Analytical methods for the determination of alkylpolyglucosides

This paper describes the repertoire of analytical methods which is currently available for the determination of Alkylpolyglucosides (APGs). The methods range from chromatographic techniques (hightemperature gas chromatography, high-performance liquid chromatography, thin-layer chromatography) to methods which allow a fast and easy (but unselective) determination of sum parameters. For the first time a derivatization method is described which converts APGs into anionic compounds that can be titrated potentiometrically.     

聚酯亚胺多元醇酸值分析的新方法

聚酯亚胺多元醇酸值是聚氨酯的一个重要指标一通常测定酸值时，一般使用酚酞作为指示剂。但是对于改性聚酯多元醇，用酚酞作为指示剂其终点难以判断，故采用电位滴定法测聚酯亚胺多元醇的酸值，同时使用各种酸碱指示剂用来指示滴定终点，结合两得出一个最件的指示剂。研究表明溴百里酚蓝为测定聚酯亚胺多元醇测定酸值最合适的指示剂。提供了聚酯亚胺多元醇起始电位值与酸值的标准曲线图．能快速、简便地查出相同条件下不同样品的酸值。     

分光光度法快速测定复合肥中有效磷含量

研究了分光光度法快速测定复合肥中有效磷含量的方法,对测定过程的波长、酸度、显色剂用量、显色时间、不同提取时间进行了探讨。在酸性溶液中,磷酸根与钒钼酸铵显色剂反应生成稳定的黄色络合物,在400 nm波长处进行测定,测定结果的相对标准偏差为0.17%~0.40%,回收率为95.30%~107.94%。     

木材防腐剂CCB中有效成分硼的测定方法探讨

采用一种常规化学滴定分析方法对CCB木材防腐剂中的有效成分硼进行分析测定,结果表明:该测定方法的准确度和精密度较高,且操作简便,是一种适合于在工业生产中检测CCB有效成分硼的方法。     

农药沉积利用率喷雾指示剂诱惑红的酶标仪测定方法

诱惑红是一种水溶性染料,近年来被用作农药沉积利用率测定的指示剂.诱惑红的检测方法为高效液相色谱法和分光光度法.高效液相色谱法需要专门的分析仪器,且价格昂贵,可见分光光度计法操作繁琐,试剂用量大,耗时长,均不适宜田间快速高效测定.笔者发展了诱惑红的酶标仪测定方法,简单高效,可批量检测多个样品,且准确度和精密度高,线性关系...     

油脂碘价的快速测定方法

对油脂的碘价测定提出了不改变Ｈａｎｕｓ法操作步骤，只需在测定过程中加入催化剂醋酸汞，使原方法需３０ｍｉｎ完成的测定反应，可在３ｍｉｎ完成。快速法与Ｈａｎｕｓ法测定的碘价相对偏差小于０．８％，快速法的变异系数为０．３１％。     

气氯中硫酸酸雾测定方法的研究

气氯中水分的测定在氯碱生产中是非常重要的,但气氯中含有微量硫酸酸雾对测量的精度有一定的影响,文中较为系统地叙述了测定气氯中硫酸酸雾的原理和过程,具有一定的指导性。     

THE ROLE OF SPECIFIC HEAT IN THE SELECTION OF REFRACTORIES1

A brief discussion of specific heats is given in which particular emphasis is placed upon its determination at high temperatures, the methods which have been used in the past for its determination, and the application of the values in the selection of refractories. The need of determining physical properties of brick which have been in service is pointed out.     

Bestimmung reduzierender Substanzen in Glycerin mit Hilfe einer Transmissionsmessung

Determination of Reducing Compounds in Glycerol by Transmittance Determination The investigation of pure glycerol contain a determination of reducing compounds. A range of different methods for the determination of the limiting value exists, which are described in national and international standards and pharmacopeias. A colouring and/or turbidity, possibly occurring after reaction with corresponding reagents, is judged visually. The subjectivity of the evaluation and the variety of procedures are disadvantageous. A method has been developed which permits as well objective measuring (light transmittance) as application as an universal test. The measuring result of this test can be correlated with the result of the analysis of any standard method. Thus application of several methods for determination is still no longer necessary. Besides the possibility to carry out a graduation of glycerol quality, important criteria of standard methods, as for example reproducibility, sensitivity etc. can reliably be investigated by means of determination of transmittance.     

Short‐chain fatty acids as marker for the degradation of frying fats and oils

The determination of fatty acid composition by gas chromatography as a routine task is established in most laboratories dealing with oils and fats. The scope of this method can be enlarged for a preliminary quality control of used frying fats and oils, which is commonly characterized by the determination of polar compounds and polymerized triacylglycerols. However, for screening purposes the determination of the short‐chain fatty acids C7:0 and C8:0 can give an early indication about the quality of used frying fats and oils.     

Determination of non-spherical particle terminal velocity using particulate expansion data

A new method is proposed for the determination of the terminal velocity of non-spherical particles and compared with experimental data. The method is based on particulate expansion data of fluidized bed and variational model for calculating fluid–particle interphase drag coefficient. Other methods require knowledge of the particle shape, a parameter that is not easy to obtain for real materials. We use pressure drops data in packed bed for indirect determination of particle shape factor which depends on the reliability of coefficients in the Ergun equation. Our data, however, show that these coefficients are system-specific. The proposed method for the determination of non-spherical particle settling velocity in liquid as well as extrapolation to system gas-particles gives results which are in good agreement with experimental data. The method is restricted to particles which can be fluidized particulately by liquid.     

冷原子吸收法测定地化样品中痕量汞

在原子吸收分光光度计上,制定出地化样品中痕量汞的冷原子吸收测定方法。实验结果表明,本方法准确可靠,可测定10-9量级的汞,重现性好,共存元素不干扰汞的测定,可满足地化痕量汞的测定。     

A computerized and integrated approach for heat exchanger network design in multipurpose batch plants

Significant savings in the utility cost of batch plants can be obtained by heat integration. In this study, an integrated mathematical programming approach is developed for the determination of the cost optimal heat exchanger network for multipurpose batch chemical plants. A single step, interactive computer program (BatcHEN) which is developed for the determination of the campaigns (i.e. the set of products which can be produced simultaneously), the heat exchange areas of all possible heat exchangers in the campaigns and finally the heat exchanger network are all discussed. A matrix search algorithm is used for the determination of the campaigns. Heat exchange areas for the possible heat exchangers are found by solving a nonlinear optimization model with a grid search algorithm. Finally the heat exchanger network optimization is modeled as a mixed integer linear programming problem and then solved by the modeling and optimization software GAMS/XA.     

Measurement of electrical conductivity of copper under impulsive loading

A noncontact method of measurement of electrical conductivity of nonmagnetic metals and alloys under impulsive loading is proposed. It is based on experimental determination of the nature of decay of eddy currents in the studied sample, which is a finite size foil disk. Theoretical justification of the proposed method is given. Experiments on determination of copper conductivity at pressures up to 16 GPa are performed.     

Semimicro determination of total fatty acids and unsaponifiable matter

A semimicro method for determining both total fatty acids and unsaponifiable matter in fats, fatty acids, and soap is presented. The procedure involves saponification and recovery of the total fatty acids (which includes the unsaponifiables), removal of the fatty acids with anion exchange resins, and determination of the unsaponifiable matter by weight. The total fatty acid method was evaluated on seven samples and showed a standard deviation from the mean of 0.21%. The unsaponifiable matter determination gives good reproducibility with a standard deviation from the mean of 0.06%. Since this ion exchange is a direct determination of the nonionic components, the results obtained from it should be more accurate and more nearly the true values than the macro extraction method which is empirical. Presented at the annual spring meeting, American Oil Chemists’ Society, Dallas, Tex., April 4–6, 1960.     

Physico-Chemical Studies of the CaO-Ethylene Glycol System. Determination of free lime in industrial products

Optimum conditions for a conductometric determination of free lime in industrial products, using alternating current conductometry are elaborated. The analysis of the variation of the conductivity in dependence on concentration in the temperature (°C) range [25–100] allowed the determination of dissociation parameters of calcium glycolate viz. dissociation constant and equivalent conductivity at infinite dilution, which in turn led to the determination of the calcium glycolate concentration from the measured conductivity. The conductometric determination of free lime is only influenced by the presence of SrO. The water content of the solvent (ETG) must not exceed 0.5%.     

燃烧法测定镀铬溶液中的硫酸

镀铬溶液中硫酸质量浓度的快速测定,是调整镀铬溶液生产的需要.该方法依据钢铁燃烧法测定硫的原理.将镀铬溶液滴入铺有还原铁粉的瓷舟中,用管式炉燃烧法快速测定镀铬溶液中的硫酸,并与称量方法比较,结果表明:该方法简便、快速、准确.     

分光光度法测定废砂浆中铁含量

采用邻啡罗啉分光光度法测定废砂浆中铁含量,探究了废砂浆中重金属铬对测定铁离子含量的影响。结果表明,废砂浆中铁含量测定值为2.61%,相对标准偏差为2.24%,平均回收率为98.92%。该方法对废砂浆中重金属铬的抗干扰性强,精密度及准确度高、快速、简便、成本低,是一种适用于废砂浆中铁含量测定的分析方法。     

微库仑法测定石油及石油产品中的硫含量

在石油化工生产过程中,硫含量的测定是需要严格控制的一项重要指标,也是与发动机的腐蚀及环保排放有关的重要项目。硫的存在还降低了油品的氧化安定性,,使油品颜色变深,产生特殊的气味和讨厌的沉渣而降低油品的质量。炼厂及石油化工装置排放气中的硫化氢、二氧化硫,在空气中还会形成酸雨,污染环境,破坏生态平衡,因此硫含量分析至关重要。分析硫常用的方法有很多:燃灯法、氧弹法、氧瓶燃烧法、微库仑法和荧光法等。本文就微库仑法灵敏度、快速、准确的特点,通过大量的实验,针对各种影响因素进行对比和研究,找到了最佳的分析条件,并选择校正曲线法建立汽油、柴油和重油中硫分析方法。试验表明:上述方法对于不同石油产品中显示出良好的选择性(重复性、再现性和灵敏度),满足了生产过程中不同石油产品中硫含量的检测需要。