膜的厚度可通过改变扫描次数和速度加以控制,因此可在一定程度上克服传统印迹材料固有的传质较慢等缺点.实验中采用铁氰化钾作为探针分子.当模板分子被洗脱后,铁氰化钾小分子可以自由通过聚合膜所形成的识别孔穴,并在电极表面发生氧化还原反应.当识别孔穴捕获辛可宁分子后, 相似文献