Comparison of the results of color determination in the KN-51 and FÉKN-56 colorimeters

Conclusions The FÉKN-56 colorimeter enables us to improve the accuracy of a color determination of a color determination of residual raffinate by a factor of 5 in comparison with determinations in the KN-51 colorimeter.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 1, pp. 57–58, January, 1970.     

Highly sensitive and selective spectrofluorimetric determination of nitrite in food products with a novel fluorogenic probe

A simple, sensitive, selective and convenient spectrofluorimetric method for detection of nitrite has been successfully developed. This method is based on the highly efficient and specific reaction of nitric oxide with a dihydropyridine derivative to form a highly fluorescent pyridine derivative, in aqueous solution. Under optimum conditions, excellent detection linear range was achieved from 0.2 to 4.5 μmol L⁻¹ with a detection limit of 0.02 μmol L⁻¹ (S/N = 3), lower than or comparable to most of other spectrofluorimetric methods. The relative standard deviation for ten determinations of 2.0 μmol L⁻¹ nitrite was 1.0%. The proposed method has been applied to determine nitrite levels in food products with recoveries of 93.3%–103.5%.     

Method of determination of trace quantities of copper,lead, and zinc in naphthas

Summary A procedure has been developed for the spectral determination of trace-contaminant copper, lead, and arsenic in naphthas; the method consists of dropping a sample of naphtha into a heated electrode, thus evaporating the naphtha, and then photographing the spectrum of the dry residue. The conditions that were chosen, particularly the use of an appropriate buffer, have made it possible to achieve the following sensitivities in the determination: Copper 2·10^–8%, lead 5·10^–8%, and arsenic 1 ·10^–7%, The respective coefficients of variation in the determinations of these elements are 26, 30, and 25%.The method is being used at BashNII NP for regular quality control on the feedstock entering the catalytic reforming unit of the Novo-Ufa refinery.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 55–59, April, 1973.     

Potentiometric method of determination of base numbers of nitrogen-containing additives

Summary For the determination of base numbers of succinimide additives, a method has been proposed, consisting of a potentiometric titration in nonaqueous medium. The recommended solvent is a mixture of chloroform and glacial acetic acid in 1/1 ratio, and the titrant is a 0.1 N solution of perchloric acid in glacial acetic acid.The results of base number determinations on succinimide additives by the proposed method are higher than those obtained by GOST 11362-65; the results by the proposed method are in essential agreement with the theoretical values.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 5, pp. 55–56, May, 1973.     

Determination of cadmium and lead in fruit juices by stripping chronopotentiometry and comparison of two sample pretreatment procedures

A method for the determination of cadmium and lead in apple and pear fruit juices by stripping chronopotentiometry (SCP) is described. The results obtained after previous digestion of the sample with concentrated sulphuric acid and dry-ashing (sample pretreatment procedure “A”) and after a treatment with concentrated hydrochloric acid followed by heating in hot water bath (sample pretreatment procedure “B”) were compared. The sample pretreatment procedures were tested on real fruit juice samples and all data confirmed that the efficiency of procedure A was greater than procedure B. In particular, for samples treated with procedure A, good linearity was obtained in the range of examined concentration as is shown by the determination coefficients that were 0.998 (n = 4) for cadmium and 0.996 (n = 4) for lead. Recoveries of 86–104% for cadmium and of 87–102% for lead were obtained from a sample spiked at different levels. The accuracy was also evaluated by means of a matching reference sample of spiked skim milk powder (BCR 150—Community Bureau of Reference) to prove the reliability of the method. The detection limits were 2.0 ng g⁻¹ for cadmium and 4.8 ng g⁻¹ for lead. The relative standard deviations (mean of nine determinations), evaluated on a real sample, were 7.8% and 6.5% respectively. The average content was in the range not detectable–3.0 ng g⁻¹ for cadmium and 8.2–21.3 ng g⁻¹ for lead.     

乳浊液进样-火焰原子吸收光谱法测定润滑油添加剂中的锌、铅

将乳浊液进样技术应用于火焰原子吸收光谱法 ,成功地测定了添加剂中的锌、铅 ,建立了测定润滑油添加剂中锌和铅的快速分析方法。对乳化剂的选择、背景吸收干扰、空白溶液的选择及检出限进行了考察。测定结果与灰化法-火焰原子吸收光谱法一致 ,相对误差小于± 2 5% ,t检验表明两种方法之间无显著性差异。相对标准偏差小于3 0 % ,锌的检出限 0 0 68mg/L、铅的检出限 0 2 7mg/L。本方法简便、快速、准确。     

Quantitative analysis of tin and lead in TDI combustion catalyst

Abstract

A convenient method for quantitative analysis of tin and lead in 2,4—tolylene diisocyanate (TDI) combustion catalyst, which contains Tin, lead and their compounds or complexes, is described. The method consists of decomposition of samples by sodium hydroxide fusion, extraction with hydrochloric acid and complexation by EDTA, followed by titration with zinc chloride standard titration solution, which give rise to a precise content of tin and lead respectively in one conical flask.     

Use of nitrated oil as an anticorrosive additive for commercial emulsols

Conclusions Addition of 20–30 wt.% of nitrated oil to É-1 and É-2 emulsols, manufactured in accordance with requirements of GOST 1975-53, improves the anticorrosion properties of the lubricant-cooling liquids made from these emulsols, without reducing their cutting activity.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 11, pp. 41–43, November, 1970.     

化学驱油中浊度法测定HPAM浓度的准确性

大庆油田聚合物驱和三元复合驱中普遍采用冰醋酸－次氯酸钠浊度法测定ＨＰＡＭ浓度,由于应用条件复杂多变,测定结果的准确性不好。实验考察了ＨＰＡＭ的水解度,分子量,水质碱、表面活性剂ＯＲＳ－４１及ＨＰＡＭ生产厂家对测定结果的影响 发现除ＯＲＳ－４１外,其余因素的影响都很大,这使实际生产中很难制作出合乎该法要求的标准工作曲线。     

A multicommuted flow system for fast screening/sequential spectrophotometric determination of dichromate,salicylic acid,hydrogen peroxide and starch in milk samples

In this work a multicommuted flow system for the sequential screening/determination of dichromate, salicylic acid, hydrogen peroxide and starch in milk samples was developed. The concept of multicommutation in flow injection analysis was chosen, resulting in an environmentally friendly system with minimal consumption of reagents and waste generation. The proposed approach is based on a simple binary DETECT or NO-DETECT response, thereby making it possible to determine analytes quickly, with high performance and easy operation. For dichromate determination, the proposed method was based on the reaction between Cr(VI) and 1,5-diphenylcarbazide, enabling a linear working range response, between 1.0 and 10.4 mg L⁻¹, (R = 0.999). In order to determine salicylic acid, the proposed method was based on a complexation reaction of Fe(III) and salicylic acid, with the linear working range response from 103.6 to 414.3 mg L⁻¹ (7.5 × 10⁻⁴–3.0 × 10⁻³ mol L⁻¹) (R = 0.999). The hydrogen peroxide determination was based on the oxidation reaction of hydrogen peroxide with vanadium oxide (V) in an acid environment, with a linear working range of 10.0–200.0 mg L⁻¹ (R = 0.996). Starch determination was based on the complex reaction of starch and triiodide, with a linear working range of 12.5–150.0 mg L⁻¹ (R = 0.999). The mean sampling rate for the four species was 83 determinations per hour. Performance curves were used to verify the quantity of false positives and false negatives. Addition and recovery tests were used for validation of the proposed procedures, resulting in variation between 90.1 and 108.7% for three different samples.     

Estimation of the Surface Tension of a Pure Liquid

Abstract

Pure component method for surface tension estimation is presented as is a method based upon critical properties and molecular weight of pure components. This method is judged most accurate when estimated values are compared with experimental determinations. The purposed correlation is valid for polar and nonpolar components with an acceptable percent error.     

Determination of admixtures of isobutylene and ethyl alcohol in ethyl chloride by gas-liquid chromatography

Conclusions The determination of isobutylene and ethyl alcohol present as impurities in ethyl chloride in amounts upwards of 0.005% is performed in a KhL-4 apparatus with helium as carrier gas.The isobutylene content is determined in a column (6 m) with TZK, modified with Vaseline oil and sodium carbonate; propane, isobutane, or n-butane are used as the internal standard.The ethyl alcohol content is determined in a two-section column packed with Spherokhrom-1 with PÉG-40° (column length 2 m) and 15% of tricresyl phosphate (column length 3 m); the internal standard in this case is benzene dissolved in toluene.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 58–60, March, 1970.     

High contents of cadmium,lead, zinc and copper in popular fishery products sold in Turkish supermarkets

Selected toxic (cadmium, lead) and essential (zinc and copper) trace metals were determined by means of differential pulse stripping anodic voltammetry (DPSAV) in some different brands and kinds of fishery products purchased from the popular supermarkets of Turkey. Among the fishery products, the highest concentration of cadmium, lead, zinc and copper were found in the frozen anchovy (494.2 μg/kg, 314.2 μg/kg, 566 mg/kg, 45.7 mg/kg, respectively). While the canned anchovy fillet had the lowest cadmium (25.1 μg/kg), zinc (33.8 mg/kg) and copper (7.1 mg/kg) concentrations, canned tuna fish (Brand A) had the lowest lead (76.1 μg/kg). The concentrations of all toxic and essential elements in the selected products were high and often exceeded legal limits set by health authorities. Therefore these products must be monitored more often.     

Spectral determination of sodium in distillate gas turbine fuels

Summary A method for the quantitative determination of sodium in distillate gas turbine fuels without their prior ashing has been developed. The sensitivity of reliable determinations (maintaining a straight line for the calibration curve in S-log C coordinates) is 10^–1% Standard equipment and simple methods have been used.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 8, pp. 53–55, August, 1967.     

Synchronous fluorescence and multivariate classification analysis as a screening tool for determining Sudan I dye in culinary spices

Spices are a globally traded commodity which has been found to be adulterated with forbidden Sudan dyes. This work proposes a screening method for determining the adulteration of paprika varieties (mild, hot and smoked) with Sudan I dye, based on constant-wavelength synchronous fluorescence spectroscopy with multivariate classification. Different wavelength-intervals (Δλ) were evaluated. Classification models were built with Partial Least Squares-Discriminant Analysis (PLS-DA) at two Sudan I dye concentration levels (1 and 5 mg L⁻¹) and they were tested with samples at a lower level (0.5 mg L⁻¹). Classification results were quite satisfactory when a strategy based on first-derivative spectra was used for improving classification results. Δλ = 60 nm was chosen as the optimum wavelength interval giving a 100% of sensitivity and specificity. These results are promising because the risk of assigning adulterated samples as safe to be consumed is highly minimized. The proposed method is feasible, rapid and simple taking advantage of Sudan I fluorescence phenomena in a direct way.     

Cu-ZnO/HZSM-5催化剂的制备、表征及催化性能

采用共沉淀沉积法制备了不同Zn含量的Cu ZnO/HZSM 5双功能催化剂,利用XRD、BET、H2 TPR等手段进行表征,并应用于CO2加氢合成二甲醚的反应中。考察了Zn含量对催化剂前驱体晶相结构以及对焙烧后催化剂的比表面积、平均晶粒大小、还原性能以及催化活性等的影响。研究结果表明,催化剂中w(Zn)=28%时,前驱体中含有较多的绿铜锌矿和单斜绿铜锌矿晶相,焙烧后的催化剂比表面积较大,CuO与ZnO的平均晶粒较小,还原峰温度较低,催化活性较高。     

The Phazaphot instrument for determination of the low-temperature properties of petroleum products

A new method of determining the solid point and flow point of crude oil and petroleum products, crystallization/melting of waxes in petroleum products, and the Phazaphot instrument for implementing the method are described. The method consists of recording the intensity of light mirror-reflected from the surface of the sample during structural transitions when the temperature changes. The new principle of measurements allowed significantly simplifying implementation of the method, making the determinations faster, and expanding the range of objects investigated and problems solved. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 1, pp. 48–52, January–February, 2006.     

Bio-sorption for tannery effluent treatment using eggshell wastes; kinetics,isotherm and thermodynamic study

Since, cobalt, zinc, mercury and lead ions are high toxic heavy metals; this work aims to investigate the efficiency of eggshell as a low cost sorbent for their ions from aqueous solution. Adsorption of heavy metals on surfaces of eggshell obeyed second order kinetics. Adsorption isotherm belonged to Freundlich model and displayed multilayer adsorption. The maximum adsorption capacity was estimated as 204, 153, 121 and 98 mg/g for Co³⁺, Zn²⁺, Hg²⁺ and Pb²⁺ respectively. The values of free energy of adsorption evidenced the physical adsorption occurrence. It is demonstrated that eggshell, as an industrial waste, was efficiently used as an adsorbent for wastewater treatment. Eggshells powder removed efficiently heavy metal ions from a tannery wastewater and removal efficiency reached up to 99%.     

Estimation of the Surface Tension of a Pure Liquid

Pure component method for surface tension estimation is presented as is a method based upon critical properties and molecular weight of pure components. This method is judged most accurate when estimated values are compared with experimental determinations. The purposed correlation is valid for polar and nonpolar components with an acceptable percent error.     

含油气层早期产能预测方法初探

根据油气层热解、试油等资料，提出了３种预测油气层早期产能的方法：一种是地质类比法，它是根据预测层位与对比模型有相似的油气水界面和构造来实现的；另两种是统计分析法和产油指数法，它们是根据数理统计原理，从不同角度对已经试油的层位进行系统分析，建立产能与多种参数的关系方程进行预测的。