分辨伏安分析重叠峰的研究

研究了一种处理伏安(极谱)重叠峰的数学模型。将几类具峰状的极谱电流公式归纳成一般的关系式,提出了一个通用的拟合函数,经非线性最小二乘法处理,可得到重叠组份的蜂高、峰电位和半峰宽等参数。本法适用于示差脉冲极谱、交流极谱、方波极谱、一阶导数卷积伏安法及其反向溶出伏安重叠峰的分离。已用于示差脉冲极谱和交流极谱重叠峰的分辨,得到满意结果。     

谱峰漂移校正技术结合三维平行因子分析方法用于分辨中药重叠高效液相色谱信号

谱峰漂移校正技术结合平行因子分析方法被应用于中药色谱重叠峰信号分辨. 谱峰漂移校正技术的使用, 使得数据的三线性得以加强, 更适合于平行因子分析方法的分辨. 本文通过对中药延胡索色谱数据分辨, 并与经典多元曲线分辨方法对比来验证谱峰漂移校正技术结合平行因子分析方法的正确性.     

样条小波变换用于分辨重叠伏安峰的研究

将样条小波变换技术用于分辨重叠的伏安峰 ,以选定的分辨因子作用于样条小波滤波器 ,使之成为峰分辨器 ,用它来直接处理重叠的伏安峰 ,取得了较好的结果 .被处理峰可达到基线分离 ,且峰位置的相对误差小于 3.0 %,峰面积的相对误差小于 5 .0 %,方法简便易行 .讨论了各种影响分峰效果的因素 ,包括不同的分辨因子及样条小波基等 ,并应用于镉 (Ⅱ ) 铟 (Ⅲ )和铅 (Ⅱ ) 铊 (Ⅰ )体系的实验数据的处理以验证该方法     

锌(Ⅱ)-邻菲罗啉络合物的极谱行为及应用

在0.075 mol.L-1硼酸-氢氧化钠的缓冲溶液中(pH 8.9),锌(Ⅱ)与邻菲罗形成的络合物是电活性的,于-1.30 V(vs.SCE)产生较灵敏的极谱峰,峰电流与锌(Ⅱ)浓度在4.0×10-8~2.0×10-6mol.L-1之间存在线性关系(r=0.998 6),检出限为2.0×10-8mol.L-1。利用线性扫描极谱法探讨了极谱峰的电化学性质及电极反应机理,并将该法成功应用于测定葡萄糖酸锌口服液中锌的含量。     

硫离子的脉冲极谱

硫离子的极谱性能和测定已有不少报导。本文研究了硫离子在碱性硼酸钠缓冲溶液中的导数脉冲极谱行为。借正向线性扫描(本文系由负向正)附加负脉冲的方法使记录出的脉冲极谱峰具有阴极溶出峰的特点(延迟时间时就地富集,极化脉冲时溶出),称为“就地阴极溶出法”。硫离子就地阴极溶出峰比其阳极氧化峰的灵敏度提高2—7倍,可测定硫离子浓度达1×10~(-7)M。此外,能同时获得分辨良好的硫离子和氰离子的阳极导数脉冲极谱峰,提供了对这两种离子同时测定的可能性。借导数脉冲极谱峰电位计算了硫氢酸的解离常数和HgS的溶度积。硫离子阴极溶出脉冲极谱法灵敏度更高,可测至10~(-8)M。     

Kalman滤波技术校正电感耦合等离子体原子发射光谱分析中严重重叠的谱线干扰

针对ICP-AES中严重重叠谱线干扰的校正,研究了若干因素对Kalman滤波器性能的影响.减小扫描步长可以增强Kalman滤波法解析重叠谱线的能力.当重叠线对轮廓基本相同且扫描窗口内干扰元素只有一条谱线时,Kalman滤波法能分辨的重叠线对的最小峰间距为扫描步长的2～3倍.扫描窗口内较多的干扰元素谱线和重叠线对轮廓的显著差异有利于Kalman滤波器正确识别分析信号和干扰信号,可以利用这两个因素有效地分辨峰间距很小甚至完全重叠的谱线.     

基于分形理论分辨重叠峰的新算法

将分形理论用于仪器分析信号的解析,提出一种面向分析谱图中重叠信号处理的分形分辨算法.通过对信号进行分形分析,采用分形维数可有效地反映信号的特征,准确地得到谱峰个数和位置的信息,避免人为判断的误差,实现重叠复合信号的分辨.实验表明,这种新的重叠谱峰分辨法能用于光谱、电化学、色谱等仪器分析数据的处理     

铜(Ⅱ)与芳基取代酰基吡唑啉酮、腺嘌呤三元配合物吸附波的研究

在Hac-NaAc缓冲溶液中(pH 5.0),用单扫示波极谱法得到1-对氯苯基-3-呋喃基-4-呋喃甲酰基-5-吡唑啉酮(HL)、腺嘌呤(Ade)与铜(Ⅱ)三元配合物的灵敏吸附波,其峰电位为-0.58 V(vs.SEC).峰电流与铜质量浓度在0.02～10mg/L范围内分段呈线性关系,定量下限为2μg/L(3×10-8mol/L).采用多种电化学方法研究了极谱波的性质和电极反应机理.峰电流由中心离子铜(Ⅱ)还原产生.用直线法测得多元配合物组成比为1:1:1,表观稳定常数为7×107.此方法已用于粗盐、麦片和化妆品中痕量铜的测定,标准回收率98%～103%.     

直观推导式演进特征投影法解析多环芳烃的重叠色谱峰

用高效液相色谱法(HPLC)测定多环芳烃时,因芴、苊和菲,茚(1,2,3-cd)芘和苯并(g,h,i)苝的色谱峰严重重叠而影响测定结果。本研究用高效液相色谱-二极管阵列检测器(DAD)和荧光检测器(FLD)测定多环芳烃,在激发波长λex=230nm,发射波长λem=300～500nm范围内采集重叠峰的HPLC-FLD二维色谱数据,再用直观推导式演进特征投影法(HELP)解析它们的重叠色谱峰,分辨结果令人满意。该方法对重叠组分的分辨下限为0.02mg/L。结果表明,用二维色谱荧光数据解析色谱重叠峰,灵敏度更高,可用于环境样品中多环芳烃的测定。     

Kalman滤波技术校正电感耦合等离子体原子发射光谱分析中严重重叠的谱线干扰

针对ICP-AES中严重重叠谱线干扰的校正, 研究了若干因素对Kalman滤波器性能的影响。减小扫描步长可以增强Kalman滤波法解析重叠谱线的能力。当重叠线轮廓基本相同且扫描窗口内干扰元素只有一条谱线时, Kalman滤波法能分辨的重叠线对的最小峰间距为扫描步长的2～3倍。扫描窗口内较多的干扰元素谱线和重叠线对轮廓的显著差异有利于Kalman滤波器正确识别分析信号和干扰信号, 可以利用这两个因素有效地分辨峰间距很小甚至完全重叠的谱线。     

Identification of Leguminosae gums and evaluation of carob-guar mixtures by capillary zone electrophoresis of protein extracts

A procedure for the extraction and capillary zone electrophoresis (CZE) separation of proteins from carob, guar and tara gums in a background electrolyte (BGE) of pH 9 containing 0.1% polyvinyl alcohol is described. The CZE protein profiles exhibit characteristic peaks for each one of the Leguminosae gums, which can be used to construct models capable of identifying samples of carob, guar and tara gums, and predicting the guar content in binary carob-guar mixtures of different geographical origin and harvested in different years. The classification and prediction models are constructed by using linear discriminant analysis (LDA) and multiple linear regression (MLR), respectively. An excellent resolution between the three categories is obtained with LDA, the model being capable of classifying samples with recognition and prediction capabilities of 100%. For MLR models constructed with carob-guar mixtures with and without a common history, the average of the calibration residuals are +/- 0.50 and +/- 0.90%, respectively (average values for the 2-20% guar range). For the later model, the detection limit was 3.2% guar (from the standard deviation of 18 mixtures with 2-4% guar, and for alpha = beta = 0.05).     

高效液相色谱法测定尿液中的异硫氰酸酯

 省去合成1,3 苯二硫杂环五烯 2 硫酮这一步骤，直接用异硫氰酸丙基酯与1,2 苯二硫酚反应作标准，建立了尿液中异硫氰酸酯的反相高效液相色谱(HPLC)测定方法。异硫氰酸丙基酯的标准曲线回归方程 y =0.418 2x + 2.821 ( r2 = 0.999 3 )与异硫氰酸甲基酯的回归方程 y = 0.412 2x + 2.442 3 ( r 2= 0.996 6 )基本拟合。检出限(以信噪比为2.5计)为0.08 μ mol/L 。日内重现性( n =21)以相对标准偏差(RSD)表     

醇类化合物气相色谱保留指数的分子拓扑研究

分子中原子i的特征值(ti)定义为tj＝1 ∑hi。并计算了醇类化合物的氢连接性指数，藉助多元线性回归技术分别建立了25个醇类化合物的指数与这些物质的气相色谱保留指数的定量结构／性质相关关系模型。模型具有良好的稳定性和预测能力，氢连接性指数能较好地反映化合物的结构特征。     

Development and validation of a high-performance thin-layer chromatographic method, with densitometry, for quantitative analysis of ketorolac tromethamine in human plasma

Ketorolac tromethamine is a potent nonsteroidal anti-inflammatory drug that is widely used in the treatment of moderate to severe pain. A new method was developed and validated for quantifying ketorolac (the free acid of the tromethamine salt) in human plasma by high-performance thin-layer chromatography. The stationary phase was silica gel 60, and the composition of the mobile phase was n-butanol-chloroform-acetic acid-ammonium hydroxide-water (9 + 3 + 5 + 1 + 2, v/v). The densitometric analysis of ketorolac was performed at 323 nm. The method was validated for precision (repeatability and reproducibility), accuracy, and sensitivity. Repeatability was 10.11% [coefficient of variation (CV)] and reproducibility was 12.18% (CV) as the maximum variation. Accuracy was determined at 3 different concentration levels, and results were within +/-15% of the predetermined range. Data were fitted by a linear mathematical function (linear regression). The calibration graph was linear in the range of 200-2000 ng/mL. Average recovery was 73.67%. The method proved to be accurate, precise, and sensitive for the ketorolac tromethamine quantification.     

Study of Cd2+ complexation by the glutathione fragments Cys-Gly (CG) and gamma-Glu-Cys (gamma-EC) by differential pulse polarography

A differential pulse polarographic study of the Cd2+/gamma-Glu-Cys and Cd2+/Cys-Gly systems assisted by the alternating least-squares multivariate curve resolution (MCR-ALS) method was carried out to obtain a better understanding of the different metal affinities of the complexation sites on glutathione (GSH). The simultaneous analysis of the titration of peptide with metal and of metal with peptide allowed the resolution of the Cd2+/Cys-Gly system, whereas in the analysis of the Cd2+/gamma-Glu-Cys system the analysis of a single titration experiment was sufficient. The analysis of the shape of the resulting pure voltammograms and concentration profiles of the resolved components suggested the presence of two different types of bound Cd2+ in the two systems considered, that could be attributed to Cd2+ bound to one or two sulfur atoms to form complexes of stoichiometry 1:1 and 1:2. respectively.     

支持向量机分类和回归用于肽的QSAR研究

使用支持向量机技术对两类肽化合物体系进行了分类和回归研究,并将其系统地与K最邻近法、多元线性回归、偏最小二乘、人工神经网络进行了比较。结果表明,对于小样本、非线性问题,支持向量机具有较强的稳定性能及泛化能力,在大多数情况下能够得到优于传统方法的建模效果。对于分类问题,支持向量机对训练集和测试集都达到了100%的分类正确率;对于回归问题,支持向量机虽对训练集样本拟合效果略低于人工神经网络,但对外部测试集却表现出较强的预测能力。     

Vibrational distributions of the CO(v) products of the C2H2 + O(3P) and HCCO + O(3P) reactions studied by FTIR emission

The C2H2 + O(3P) and HCCO + O(3P) reactions are investigated using Fourier transform infrared (FTIR) emission spectroscopy. The O(3P) radicals are produced by 193 nm photolysis of an SO2 precursor or microwave discharge in O2. The HCCO radical is either formed in the first step of the C2H2 + O(3P) reaction or by 193 nm photodissociation of ethyl ethynyl ether. Vibrationally excited CO and CO2 products are observed. The microwave discharge experiment [C2H2 + O(3P)] shows a bimodal distribution of the CO(v) product, which is due to the sequential C2H2 + O(3P) and HCCO + O(3P) reactions. The vibrational distribution of CO(v) from the HCCO + O(3P) reaction also shows its own bimodal shape. The vibrational distribution of CO(v) from C2H2 + O(3P) can be characterized by a Boltzmann plot with a vibrational temperature of approximately 2400 +/- 100 K, in agreement with previous results. The CO distribution from the HCCO + O(3P) reaction, when studied under conditions to minimize other processes, shows very little contamination from other reactions, and the distribution can be characterized by a linear combination of Boltzmann plots with two vibrational temperatures: 2320 +/- 40 and 10 300 +/- 600 K. From the experimental results and previous theoretical work, the bimodal CO(v) distribution for the HCCO + O(3P) reaction suggests a sequential dissociation process of the HC(O)CO++ --> CO + HCO; HCO --> H + CO.     

混合氯化石蜡中短链氯化石蜡定量分析方法的比较

分别采用总体响应因子校正法和多元线性回归法对混合氯化石蜡中短链氯化石蜡进行定量分析,结果表明:两种方法均能较好地排除中链氯化石蜡的干扰,从而提高了短链氯化石蜡的定量准确性;但是两种方法均对标准曲线的浓度范围存在一定的依赖性,在使用这两种方法进行定量分析时,应将样品稀释到标准曲线适用的浓度范围。另外,相对于总体响应因子校正法,多元线性回归法定量范围更广。