亚硝基铁氰化钠分光光度法测定药品“必理通”中对乙酰氨基酚含量

用亚硝基铁氰化钠分光光度法测定药品“必理通”中的对乙酰氨基酚含量。采用亚硝基铁氰化钠试液为显色剂,蒸馏水做溶剂,在波长为700nm下有最大吸收,利用分光光度计测定不同浓度溶液的吸光度,并绘制标准曲线进行分析。实验证明,对乙酰氨基酚在0．024mg／mL～0．168mg／mL浓度范围内,吸光度与样品浓度的线性关系良好,回收率在98．0％以上。此测定方法准确、快速、简便,是测定对乙酰氨基酚含量的最佳方法之一。     

间二氯苯纯度的测定

通过测定间二氯苯中的杂质含量得到间二氯苯的纯度。分别采用高效液相色谱法(HPLC–UVD)和气相色谱法(GC–FID)测定间二氯苯中主要杂质邻、对二氯苯的含量,结果表明两种方法所得杂质含量一致;用高效液相色谱法(HPLC)测定间二氯苯中杂质苯的含量,卡尔费休(Karl Fischer)法测定水分含量,热重法(TGA)进行灰分测定,电感耦合等离子体质谱(ICP–MS)法测定无机杂质含量。最终确定间二氯苯的纯度为99.60%,扩展不确定度为0.03%(k=2)。该方法测定结果准确可靠,具有可溯源性。     

Preparation of a Hybrid Cation-Exchange Monolith and Its Application for the Separation of Proteins by High Performance Liquid Chromatography

A hybrid cation-exchange monolith for high performance liquid chromatography (HPLC) was prepared by a one-pot synthesis with reverse-atom transfer radical polymerization, in which sodium bisulfite was used as the inorganic material, methyl methacrylate was used as organic material, 2, 2'-Azobisisobutyronitrile as initiator, and ferric trichloride as the inorganic catalyst. Moreover, sodium bisulfite was used to provide the sulfonic group. The conditions of polymerization were optimized. The chemical groups of the monolith were assayed by Fourier transform infrared spectroscopy; the morphology of monolithic material was investigated by scanning electron microscopy; the pore size distribution was determined by a mercury porosimeter; and the mechanical stability and permeability of the monolith were investigated by the back-pressure drop at several linear velocities. Finally, the monolith was used to separate human serum albumin from human plasma in conjunction with HPLC in 5 min, and the influences of buffer concentration and pH value on the elution of human serum albumin were investigated. In addition, the monolith was applied to separate lysozyme from egg whites in a short time (4 min) and separate a mixture of aromatic compounds.     

离子色谱法测定沉积物中氯

采用艾斯卡试剂烧结法对沉积物样品进行分解,用离子色谱法分离测定沉积物中氯含量。以IonPacAG11型保护柱和IonPacAS11-HC型分离柱分离,以25mmol.L-1氢氧化钠溶液为淋洗液等度洗脱。方法的检出限(3s)为8μg.g-1。方法用于黄河三角洲沉积物标准物质(GBW 07343,GBW 07344和GBW 07345)的分析,测定值与认定值相一致。     

A Comparative Study of Pigments from the Wall Paintings of Two Greek Byzantine Churches

The goal of this study was to characterize pigments used in the murals of two Byzantine churches, from Kastoria, northern Greece. The identification of the iconographer was also investigated by comparing the pigments applied in the wall paintings of the churches. Pigment microsamples of various colors were collected and analyzed by environmental scanning electron microscopy coupled with an energy dispersive system to characterize the elemental composition. Raman spectroscopy was employed to collect molecular spectra for characterization of mineralogical phases. Hematite, cinnabar, and minium were identified in red surfaces. Brown and yellow colors were assigned to mixtures of iron oxides, iron hydroxides, and calcite. Mixtures of iron, lead, and mercury compounds were used to produce different hues in the murals. Black tones were prepared primarily using charcoal and bone black. Grey colors were produced by a mixture of black carbon with calcite; blue hues, by a mixture of iron oxides, calcite, and black carbon. The minerals used were similar for both churches. However, the green color was prepared either by green earth or mixtures of iron oxides and calcite. A modern pigment, lithopone, was also determined, demonstrating restoration or overpainting and thus complicating possible correlations. Based on these preliminary results, the wall paintings could not be ascribed to a specific iconographer.     

脉冲熔融-飞行时间质谱法测定Ti-Al合金中Ar

本文以标准气体参考物质为依据绘制Ar校准曲线,利用脉冲熔融-飞行时间质谱法建立准确测定钛铝合金中Ar的方法。程序升温法确定钛铝合金中氩可以在分析功率为2800 W时完全释放。并对比了助熔剂和称样量等分析条件对实验结果的影响,结果表明,采用高纯镍篮,钛铝合金中Ar释放完全。本方法测定值与传统脉冲熔融-热导法测定结果基本一致。     

超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯

采用超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯的含量。以四氢呋喃为溶剂对样品进行超声波辅助提取后,加入甲醇对聚合物进行沉淀,取上清液,经冷冻离心后进行气相色谱一质谱分析,并采用氘代邻苯二甲酸酯为内标,单点校正法定量。该方法应用于中、日、韩计量比对的样品测定中,两天进行的6次测定结果相对标准偏差为0．7％～3．0％。最终比对结果显示3个国家的数据取得很好的一致性,除DEP相对标准偏差为2．4％以外,其它5种邻苯二甲酸酯相对标准偏差为0．7％～1．2％,测定结果的相对扩展不确定度为1．8％～4．9％,证明该方法准确、可靠。     

高效液相色谱法测定化妆品中的染料

采用反相高效液相色谱法测定化妆品中对苯二胺等５种染料中间体,以ＺｏｒｂａｘＣ８为固定相,Ｖ（三乙醇胺）∶Ｖ（水）∶Ｖ（乙腈）＝０．９５∶９４．０５∶５为流动相,加入磷酸调ｐＨ值为７．７,检测波长为２８０ｎｍ。样品用体积分数为９５％的乙醇超声提取,回收率为８７％～１０７％（ｎ＝６）,相对标准偏差为２．３％～６．４％。     

Preparation and Characterization of Dichlorocarbene Modified Multiple-walled Carbon Nanotubes

Multiple-walled carbon nanotubes were functionalized by cycloaddition of dichlorocarbene.The chemical modification was performed by using chloroform and sodium hydroxide.Various phase transfer catalysts were used to increase the efficiency of the reaction.Benzyltriethylammonium chloride used as phase transfer catalyst could highly enhance the effect of functionalization.Elemental analysis was used to evaluate the degree of functionalization.Characterization was performed using scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Fourier transform infrared spectroscopy(FTIR)and energy-dispersive X-ray spectroscopy(EDS)were used to confirm the resulting material.     

毛细管气相色谱法测定液化石油气中C_1～C_5组分的方法研究

用毛细管气相色谱法测定液化石油气中C1～C5间13种烃类组分,使用Al2O3大口径毛细管柱,用纯组分混合物作标样,方法快速、灵敏,各组分相对标准偏差为0．39％～5．40％,乙烷、乙烯、丁烷及丁烯异构体得到基线分离。     

气相色谱-质谱联用分析5种有机磷农药时氢气代替氦气作为载气的可行性考察

迄今为止,氦气几乎是气相色谱-质谱联用仪运行中唯一可选的载气.本文使用气相色谱-质谱联用仪考察了氢气和氦气分别作为载气时,对5种有机磷农药混合标准溶液的检测,以确定氢气代替氦气作为气相色谱-质谱联用仪载气用于有机磷农药分析的可行性.用工作站自带解卷积软件(自动质谱解卷积鉴定系统,AMDIS32),结合自建"有机农药质谱库"对结果进行了解析,而后用SPSS统计软件对数据进行了聚类分析.结果发现,以氢气为载气时虽然出峰稍快,但色谱峰分离度较低,解良度较低,且待测物信号不稳定,测定准确度较低,有些化合物甚至检测不到.因此以氢气为载气分析有机磷农药时应对测定准确度、信号稳定性、安全性等诸多因素进行慎重考虑.     

Investigation of the interfacial properties of water-in-diluted-bitumen emulsions using micropipette techniques

The interfacial properties of water-in-diluted bitumen emulsions were studied using micropipette techniques. It was observed that, as bitumen concentration in the bulk phase (C0) increased, the interfacial tension on the water droplet surfaces decreased. In addition, there was a small effect on the interfacial tension when different solvent mixtures were used. Mixtures of toluene and heptane in different ratios were used as solvents for bitumen dilution. Crumpling of the interface was influenced by bitumen concentration and type of solvent. No crumpling was found for bitumen content less than 0.01% for all solvents used. Crumpling was observed at higher bitumen concentrations when deionized water (pH 5.4-5.6) was used. Setting "heptol[A]" to be the mixture of toluene and heptane, with the volume percent of toluene being A, the following were concluded. Crumpling disappeared at C0 > 1% and when heptol[100] was used, and also at C0 > 10% and when heptol[30] was used. Crumpling was strongly affected by the water pH. In the case of heptol[50], at a higher pH, the crumpling region that normally occurred at C0 > 0.01% disappeared. The micropipette technique proved to be useful in studying the interfacial properties of micrometer-sized emulsion drops.     

Analysis of the performance of antibody capture methods using fluorescent peptides with capillary zone electrophoresis with laser-induced fluorescence

A method to analyze the performance of an antibody capture method using fluorescent peptides by capillary zone electrophoresis using laser-induced fluorescence (CZE-LIF) for detection has been developed. Fluorescent peptides from the prion protein were synthesized and the corresponding antibodies were produced in rabbits against these peptides. The antibodies were used to capture the fluorescent peptides. The antibodies were then bound to protein A Sepharose. After elution, the amount of fluorescent peptide that was captured vs. the total amount placed in the assay was evaluated by CZE-LIF. Of the three peptides used in this evaluation, it was found that the recovery was approximately 25-35%. When the abnormal prion protein was prepared from scrapie-infected brain samples from hamsters and a sheep using the previously described extraction method and this method, the amount of abnormal prion protein that was measured in the fluorescence immunoassay correlated with amounts estimated from Western blot. We conclude that this method can be used to detect abnormal prion protein in a tissue sample.     

烟用接装纸质控样品的制备与应用

采用深珠光印字烟用接装纸作为质控样品,用微波消解处理质控样品,以电感耦合等离子体质谱法(ICP–MS)对样品的铬、砷、铅含量进行定值,并进行不确定度评定。利用方差分析评价均匀性,ADF检验评价稳定性。经F检验表明在95%的置信区间,制备的烟用接装纸质控样品均匀性良好;经ADF检验表明,各元素在1%的显著水平下稳定可靠,样品稳定性良好。将烟用接装纸质控样品用于质控,并绘制Levy–Jennings质控图,质控效果良好。     

Degradation of lithium polyphosphate in presence of ethanol

Summary Hydrolytic degradation of lithium polyphosphate catalyzed by ethanol was studied. Two samples with endgroup molecular weights of 4300 and 5500 were used. They were dissolved in 0.1 M NaBf and 30% (v/v) ethanol was used as the catalyst. The hydrolytic degradation of the samples catalyzed by 0.1 M hydrochloric acid was also studied. Kinetic results show that the energies of activation obtained for ethanol-catalyzed reactions were comparable to those obtained for acid-catalyzed reactions. The results are similar to those obtained earlier for water-soluble long-chain sodium polyphosphates and the mechanism of nucleophilic attack is also expected to be the same.     

稀土元素铈对铂铜复合膜电极结构及性能的影响

通过离子束溅射技术分别制备铂铜复合膜电极及掺杂铈元素的铂铜复合膜电极,并在相同条件下对膜电极进行热处理及酸蚀处理。通过高分辨透射电镜、X射线衍射及电化学性能测试对膜电极进行结构及性能的研究。结果表明,在相同后处理条件下,铈元素的添加使铂铜复合膜电极表面出现"桥连"结构,同时促进铂铜元素的合金化程度增强,与纯Pt相比膜电极的析氢交换电流密度提升92.25%。     

离子色谱法测定大肠癌患者尿液中的甘露醇和乳果糖

建立了大肠癌患者尿液中甘露醇和乳果糖的高效阴离子交换分离-脉冲积分安培(HPAEC-PAD)检测方法.样品经稀释、净化、过滤后进行色谱分析,采用Carbopac PA1(250 mm×4mm)阴离子交换柱分离,以NaOH-乙酸钠梯度淋洗液为流动相,流速1.0 mL/min,脉冲积分安培检测器(PAD)检测,外标法定量.结果表明,甘露醇和乳果糖的的线性范围为0.2～20 mg/L,相关系数分别为0.9995和0.9998,回收率为91.7％～102.6％,相对标准偏差均小于2.1％,检出限为0.05和0.06 mg/L(S/N=3).本方法前处理简便、灵敏度高、重现性好,可用于大肠癌患者尿液中的甘露醇和乳果糖的测定.     

Application of a fractionary factorial design to the determination of tin in lubricating oils by continuous flow hydride generation-atomic absorption spectrometry

The determination of wear metals and metalloids in used lubricating oils allows the prediction of equipment failure. A number of procedures to determine wear metals in lubricating oils by atomic spectrometry has been published. Industry has lately shown a special interest in the determination of tin, since its appearance at certain levels in used oils indicates severe engine wear. Therefore, a method for the determination of the total tin content in used lubricating oils by hydride generation-atomic absorption spectrometry (HG-AAS) is described. Unused marine lubricating oils spiked with the analyte were digested in closed vessels in a microwave oven and the diluted product was used for continuous stannane generation. There are many factors that influence effective SnH₄ generation; therefore, fractionary factorial design was used to obtain an adequate sensitivity and also to stabilize the signal. Six variables were taken into account and a 2^6–2 _IV design was used with spiked samples containing 30 ng g^–1 Sn. The reproducibility, stability, calibration curve and limit of detection were established. The method was applied to different kinds of used lubricating oils. In all cases, the results were higher than those obtained in the industry by simple dilution.     

The Effect of Solvent and Fiber Treatment on the Deposition of Organic Silane Solutions Using THF and Acetone

To facilitate the deposition of gamma-ureidopropyltrimethoxysilane monomer onto E-glass fibers, anhydrous acetone and THF were used as carrier solvents. Untreated industrial E-glass fibers and cold water plasma treated E-glass fibers were used. Cold water plasma treatment of the fibers increased the hydrophobicity of the surface by increasing the number of hydroxyl groups at the surface; additionally, the amount of aluminium and calcium at the surface was increased. The silane was found to deposit in bilayers with an external surface due to condensed siloxane; aluminium and calcium were also condensed into the network when acetone was used as a deposition solvent. The bilayers were strongly hydrogen bonded via the ureido functional groups. When THF was used as a carrier solvent, a ureido functional surface was obtained due to the THF interfering with the condensation of the silane. The silane was deposited in conical patches of varying heights. Copyright 2001 Academic Press.