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1.
Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chromatography （IC） method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate （anticariogenic agents）, sorbate （a preservative）, and saccharin （an artificial sweetener） in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns, and suppressed conductivity detection. Optimized analytical conditions were further evaluated for accuracy. The relative standard deviations （RSDs） of the inter-day＇s retention time and peak area of all species were less than 0.938% and 8.731%, respectively, while RSDs of 5-day retention time and peak area were less than 1.265% and 8.934%, respectively. The correlation coefficients for targeted analytes ranged from 0.999 7 to 1.000 0. The spiked recoveries for the anions were 90%-102.5%. We concluded that the method can be applied for comprehensive evaluation of commercial gargles. 相似文献
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Determination of fluorinated quinolone antibacterials by ion chromatography with fluorescence detection 总被引：1，自引：0，他引：1
For preparing fluorinated quinolone antibiotic medicine locally used in stomatology, simultaneous determination of norfloxacin, ciprofloxacin, and enoxacin was carried out by multiphase ion chromatography with fluorescence detection. Quinolone antibiotics were separated by Dionex OmniPac PAX-500 column with an eluent of 15 mmol/L H2SO4 and 35% methanol （v/v） at a flow-rate of 1.0 ml/min and detected with fluorescence with excitation and emission wave lengths of 347 ran and 420 ran respectively. The detection limits （S/N=3） of norfloxacin, ciprofloxacin and enoxacin were 50, 105 and 80 ng/ml respectively. The relative standard deviations of retention time, peak area and peak height were less than 1.1% and good linear relationship resulted. The developed method was applied to pharmaceutical formulations and biological fluids. 相似文献
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用乘子法处理多波长吸光度数据,同时测定复方替硝唑含漱液中二组分的含量。简要介绍了乘子法的原理和计算步骤,模拟样品中醋酸氯已定、替硝唑的平均回收率分别为99.75%,100.17%,标准偏差分别为0.73%,0.42%(n=10),对三个批号实际样品的测定结果与标准方法吻合。与标准方法相比,该方法具有简便、快速、易于实现自动分析的优点。 相似文献
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建立超临界流体色谱法分离测定阿咖酚散中阿司匹林、咖啡因和对乙酰氨基酚含量的方法,并研究其影响因素．采用Kromasil Slica填充柱（250mm×4．6mm,5μm）,流动相为含18％甲醇的CO2,流速2．0mL/min,柱温50℃,背压20MPa,检测波长275nm．在测定范围内,对照品浓度与峰面积呈良好的线性关系,以峰面积和保留时间计算精密度分别为阿司匹林0．38％,1．7％,咖啡因0．49％,1．88％和对乙酰氨基酚0．44％,1．09％．5min即可完成测定,且具有较好的重现性和线性关系． 相似文献
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To establish a method for determining five saponins（notoginsenoside R1, ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1 and ammonium glycyrrhizinate） in Glycyrrhizae, Notoginseng and Ginseng, the high performance liquid chromatography with diode array detector（HPLC-DAD） method was applied to an Inertsil ODS-SP column（4.6 mm×250 mm, 5 μm） with a mobile phase consisting of acetonitrile-0.05% phosphoric acid in a gradient elution manner. The flow rate was 1.0 mL/min. The column temperature was 30 ℃ and the detection wavelengths were 203 nm and 237 nm, respectively. The linear ranges were 0.700,0—7.000,0 μg for R1（r=1.000,0）, 0.751,1— 7.511,4 μg for Rg1（r=1.000,0）, 0.677,2—6.771,6 μg for Re（r=1.000,0）, 0.733,9—7.339,1 μg for Rb1（r= 1.000,0）, and 0.540,0—5.399,8 μg for ammonium glycyrrhizinate（r=0.999,9）, respectively. In addition, their average recoveries were 100.28%, 105.83%, 104.09%, 99.36% and 98.54%, respectively. The relative standard deviations（RSDs） of precision, reproducibility and recovery were all less than 1.5%. The results indicate that the method is simple, accurate and reproducible so that it can be used for the simultaneous determination of the five saponins in Chinese patent medicines containing the three kinds of herbs. 相似文献
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利用毛细管电泳法对苹果中阿魏酸和儿茶素做了定性定量分析.通过分离条件的优化,确定了分离苹果中阿魏酸和儿茶素的最佳缓冲液为30 mmol/L硼砂-硼酸+30％乙腈+50 mmol/L SDS,pH=8,这两种酚类物质在10 min内能较好地得到分离.得到儿茶素的峰面积和迁移时间的相对标准偏差(RSD)分别为2.39％和2.92％,阿魏酸的峰面积和迁移时间的RSD分别为3.41％和5.12％;儿茶素的回收率在90％～102％之间,阿魏酸的回收率在87％～105％之间.该方法简单、准确,可作为苹果果实品质测定的一种优良方法. 相似文献
8.
Numerical simulation of TNT underwater explosion was carried out with AUTODYN soft-ware. Influences of artificial viscosity and mesh density on simulation results were discussed. Deto-nation waves in explosive and shock wave in water during early time of explosion are high frequency waves. Fine meshes (less than 1 mm) in explosive and water nearby, and small linear viscosity co-efficients and quadratic viscosity coefficients (0.02 and 0.1 respectively, 1/10 of default values) are needed in numerical simulation model. According to these rules, numerical computing pressure profiles can match well with those calculated by Zamyshlyayev empirical formula. Otherwise peak pressure would be smeared off and upstream relative errors would be cumulated downstream to make downstream peak pressure lower. 相似文献
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Numerical simulation of TNT underwater explosion was carried out with AUTODYN software.Influences of artificial viscosity and mesh density on simulation results were discussed.Detonation waves in explosive and shock wave in water during early time of explosion are high frequency waves.Fine meshes (less than 1 mm) in explosive and water nearby,and small linear viscosity coefficients and quadratic viscosity coefficients (0.02 and 0.1 respectively,1/10 of default values) are needed in numerical simulation model.According to these rules,numerical computing pressure profiles can match well with those calculated by Zamyshlyayev empirical formula.Otherwise peak pressure would be smeared off and upstream relative errors would be cumulated downstream to make downstream peak pressure lower. 相似文献
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将超声波应用于微透析与CE—ICP—AES联用技术,自行设计了超声透析装置,并将该联用技术用于大鼠全血中Mg的形态分析。实验优化条件为：融熔毛细管120cm×100μm（I．D．）;缓冲溶液50mmol·L^-1 Tris—HCI（pH7．4）;电泳电压18KV。在该条件下分析出镁以四种形态存在于大鼠血液透析液中,并通过标准Mg的迁移时间及加标后迁移时间对透析液中游离镁形态进行了表征,峰面积定量透析液中游离镁的含量为24．2mg·L^-1,RSD〈5％,该方法加标回收率为96．0％-103．6％。 相似文献
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通过电沉积的方法将钯纳米颗粒固定到Ag微电极上,制成了钯纳米颗粒修饰Ag微电极,并将此作为毛细管电泳的检测器测定了葡萄糖,探讨了检测电位、分离电位、缓冲溶液的pH值等条件的影响.该方法线性范围为4×10-5～2×10-4 mol/L和2×10-4～1×10-2 mol/L,线性相关系数分别为0.997 0和0.997 5,检出限为1×10-5 mol/L,该微电极表现出良好的稳定性和重现性,迁移时间和峰电流的相对标准偏差分别为2.6%和3.1%（n=8）,分别测定了2个健康人和2个糖尿病患者血清中的葡萄糖,所得结果与医院检测结果一致. 相似文献
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Shu-fang Wang Jing Leng Yi-min Xu Mei-ling Feng 《Journal of Zhejiang University. Science. B》2013,14(7):604-614
Xiongdankaiming tablet (XDKMT), a well-known compound in traditional Chinese medicine, is widely used for the treatment of acute iridocyclitis and primary open-angle glaucoma. In this paper, accurate and reliable methods were developed for the identification of 20 constituents using high-performance liquid chromatography with photodiode array and electron spray ionization-mass spectrometry (HPLC-PDA/ESI-MS n ), and determination of nine of the constituents (chlorogenic acid, gentiopicroside, isochlorogenic acid B, diosmetin-7-O-β-d-glucopyranoside, apigenin, diosmetin, tauroursodeoxycholic acid, acacetin, and taurochenodeoxycholic acid) was developed using HPLC with ultraviolet absorption detector and evaporative light scattering detector (HPLC-UV/ELSD) for the first time. The best results were obtained on a Zorbax SB-C18 column with gradient elution using water (0.1% formic acid) (A) and methanol (0.1% formic acid) (B) at a flow rate of 0.7 ml/min. Tauroursodeoxycholic acid and taurochenodeoxycholic acid, owing to their low UV absorption, were detected by ELSD. The other seven compounds were analyzed by HPLC-UV with variable wavelengths. The calibration curves of all nine constituents showed good linear regression (R 2>0.9996) within the linearity ranges. The limits of detection and quantification were in the ranges of 0.0460–9.90 μg/ml and 0.115–24.8 μg/ml, respectively. The accuracy, in terms of recovery, varied from 95.3% to 104.9% with relative standard deviations (RSDs) less than 4.4%. Precision (with the intra- and inter-day variations less than 4.4%) was also suitable for its intended use. The developed method was successfully applied for the analysis of major components in XDKMT, which provides an appropriate method for the quality control of XDKMT. 相似文献
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The multi-piped freezing method is usually applied in artificial ground freezing (AGF) projects to fulfill special construction requirements, such as two-, three-, or four-piped freezing. Based on potential superposition theory, this paper gives analytical solutions to steady-state frozen temperature for two, three, and four freezing pipes with different temperatures and arranged at random. Specific solutions are derived for some particular arrangements, such as three freezing pipes in a linear arrangement with equal or unequal spacing, right and isosceles triangle arrangements, four freezing pipes in a linear arrangement with equal spacing, and rhombus and rectangle arrangements. A comparison between the analytical solutions and numerical thermal analysis shows that the analytical solutions are sufficiently precise. As a part of the theory of AGF, the analytical solutions of temperature fields for multi-piped freezing with arbitrary layouts and different temperatures of freezing pipes are approached for the first time. 相似文献
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HE Qiang ZHANG Yu-ping XU Jian-bin 《重庆大学学报(英文版)》2005,4(4):208-212
In this paper, the characteristics of integrated biological aerated filter （IBAF） applied to municipal wastewater treatment were studied in a pilot scale experiment. The experimental results showed that IBAF has high efficiencies in removing organic pollutants, such as CODCr and SS, in municipal wastewater. The removal rates of CODCr and SS can reach over 90% and 80%, respectively, when COD and SS in the influent are 234 mg L^-1 and 112 mg L^-1, hydraulic retention time （HRT） is 8 h, and the aerated intensity is in the range of （0.5 to 0.6） L m^-2 s^-1. 相似文献
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Zhao YP Wang XY Wang ZC Lu Y Fu CX Chen SY 《Journal of Zhejiang University. Science. B》2006,7(9):708-712
Objective： To identify compounds that may be responsible for catnip response of Actinidia macrosperma, and compare chemical compositions in the wild and in vitro regenerated plants. Methods： GC-MS and relative retention indices with n-alkanes as reference points were used for compound identification, and component relative percentage was calculated based on GC peak areas without using correction factors. Results： There are 28 compounds （92.72%） and 15 compounds （93.88%） identified in the essential oils from the wild and regenerated plants, respectively. Dihydronepetalactone, iridomyrmecin, and dihydroactinidiolide, which are believed to be attractive to felines, are present in both wild and regenerated plants. Actinine was not detected, and beta-pheylethyl alcohol was only present in wild plant, in addition, short-chain enol derivatives, messengers in chemical communication, are commonly present in wild plant of A. macrosperma, but absent in regenerated one. Conclusion： Dihydronepetalactone, iridomyrmecin, and dihydroactinidiolide are responsible for the catnip response ofA. macrosperma. 相似文献
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电感耦合等离子体发射光谱法在测定铝土矿中SiO_2、Fe_2O_3、TiO_2含量的应用 总被引：1，自引：0，他引：1
使用电感耦合等离子体发射光谱法测定铝土矿中SiO2、Fe2O3、TiO2的含量,通过标准物质拟合工作曲线,一元素多条分析谱线同时测定来校正分析元素谱线间、基体、背景等干扰。测量方法回收率为97.9%～104.9%,相对标准偏差%(n=9)为1.1%～3.7%。方法经国家实物标准物质验证,测定值与标准值基本相符。 相似文献
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应用昆虫生命表技术, 评价了5 个生物制剂对小菜蛾种群的控制作用。结果表明, 013 %印楝素乳油(azadirachtin) 、118 %阿维菌素乳油(abamectin) 与苏云金杆菌乳剂(Bt ) 对小菜蛾种群直接毒杀作用较好,但施用1 次不能将一茬蔬菜上小菜蛾种群趋势指数( I) 降至1100 以下。013 %印楝素乳油+ Bt 乳剂、013 %印楝素乳油+ 118 %阿维菌素乳油, 对小菜蛾的联合控制作用显著, I 值均小于1100 , 同时表明4 个生物制剂对菜田自然天敌无毒副作用。 相似文献
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The mechanism and criterion of crack initiation and propagation of rocks were investigated by many researchers,And the creep behaviour of rocks was also theoretically and experimentally studied by some scientists and engineers.The characteristics of crack initation and propagation of rocks under creep condition.however,are very improtant for rock engineering and still not paid enough attention by researchers,In this paper,the criterion and mechanism of crack initiation and propagation under creep condition were investigated using specimens collected from sandstone rock formations outcropping in the Emei Mountain,the Sichuan Province of China.Cuboid specimens under three point bending were used in this investigation.All specimens were classified into four sorts and used for Mode-I fracutre of creep frcture tests.The experimental result shows that due to creep deformation.rock crack will inevitably initialt and propagate under a load of KI,which is less than fracture toughness KIC but not less than a constant(marked as KIC2),KIC2 indicates the ability of rock to resist crack initiation and propagation under creep conditions and is less than fracture tough ness KIC.defined as creep fracture toughness in this paper,KIC2 should be considered as an importnat parameter on design and computation of rock engineering.The microstructureal mechanism for crack initiation and propagation of rock materials under creep condition was introduced based on competitive model between softening effect and hardening effect,and the validity of test result was explained.The test result was also verified in rheological theory.When KI is more than KIC2 but less than KIC,rock crack will initiate and propagate after a time interval of sustained loading under creep condition.In order to find the relation between duration of sustained lading.which can lead to crack initiation and propagation,and the initial stress intensity factor KI,an unequal0interval time sequence forecasting and predicting model was introduced,and the relation was obtained for homogeneous and isotropic fine-grained red sandstone.Finally a modified fracture toughness formula was given,in which the influence of fracture process zone(FPZ) was fully considered. 相似文献
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Tossapon Wongtangprasert Wirongrong Natakuathung Umaporn Pimpitak Anumart Buakeaw Tanapat Palaga Kittinan Komolpis Nanthika Khongchareonporn 《Journal of Zhejiang University. Science. B》2014,15(2):165-172
A novel monoclonal antibody (MAb) against oxytetracycline (OTC) was generated and characterized. The MAb was used in the development of an enzyme-linked immunosorbant assay (ELISA)-based detection system. An OTC-bovine serum albumin (BSA) conjugate was prepared and used in the immunization of mice. A conventional somatic cell fusion technique was used to generate MAb-secreting hybridomas denoted 2–4F, 7–3G, and 11–11A. An indirect competitive ELISA (icELISA) was applied to measure the sensitivity and specificity of each MAb in terms of its 50% inhibitory concentration (IC50) and percentage of cross-reactivity, respectively. MAb 2–4F exhibited the highest sensitivity, with an IC50 of 7.01 ng/ml. This MAb showed strong cross-reactivity to rolitetracycline, but no cross-reactivity to other unrelated antibiotics. When MAb 2–4F was used to detect OTC from shrimp samples, the recoveries were in the range of 82%–118% for an intra-assay and 96%–113% for an inter-assay. The coefficients of variation of the assays were 3.9%–13.9% and 5.5%–14.9%, respectively. 相似文献