A Two Factor Simplex Optimization of An Ion Pair Liquid Chromatographic Separation

Abstract

A simple two factor simplex is used to optimize the separation of several ionic naphthylamines by varying the pH and percent methanol in the eluting solvent.     

一种新改进单纯形优化方法

本文采用模糊数学方法计算了多指标综合评价值,并以它作为单纯形优化的目标函数,建立了一种新改进单纯形优化方法,改进了反射基点、形心点和反射系数的计算方法。     

Characterization of Pd Blacks by Temperature Programmed Oxidation

Using different reduction conditions Pd powders have been prepared and characterized by chemisorption and TPO (Temperature Programmed Oxidation) measurements. The amount of carbon deposits introduced during preparation seems to be peculiar to the preparation procedure. The O₂ consumption curves attributed to PdO formation have shown two peak minima suggesting strong differences in the accessibility of Pd particles.     

用模糊综合评价值作为单纯形优化指标

本文介绍了一个模糊综合评价方法,讨论了模糊运算方法对运算结果即综合评价值的影响,并将模糊综合评价值用作单纯形优化指标。     

A Novel Quality Criteria for Optimization of Chromatographic Multicomponent Separations

This study presents a Chromatographic Optimization Function (COF) to optimize chromatographic separation conditions. The COF proposed herein provides several advantages over conventional COFs, including the ability to eliminate the ambiguous selection of the weighting factors and easily obtain the acceptable or maximum resolution in the shortest separation time. The parameters used to construct this COF are in the form of sigmoidal functions to reduce the weight of the response for less acceptable conditions and to filter out undesired situations. In addition, resolution between peaks, length of separation time, and number of peaks separated are used as parameters for constructing the proposed COF. Closely examining the performance of the COF for both simulated and experimental chromatographic separations reveals an adequate correlation with human judgment and, also, creates no problems in selecting weighting factors.     

气相色谱智能优化在卤代烃分析中的应用

本文研究了气相色谱柱温智能优化软件在卤代烃毒物分析中的应用。智能优化使得包含多个卤代烃与烃的混合样品达到了满意的分离效果，保留值预测误差在１．１％以内，吻合程度很好。     

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。     

Analysis of Malodorous Sulfur Gases and Volatile Organometalloid Compounds in Landfill Gas Emissions Using Capillary Gas Chromatography with Programmed Temperature Vaporization Injection and Atomic Emission Detection

Volatile compounds containing Group V and Group VI elements in landfill gases are of concern as a source of toxic pollutants and unpleasant odors. Conventional analytical techniques for these compounds e.g. ICP-MS, ICP-AES are complicated, expensive and time consuming. The use of a simple programmed temperature vaporization injection (PTV) technique coupled to gas chromatography with atomic emission detection (GC-AED) has been successfully demonstrated to identify compounds containing arsenic, antimony, and sulfur in landfill gas. With an adapted PTV injection system (using a combination of a ten-port and a six-port Valco valves), problems associated with AED discharge tube damage due to high carrier gas flow rate during sample loading can be overcome. The gas samples generated from both a laboratory biowaste digester and a domestic landfill site were characterized using these techniques. Large sample gas volumes were adsorbed onto a cooled sorbent trap containing Porapak Q, followed by rapid liberation onto a porous layer open tubular column (PLOT) using programmed thermal desorption. Arsenic and antimony were also detected in the landfill leachate collected from the same landfill site using hydride generation-atomic absorption spectrometry (Hy-AAS). The efficiency of different traps has also been compared.     

Optimization of dynamic headspace sampling for the analysis of trace volatile components of grape juice: Use of a PTV injector for intermediate trapping

The use of a programmed temperature vaporizing (PTV) injector has been evaluated for the on-line concentration and injection of trace organic compounds either sampled from the head-space above grape juices or purged from solution. The Simplex method was used to improve the sensitivity of the method by optimization of the experimental conditions.     

Determination of Optimum pH For The Analysis Of Inorganic Phosphate Mixtures By 31P Nuclear Magnetic Resonance Spectroscopy by a Simplex Procedure

Abstract

The nuclear magnetic resonance chemical shifts of the lower polyphosphate compounds are strongly dependent on the hydrogen ion concentration of the solution, both absolutely and relative to each other. At an optimum pH, the chemical shifts of pyrophosphate and tripolyphosphate will be most widely separated, and these two compounds can be determined in the presence of each other and in the presence of higher polyphosphates. The univariate simplex procedure found the optimum pH in ten trials, but required two more measurements to define the minimum width of the maximum response region, pH 8.4 to 8.7     

Simplex optimization of acoustic assay for plasminogen activators

This article discusses the optimization of a newly developed method for measuring the activity of plasminogen activators using a thickness-shear-mode acoustic sensor. A variable-size simplex algorithm was used for optimization. Preliminary tests were performed to design the first simplex. A desirability function was defined to translate each performance value to a membership value of 0 to 1. If there was more than one performance variable, their membership values were translated to an aggregated membership value using another function that considers their individual influence on sensor performance. Two rounds of optimization were carried out for streptokinase followed by a single optimization for tissue-type plasminogen activator. In the last optimization, ratios of control variables were used in order to reduce the number of parameters and to formulate easily adjustable assay conditions. The results showed the usefulness of the simplex method for optimizing this type of assay, and the importance of preliminary tests and prior knowledge in providing rapid convergence using fewer experiments. The optimized plasminogen activator assay can be considered a reference method for measurement of all members of this drug class.     

单纯形最优化法测定三元配合物组成比的研究

本文运用单纯形最优化法，测定了Ｖ（Ｖ）－ＰＡＲ－Ｈ２Ｏ２以及Ｗ（Ⅵ）ＰＶ－ＣＴＭＡＢ三元配合物的组成比。提出了对应于三元配合物的λｍａｘ处二元配合物也有部分吸收时的二种处理办法及体系最初酸度调节的新看法，并经上述三元配合物体系，验证了方法的可行性，进一步完善了单纯形最优化法测配合物组成比这一手段。     

Simplex optimization of a programmed temperature capillary gas chromatographic separation

The modified simplex algorithm proposed by Nelder and Mead has been used to optimize the separation by temperature programmed capillary GC, of volatile compounds present in alcoholic beverages. An adequate objective function, CRF, based on the separation factor of Kaiser has been used for the optimization process. A factorial design was initially performed to verify the relationship between the several parameters of interest. Following this, the optimization was executed and a surface adjusted within the set of experimental data.     

Injection by Programmed Temperature Vaporization Injection (PTV) of Gaseous Samples for Gas Chromatography – Atomic Emission Spectrometry (GC-AED)

Programmed temperature vaporization injection (PTV) coupled to gas chromatography and atomic emission detector (AED) has been studied for large volume injection of gaseous samples. As examples of the effectiveness of the technique, the results of the analysis of a series of headspace samples of foods such as garlic and onion, and of landfill gases are presented. The volumes of gaseous samples reconcentrated varied from a few milliliters up to liters depending on analyte dilution, through focusing onto a sorbent trap, then rapid liberation into the GC-AED system by programmed thermal desorption. Despite the high carrier gas flow rates associated with direct PTV-GC, AED performance and sensitivity were unaffected. The detailed elemental information obtained from the PTV-GC-AED analyses was confirmed using a PTV coupled to a gas chromatograph with ion trap detector mass spectrometer as detector (PTV-GC-ITD/MS).     

单纯形优化高效液相色谱法分离测定维生素E的各种异构体

本文用计算机辅助单纯形优化高效液相色谱法分离、测定了精炼植物油副产物中维生索E的各种异构体。探讨了单纯形优化法指导高效液相色谱选择分离的实验条件,并编写了实用的计算机程序。实验结果表明,本法可使比较困难的条件选择工作有章可循,从而提高工作效率。     

Programmed Temperature Vaporization Injection (PTV) in the Analysis by Gas Chromatography-Mass Spectrometry (GC-MS) of the Constituents of Landfill Gas

Abstract

Trace volatile compounds emitted from both domestic and industrial landfills have been identified by programmed temperature vaporization injection (PTV) coupled to gas chromatography with detection by ion-trap mass spectrometry (GC-ITD/MS). The PTV injection system has been developed using a combination of two six-port valves to achieve problems of interference in GC-MS while loading sample. A large volume of landfill gas was re-concentrated onto a sorbent trap, then rapidly liberated into the GC-ITD/MS system by programmed thermal desorption. Using this method, trace volatile compounds in gases from both domestic and industrial landfills such as aromatic hydrocarbons, terpenes, chlorinated hydrocarbons, and sulfur compounds can be identified and quantified.     

气相色谱法分析天然气中氦氖氢

报道了用气相色谱法分析氦氖氢的各项条件试验,并最后确定了样品的最佳色谱条件,建立了天然气中同时测定氦氖氢的分析方法。     

Gas Chromatographic Analysis of Phenolic Compounds from Lignin

Abstract

This paper describes the separation and identification of phenolics derived from lignin, a major component of wood, by gas chromatography (G.C.) using a Tenax GC column.     

分析化学计算中单纯形法一种新的收敛准则研究

本文根据误差理论提出了单纯形法收敛准则的一种改进,导出了收敛精度计算式,并用实验进行了验证。     

化学计量学方法用于多环芳烃液相色谱分离条件优化

本文报道化学计量学方法用于多环芳烃(PAHs)液相色谱分离条件的优化.使用均匀实验设计法,以乙腈在线性梯度展开时的初始浓度和线性梯度的斜率为优化参数,对16种多环芳烃混合体系进行液相色谱分离条件优化,采用遗传算法和退火神经网络方法建立了有效的分离条件预测模型.对模型所预测的最佳分离条件进行试验,分离结果满意.