测定司帕沙星的化学发光分析方法

基于在氢氧化钠介质中,司帕沙星对luminol-H2O2化学发光体系有明显的抑制作用,结合流动注射分析技术,建立了流动注射化学发光法测定司帕沙星药物的新方法.在优化的实验条件下,测定司帕沙星的线性范围是1.0×10-7-1.0×10-5mol·L-1,检出限为1.0×10-8mol·L-1,相对标准偏差（1.0×10-7mol·L-1的司帕沙星,n=11）为1.4％.     

司帕沙星氯代物的制备及荧光性质研究

司帕沙星在酸性介质中与亚硝酸反应 ,其重氮盐在氯化亚铜存在下 ,继而与氢氯酸反应生成一种较司帕沙星荧光响应值高 1 1 0倍的强荧光物质 ,采用元素分析、红外光谱和质谱对其衍生物的结构进行了表征。结果表明 ,司帕沙星的荧光强度与其喹啉环 5 位上的氨基密切相关 ,本文还对司帕沙星的荧光自猝灭及氯代荧光增敏机理进行了探讨。     

曙红B荧光猝灭法测定司帕沙星

基于司帕沙星对曙红 B的荧光具有猝灭特性 ,建立一种测定微量司帕沙星的方法。在 p H=3.5的Clark- Lubs缓冲溶液中 ,曙红 B激发波长 λex=30 8nm、发射波长 λem=5 40 nm,司帕沙星的浓度在 0 .2—4 mg· L-1范围内符合比耳定律 ,相关系数为 0 .997,检出限为 0 .0 5 4mg· L-1。该方法对胶囊中的司帕沙星进行回收 ,回收率为 90 %— 10 9% ,相对标准偏差为 1.2 %— 2 .8%。猝灭机理的初步研究 ,认为主要是静态猝灭 ,求得司帕沙星与曙红 B的结合常数为 7.94× 10 4,结合比为 1.0 2。     

光谱学 其他

O657.39 2006031939流动注射化学发光法测定司帕沙星的研究=Chemilumi-nescence determination of Sparfloxacin by flowinjection a-nalysis[刊,中]/石杰(郑州大学化学系.河南,郑州(450052)) ,曹丰璞…∥分析试验室.—2006 ,25(3) .—89-91采用流动注射技术,建立了一种简单、快速测定司帕沙星的方法。线性范围为1 .0×10-7~8 .5×10-4mol/L,检出限为6 .5×10-8mol/L。利用该法测定了司帕沙星片剂中的司帕沙星,回收率在98 .8 %~104 .4 %之间。图1表2参12(严寒)O657.39 2006031940流动注射化学发光法测定褪黑素=Determination of me-laton…     

荧光法研究司帕沙星与白蛋白的作用

本文用荧光光谱法、分光光度法研究了水溶液中喹诺酮类药物司帕沙星与牛血清白蛋白 (BSA)、鸡蛋白 (CEA)的相互作用 ,求得它们间的结合常数为K鸡 =8 2 9× 10 6,K牛 =4 41× 10 7;结合位点数分别为n鸡=0 5 88,n牛 =0 793,并根据F rster非辐射能量转移机制 ,测定了司帕沙星与两种血清白蛋白相互结合时其给体 受体间距离 (R鸡 =1 99nm ,R牛 =2 0 9nm)和能量转移效率 (E鸡 =0 76 6 ,E牛 =0 714)。实验表明 ,随着温度升高 ,BSA及CEA的猝灭曲线斜率降低 ,证实了司帕沙星与BSA和CEA的相互结合作用为单一的静态猝灭过程 ,其作用机制属能量转移机制。通过两种血清白蛋白与抗菌药物司帕沙星结合反应 ,探讨了药物司帕沙星在生物体内与蛋白质的相互作用的生物学效应及其作用机理。     

八元瓜环与氧氟沙星、氟罗沙星、加替沙星及司帕沙星相互作用的光谱法研究

用荧光光谱和紫外吸收光谱研究了八元瓜环与氧氟沙星、氟罗沙星、加替沙星及司帕沙星的相互作用体系的性质,考察了溶液酸度对作用体系的影响。在pH小于8.0的范围内,八元瓜环分别与氧氟沙星、氟罗沙星、加替沙星形成1∶1、与司帕沙星形成2∶1的稳定的主客体化合物;测定了不同pH时主客体相互作用的稳定常数均在103～104 L·mol-1(司帕沙星体系为1011 L2·mol-2)范围;同时测定了各作用体系的荧光发射和紫外吸收分析性能参数,药物客体的浓度线性范围达2～3个数量级,检测限为10-9～10-8 mol·L-1。     

司帕沙星与对硝基酚荷移反应的研究

本文主要研究在水溶液中 ,司帕沙星与对硝基酚发生反应 ,生成稳定的 1∶ 1的络合物 ,其最大吸收波长为 397.0 nm,线性范围 0 .9— 30 μg/ m L。表观摩尔吸光系数 ε=4 .0 7× 10 4 L·mol-1·cm-1,基于以上反应建立本方法 ,用于测定药物制剂中的司帕沙星含量与文献方法一致 ,回收率为 99.60 %— 10 0 %,相对标准偏差为 1.93%。     

水溶性量子点荧光探针用于帕珠沙星的含量测定

文章采用荧光光谱和紫外光谱研究了CdTe量子点(CdTe QDs)与广谱抗菌药物帕珠沙星的相互作用。结果表明,随着帕珠沙星浓度的增加,CdTe QDs荧光强度有规律的降低,但通过透射电镜图对QDs及加入帕珠沙星后的QDs进行比较,发现QDs仍然均一单分散,表明反应的作用机理可能是帕珠沙星促使QDs表面键合的有机分子发生变化,在Cd空位表现出的表面缺损上形成了碲氧复合物,致使荧光猝灭。因此该反应可作为一种新颖的快速检测帕珠沙星含量的方法。在一定条件下,帕珠沙星溶液的浓度与量子点荧光强度成线性关系,线性范围为10.0～850 μg·mL-1,相关系数r为0.995 4,检测限(S/N=3)为3.254×10-3 μg·mL-1。药物对量子点的猝灭常数为2.188×104 L·mol-1。应用到冻干粉针剂和氯化钠注射液中帕珠沙星的含量测定,所得结果与标示量一致。该方法较常用检测方法具有简便、快捷、灵敏、线性范围宽的优点,并有望进一步开展发药物体内显像及作用机理的研究。     

甲磺酸帕珠沙星荧光光谱特性研究及应用

研究了低浓度甲磺酸帕珠沙星水溶液的最佳激发波长,荧光光谱和同步共振光谱,不同实验条件对其荧光强度的影响。结果显示,甲磺酸帕珠沙星溶液在407nm出现明显的荧光峰,在375nm出现共振荧光峰,最佳激发波长为285nm。随浓度增加,407nm处的荧光强度线性增强,当浓度增至6×10~(-4)mol/L后,发生荧光猝灭,荧光强度线性减弱。不同的表面活性剂对甲磺酸帕珠沙星水溶液荧光强度有增强或猝灭作用。在pH为9.18硼砂的缓冲溶液中,甲磺酸帕珠沙星水溶液荧光强度最强。利用其荧光光谱特性,测定样品中甲磺酸帕珠沙星,结果满意。     

紫外分光光度法测定甲磺酸帕珠沙星原料药含量

采用紫外分光光度法测定了甲磺酸帕珠沙星原料药的含量,并与高效液相色谱法和酸碱滴定法的测定结果进行了比较.该法简便、快速、结果准确.为甲磺酸帕珠沙星在生产过程中的质量控制提供了可靠依据.     

Improvement of Structural,Rheological, and physicochemical properties of type I collagen by calcium lactate combined with ultrasound

Type I collagen has a relatively stable quality while quite resistant to digestion because of the complex triple helix structure. This study was conducted to explore the acoustic conditions of ultrasound (UD)-assisted calcium lactate processing of collagen and control the processing process through its sono-physico-chemical effects. The findings demonstrated that UD might lower the average particle size of collagen and increase its zeta potential. In contrast, the rise in calcium lactate concentration could dramatically limit the impact of UD processing. This may be because of its low acoustic cavitation effect, as demonstrated by the phthalic acid method (the fluorescence value decreased from 81245.67 to 18243.67). Poor changes in tertiary and secondary structures confirmed the detrimental effect of calcium lactate concentration on UD-assisted processing. Although UD-assisted calcium lactate processing can significantly alter the structure of collagen, the integrity of the collagen is basically preserved. Furthermore, the addition of UD and a trace amount of calcium lactate (0.1%) increased the roughness of the fiber structure. At this relatively low calcium lactate concentration, ultrasound improved the gastric digestibility of collagen by nearly 20%.     

Correlation between proton magnetic resonance spectroscopic lactate measurements and vascular reactivity in chronic occlusive cerebrovascular disease: a comparison with positron emission tomography

The purpose of this study is to investigate the correlation between lactate levels and cerebral vascular reactivity (VR) in regions outside an area of chronic cerebral infarction. Multivoxel proton magnetic resonance spectroscopy ((1)H-MRS) and positron emission tomography (PET) were performed in 11 patients who suffered chronic cerebral infarction. Of these 11 patients, 4 were examined before and after bypass surgery. Two regions-of-interests (ROIs) were placed outside the area of chronic infarction. One ROI was placed within a control region on the contralateral side. A lactate peak area was obtained in all ROIs. An N-acetyl aspartate (NAA) peak area was obtained in the ROI within the control region. The ratio of the lactate peak area and NAA peak area (Lct/NAA) was calculated for normalization of the lactate level, and was found to be 0.13 +/- 0. 10 (range, 0 to 0.43). The VR was recorded at 13.3 +/- 20.7% (range, - 44.3 to 68.9%), utilizing PET and administering acetazolamide. A significant negative correlation was observed between the Lct/NAA ratio and VR (r = - 0.709, p < 0.0001). These results suggest that lactate levels and VR are closely related in regions outside areas of chronic cerebral infarction.     

Quantitative evaluation of the lactate signal loss and its spatial dependence in press localized (1)H NMR spectroscopy

Localized (1)H NMR spectroscopy using the 90 degrees -t(1)-180 degrees -t(1)+t(2)-180 degrees -t(2)-Acq. PRESS sequence can lead to a signal loss for the lactate doublet compared with signals from uncoupled nuclei which is dependent on the choice of t(1) and t(2). The most striking signal loss of up to 78% of the total signal occurs with the symmetrical PRESS sequence (t(1)=t(2)) at an echo time of 2/J (approximately 290 ms). Calculations have shown that this signal loss is related to the pulse angle distributions produced by the two refocusing pulses which leads to the creation of single quantum polarization transfer (PT) as well as to not directly observable states (NDOS) of the lactate AX(3) spin system: zero- and multiple-quantum coherences, and longitudinal spin orders. In addition, the chemical shift dependent voxel displacement (VOD) leads to further signal loss. By calculating the density operator for various of the echo times TE=n/J, n=1, 2, 3,..., we calculated quantitatively the contributions of these effects to the signal loss as well as their spatial distribution. A maximum signal loss of 75% can be expected from theory for the symmetrical PRESS sequence and TE=2/J for Hamming filtered sinc pulses, whereby 47% are due to the creation of NDOS and up to 28% arise from PT. Taking also the VOD effect into account (2 mT/m slice selection gradients, 20-mm slices) leads to 54% signal loss from NDOS and up to 24% from PT, leading to a maximum signal loss of 78%. Using RE-BURP pulses with their more rectangular pulse angle distributions reduces the maximum signal loss to 44%. Experiments at 1.5 T using a lactate solution demonstrated a maximum lactate signal loss for sinc pulses of 82% (52% NDOS, 30% PT) at TE=290 ms using the symmetrical PRESS sequence. The great signal loss and its spatial distribution is of importance for investigations using a symmetrical PRESS sequence at TE=2/J.     

烟酸诺氟沙星和乳酸诺氟沙星的荧光特性及应用

研究了烟酸诺氟沙星和乳酸诺氟沙星在不同介质中的荧光特性。采用荧光分光光度法测定了烟酸诺氟沙星和乳酸诺氟沙星的含量。烟酸诺氟沙星和乳酸诺氟沙星分别在0.025—2.5μg/mL和0.01—2μg/mL范围内,其荧光强度与浓度线性关系良好。     

Optimization and kinetic modeling of ultrasonic-assisted extraction of fucoxanthin from edible brown algae Sargassum fusiforme using green solvents

The development of green and sustainable extraction technologies for various naturally active biomaterials is gaining increasing attention due to their environmentally friendly advantages. In this work, the ultrasonic-assisted extraction of fucoxanthin from edible brown algae Sargassum fusiforme using different green solvents was presented. Ethyl lactate, limonene, soybean oil, and sunflower oil were used in place of traditional organic solvents. Ethyl lactate showed similar performance to organic solvents, whereas limonene and vegetable oil exhibited higher selectivity for fucoxanthin. Moreover, the effects of various extraction factors, including liquid/solid ratio, extraction time, extraction temperature, as well as amplitude were studied. The optimal conditions were optimized as follows: liquid/solid ratio, 40 mL/g; extraction time, 27 min; extraction temperature, 75 ℃; amplitude, 53%; and solvent, ethyl lactate. Optimal model of second-order kinetic parameters (rate constant, equilibrium concentration, and initial extraction rate) was successfully developed for describing the dynamic ultrasonic extraction process under different operating conditions.     

Feasibility of using hyperpolarized [1-13C]lactate as a substrate for in vivo metabolic 13C MRSI studies

The development of dynamic nuclear polarization in solution has enabled in vivo 13C MR studies at high signal-to-noise ratio following injection of prepolarized 13C substrates. While prior studies have demonstrated the ability to observe metabolism following injection of hyperpolarized 13C pyruvate, the goal of this study was to develop and test a new hyperpolarized agent for investigating in vivo metabolism, [1-13C]lactate. A preparation for prepolarized 13C lactate and the requisite dissolution media were developed to investigate the feasibility for in vivo 13C MRS/MRSI studies following injection of this hyperpolarized agent. This study demonstrated, for the first time, not only the ability to detect hyperpolarized [1-13C]lactate in vivo but also the metabolic products 13C pyruvate, 13C alanine and 13C bicarbonate following injection in normal rats. The use of 13C lactate as a substrate provided the opportunity to study the conversion of lactate to pyruvate in vivo and to detect the secondary conversions to alanine and bicarbonate through pyruvate. This study also demonstrated the potential value of this hyperpolarized agent to investigate in vivo lactate uptake and metabolism in preclinical animal models.     

Effect of Nanoclay along with Other Effective Parameters on Gelation Time of Hydro Polymer Gels

In this work, a hydrogel was prepared by crosslinking of aqueous solutions of sulfonated polyacrylamide/chromium triacetate for the purpose of water shut-off treatment in oil fields. In order to screen the factors that affect the gelation time and investigate their interactions, a 32 run fractional factorial design was used in experimentation with eight factors (pH, CaCl₂ concentration, crosslinker/copolymer ratio, NaCl concentration, copolymer concentration and presence or absence of sodium lactate, nanoclay, and thiouria) and one response (gelation time). Furthermore, the analysis of variance (ANOVA) was implemented as a significant tool to evaluate the quality of the quadratic model. The ANOVA results of the developed model showed it was significant with a 99% confidence limit. Among the eight factors, presence of sodium lactate, copolymer concentration, presence of nanoclay, presence of thiouria, and crosslinker/copolymer ratio had, in order, the main effects, and the interactions between sodium lactate and crosslinker/copolymer ratio and between pH and crosslinker/copolymer ratio were highly significant.     

Semiconductor–Metal Transition in Magnetic Semiconductor Compounds at High Pressure

Journal of Experimental and Theoretical Physics - The magnetic, transport, and magnetotransport properties of ferromagnetic Zn0.1Cd0.9GeAs2 + 10% MnAs and Zn0.1Cd0.9GeAs2 + 15% MnAs nanocomposites...     

Detection of intracellular lactate with localized diffusion {1H-13C}-spectroscopy in rat glioma in vivo

The aim of this study was to compare the diffusion characteristic of lactate and alanine in a brain tumor model to that of normal brain metabolites known to be mainly intracellular such as N-acetylaspartate or creatine. The diffusion of (13)C-labeled metabolites was measured in vivo with localized NMR spectroscopy at 9.4 T (400 MHz) using a previously described localization and editing pulse sequence known as ACED-STEAM ('adiabatic carbon editing and decoupling'). (13)C-labeled glucose was administered and the apparent diffusion coefficients of the glycolytic products, {(1)H-(13)C}-lactate and {(1)H-(13)C}-alanine, were determined in rat intracerebral 9L glioma. To obtain insights into {(1)H-(13)C}-lactate compartmentation (intra- versus extracellular), the pulse sequence used very large diffusion weighting (50 ms/microm(2)). Multi-exponential diffusion attenuation of the lactate metabolite signals was observed. The persistence of a lactate signal at very large diffusion weighting provided direct experimental evidence of significant intracellular lactate concentration. To investigate the spatial distribution of lactate and other metabolites, (1)H spectroscopic images were also acquired. Lactate and choline-containing compounds were consistently elevated in tumor tissue, but not in necrotic regions and surrounding normal-appearing brain. Overall, these findings suggest that lactate is mainly associated with tumor tissue and that within the time-frame of these experiments at least some of the glycolytic product ([(13)C] lactate) originates from an intracellular compartment.     

光电直读光谱仪同时测定金属铝中15个元素

本文研究了用光电直读光谱法同时测定金属铝中１５个元素的方法,对光源及测定条件进行了最佳选择,具有测定时间短,灵敏度、准确度高等优点。含量在０．１－１％之间,ＲＳＤ〈３％含量在０．００１－０．１％之间,ＲＳＤ〈６％;含量〈０．００１％,ＲＳＤ〈１４％,经与化学法比对,结果十分吻合。