SigmaPlot在化学实验教学中的应用

介绍了SigmaPlot处理实验数据的方法和结果,并与手工作图的结果进行了比较。结果表明,用SigmaPlot对实验数据作线性回归处理,不仅方便快捷,减少数据处理的误差,而且可提高分析结果的准确度。     

利用电子表格自动处理数据高效检定常用玻璃量器

建立利用电子表格自动处理数据高效检定常用玻璃量器的方法。设计电子表格,利用表格处理数据,对常用玻璃量器检定数据自动检索、自动计算以及自动修约。该方法与传统衡量法相比,实现了数据自动计算处理,而且自动修约符合规定,消除了人为计算失误,提高了计算准确率,检定时间比传统方法缩减了约42%,统计学方法表明统计结果具有显著性差异（P<0.01）。该方法不仅成本低,而且提高了检定效率,降低了计算的差错率。     

SigmaPlot软件在化学实验数据处理中的应用

SigmaPlot是功能强大的数据分析和科学绘图软件,通过实例,初步介绍了SigmaPlot处理实验数据的方法和结果。结果表明,用SigmaPlot对实验数据作处理,解决了化学实验中数据多、处理麻烦、手工作图误差大等问题,使处理过程简单、快捷,提高了效率和准确性。     

控制图和最小二乘法处理分析实验数据的介绍

前文曾叙述了少量分析实验数据的统计处理方法,本文拟继续对多量实验数据处理的两种常用方法——控制图法和最小二乘法,作一简要的介绍。控制图控制图是一种将全部测定数据的能变性与任意小组內测定数据的平均能变性进行比较的图示方法。这种方法对于实验数据较多时的处理甚为简便,尤其对     

用高效液相色谱法和模式识别技术定量表征烟叶颜色相似性研究

用高效液相色谱法(HPLC)分析了13种国产烤烟型烟叶中多酚类物质,并定量测定了其中7种主要烟草多酚物质,用模式识别方法处理了HPLC测定多酚的谱图轮廓数据,计算了这些烟叶之间的颜色相似性标度参数TK值,并与人工感官结果进行了比较。结果表明,通过用模式识别技术处理多酚的HPLC轮廓数据,可以定量估计不同产地、不同等级烟叶之间颜色的相似性。模式识别方法处理与感官评价结果基本一致,但前者更客观。因此,模式识别技术可以作为客观评价烟叶颜色质量、弥补人工感官方法的工具。     

数据离群值的检验及处理方法讨论

由目前普遍使用的分析化学教材中与离群值相关的内容出发,对其进行对比和分析,说明数据离群值检验的意义和重要性。对几种常见的离群值判定方法进行了列举和比较,并对已确认为异常值的数据的处理方法也进行了对比和讨论。各种检验和处理方法各有其优势和劣势,根据实际情况选择不同方法或多种方法配合使用,能够更好地实现对离群值的检验和处理。     

Cu—La,Cu—Ce系的热力学

利用推荐的相图及最新发表的热力学实验数据,对Cu—La、Cu—Ce两个二元系进行了优化处理,所得结果与实验数据颇为一致。     

2′-甲基丙烯酰氧基-3α-甲基丙烯酰基胆酸乙酯固化动力学研究

根据文献合成了含有两个双键的胆酸衍生物—2′-甲基丙烯酰氧基-3α-甲基丙烯酰基胆酸乙酯(CAGE2MA),采用非等温DSC法和等温DSC法研究其固化反应。采用Kissinger法处理非等温DSC数据得到动力学数据:Ea=90.16kJ/mol、lnA=21.97和n=0.936。通过积分等转化率法及自催化动力学模型分别处理等温固化DSC数据,前者表明随着反应的进行,Ea和lnA值逐渐减小;后者表明固化温度越高,自催化曲线与实验数据拟合得越好,在高转化率阶段,实验数据与拟合曲线出现偏差。     

反相色谱法测定聚苯乙烯的溶度参数

用反相色谱法测定了聚苯乙烯的溶度参数,实验数据用计算机予以处理,简化了测定过程,建议探针分子与聚合物的极性应尽可能接近。     

谈实验误差

在做化学实验时,常常要用测量方法进行数据的直接测量,或根据实验数据进行推演计算。这些直接测量与推演计算结果的准确性如何？数据如何处理？都会涉及误差问题。     

分段流动分析法测定海水中挥发酚

研究了分段流动分析法测定海水中痕量挥发酚。在实验优化的最佳条件下测定海水中挥发酚,与国家标准方法有良好的相关性。方法的相对标准偏差(RSD)为1.9%,略优于国家标准方法,且操作简便。应用于海水中挥发酚的分析,取得结果满意。     

Comparison study of two procedures for the determination of emamectin benzoate in medicated fish feed

A new method has been developed for the determination of emamectin benzoate in fish feed. The method uses a wet extraction, cleanup by solid-phase extraction, and quantitation and separation by liquid chromatography (LC). In this paper, we compare the performance of this method with that of a previously reported LC assay for the determination of emamectin benzoate in fish feed. Although similar to the previous method, the new procedure uses a different sample pretreatment, wet extraction, and quantitation method. The performance of the new method was compared with that of the previously reported method by analyses of 22 medicated feed samples from various commercial sources. A comparison of the results presented here reveals slightly lower assay values obtained with the new method. Although a paired sample t-test indicates the difference in results is significant, this difference is within the method precision of either procedure.     

Birefringence of highly oriented fibers

A spectrophotometric method was developed for measuring the birefringence of highly oriented synthetic fibers. This method surmounts the low birefringence limit of the standard quartz compensator method and the difficulties in interpretation of the photographic fringe method. A highly oriented aramid fiber gave birefringence values of 0.60–0.75 by this method, compared with 0.25 for polyester and 0.06 for nylon by other conventional methods. The operating principles and excellent results of this new method provide a basis for the extension of routine birefringence characterization to highly oriented fibers.     

Metal-Support Interaction and Catalysis of the Catalysts Prepared Using Microemulsion

We have developed a new preparation method (ME method) of supported metal catalysts by using microemulsion. The metal particles in the catalyst prepared by this method were interacted strongly with support and were considered to be positively charged, and the SiO₂-supported Rh and Fe catalysts prepared by this method exhibited a unique activity and a good selectivity to oxygenates in the hydrogenation of CO. The Al₂O₃-supported Ni catalyst also exhibited an excellent activity and a strong resistance to carbon deposition in the methane-steam reforming. In this review, these interesting catalytic behaviors of the catalysts prepared by ME method were elucidated from the view-point of the electronic state of metals.     

反相高效液相色谱中流动相线性梯度洗脱条件下溶质保留时间预测的新方法

 在计算溶质的梯度保留时间时 ,根据流动相在色谱柱内的分布规律 ,对溶质在色谱柱内的迁移距离和流动相梯度同时进行校正 ,从而建立了一种预测溶质线性梯度洗脱条件下保留时间的新方法。该方法在不同的仪器系统中 ,对于弱保留和强保留溶质在不同线性梯度洗脱条件下保留时间的预测 ,都具有良好的准确度。以 15种氨基酸和 8种苯的同系物为例 ,该方法对于弱保留溶质保留时间的预测 ,相对平均误差分别为 3 70 %和 4 90 % ,远小于文献方法得到的结果 (2 3 6 1%和 31 16 % ) ;对于强保留溶质保留时间的预测 ,相对平均误差分别为 0 2 1%和6 0 1% ,略小于文献 。     

血液乙肝病毒基因检测

全世界每年死于乙型肝炎病毒相关疾病的人数已达60万人,应用荧光定量PCR法检测能够提高乙肝病毒基因的检出率,正确掌握该技术方法能够更加有效地进行疾病诊断和预防工作。基于此,研究针对荧光定量PCR法检测乙肝病毒基因的方法进行探讨。     

全盘自动化气相色谱仪单纯形寻优

自行研制的全盘自动化气相色谱仪在通用计算机的支持下,通过单纯形自动寻优,在色谱专家水平上建立了分析样品的最佳气相色谱分析方法。     

Optimization and performance evaluation of the analysis of glyphosate and AMPA in water by HPLC with fluorescence detection

Summary The object of this work was to optimize and validate an analytical method for the analysis of glyphosate and its main metabolite AMPA (aminomethylphosphonic acid) in natural and drinking water, for sanitary control. The method uses a derivatization step which transforms glyphosate and AMPA into fluorescent products by reaction with 9-fluorenylmethylchloroformate (FMOC-Cl). The kinetics and yield of this reaction were studied by use of different samples. The derivatization products were injected directly into the liquid chromatograph and separated on an amino-functionalized silica gel column. The performance of the method (detection limit, quantification limit, linearity, and relative standard deviation) was studied and the results obtained showed the method was suitable for routine analysis of glyphosate and AMPA. An interlaboratory test with five laboratories confirmed that good results were obtained by use of this method.     

A two‐step method for rapid characterization of electroosmotic flows in capillary electrophoresis

The measurement of electroosmotic flow (EOF) is important in a capillary electrophoresis (CE) experiment in terms of performance optimization and stability improvement. Although several methods exist, there are demanding needs to accurately characterize ultra‐low electroosmotic flow rates (EOF rates), such as in coated capillaries used in protein separations. In this work, a new method, called the two‐step method, was developed to accurately and rapidly measure EOF rates in a capillary, especially for measuring the ultra‐low EOF rates in coated capillaries. In this two‐step method, the EOF rates were calculated by measuring the migration time difference of a neutral marker in two consecutive experiments, in which a pressure driven was introduced to accelerate the migration and the DC voltage was reversed to switch the EOF direction. Uncoated capillaries were first characterized by both this two‐step method and a conventional method to confirm the validity of this new method. Then this new method was applied in the study of coated capillaries. Results show that this new method is not only fast in speed, but also better in accuracy.