Polarographic Determination of Accelerators, Antioxidants, and Other Rubber Chemicals. I.

1959 ◽  
Vol 32 (4) ◽  
pp. 1254-1268
Author(s):  
F. Mocker
Keyword(s):  
Zinc Oxide ◽  
Quantitative Determination ◽  
Raw Materials ◽  
Zinc Stearate ◽  
Zinc Salt ◽  
Polarographic Method ◽  
Experimental Conditions ◽  
Methanolic Extracts ◽  
Rubber Compounds

Abstract The present paper shows that the Polarographic method for the determination of rubber additives (rubber chemicals) delivers fully usable results. The following points are discussed : 1. The method is qualified for a rapid quantitative determination of MBT and 2-mercaptobenzimidazole in raw materials control. 2. The zinc salt of MBT can be indirectly determined after its decomposition with acid. 3. MBT and 2-mercaptobenzimidazole can be determined directly in the methanolic extracts of masterbatches. 4. As with the masterbatches, MBT can be determined directly in the extracts of rubber stocks and vulcanizates when zinc oxide is absent. Magnesium oxide or zinc stearate do not interfere. 5. Experimental conditions are given which permit quantitative determinations of MBT in the presence of zinc oxide in uncured and cured rubber compounds. 6. The experiments have shown that the method is applicable to complex recipes containing MBT as the only accelerator. Of course, the limit of error is higher, that is, around −5%. The investigations are being continued and the results will be presented at a later date.

The Quantitative Determination of Rubber Chemicals

1957 ◽  
Vol 30 (4) ◽  
pp. 1017-1026 ◽  
Author(s):  
Otto Lorenz ◽  
Elisabeth Echte
Keyword(s):  
Quantitative Determination ◽  
Chloride Solution ◽  
Silver Salt ◽  
Stannous Chloride ◽  
Zinc Salt ◽  
Iodine Solution ◽  
Experimental Conditions ◽  
Zinc Salts ◽  
Free Sulfur

Abstract 1. Both the precipitation of mercaptobenzothiazole as a silver salt and its oxidation with an iodine solution to a disulfide may be utilized for quantitative determination. 2. Zinc benzothiazolyl mercaptide can be determined iodometrically, either directly or indirectly, after being cleaved by acids. 3. Benzothiazolyl disulfide is determined as mercaptobenzothiazole after reduction with acidic stannous chloride solution. 4. A procedure for the determination of a mixture of mercaptobenzothiazole, zinc benzothiazolyl mercaptide, and dibenzothiazolyl disulfide is described. 5. Experimental conditions are indicated, under which the quantitative determination of free sulfur is possible in the presence of mercaptobenzothiazole, its zinc salt, the disulfide, and the zinc salts of fat acids. In all cases the uncombined sulfur is determined after its conversin to thiocyanate by an argentometric conductivity titration of the thiocyanate.

scholarly journals A New Approach for the Determination of Benzocaine and Procaine in Pharmaceuticals by Single-Sweep Polarography

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Serhij Plotycya ◽  
Oksana Strontsitska ◽  
Solomiya Pysarevska ◽  
Mykola Blazheyevskiy ◽  
Liliya Dubenska
Keyword(s):  
Quantitative Determination ◽  
Oxidation Products ◽  
Polarographic Reduction ◽  
Polarographic Method ◽  
Experimental Conditions ◽  
New Approach ◽  
Reduction Current ◽  
Product Specifications ◽  
Good Agreement

A new polarographic method for the determination of benzocaine and procaine based on the polarographic reduction of their chemically obtained oxidation products with potassium peroxymonosulfate is developed. Experimental conditions affecting quantitative yield of benzocaine and procaine oxidation products such as рH, oxidation time, reagents’ concentration, and temperature are explored. It is shown that the reduction current changes in a linear fashion (R=0.999) with increasing concentration of anesthetics over a concentration range of 1·10−6 - 5·10−5 mol L−1. The calculated limits of detection (LOD) for benzocaine and procaine are found to be 5.6·10−6 and 6·10−6 mol L−1, respectively. In the present study, quantitative polarographic determination of benzocaine in Farisil tablets and “Septolete Plus” lozenges and procaine in solution for injections is performed. The results of the analysis are in good agreement with the product specifications described in the quality certificates. The possibility of quantitative determination of benzocaine and procaine in pharmaceuticals is confirmed.

scholarly journals Quantitative Determination of Terramycin by Polarographic Method

1955 ◽  
Vol 4 (1) ◽  
pp. 30-34 ◽  
Author(s):  
TAKEJI NOTO ◽  
GAKU MATSUOKA
Keyword(s):  
Quantitative Determination ◽  
Polarographic Method

The Determination of Free Sulfur in Vulcanizates by a Polarographic Method

1952 ◽  
Vol 25 (1) ◽  
pp. 161-166 ◽  
Author(s):  
F. C. J. Poulton ◽  
L. Tarrant
Keyword(s):  
Quantitative Determination ◽  
Acetone Extract ◽  
Polarographic Method ◽  
The Common ◽  
Free Sulfur ◽  
Working Processes

Abstract The polarographic method offers a rapid and accurate means of determining the “true” free sulfur in vulcanizates. In the case of single estimations, the test takes approximately as long as the copper-spiral method, but for multiple or replicate testing it is much quicker. Since the determination is made directly on the acetone extract, it was necessary to examine at some length the possibility of interference from other ingredients of the extract. It is shown that most of the common accelerators and antioxidants are not likely to interfere, and promising methods of determining certain of these substances were revealed. Thus MBT, MBTS, TCA, A11, ONV, ZDC, TMT, TET, Ureka, and some of the Nonox series of antioxidants give regular Polarographic waves readily distinguishable from that of sulfur, and the development of working processes for their determination should not present any great difficulties. Other accelerators and antioxidants, notably ZIX, some Nonox antioxidants and Agerite White, while showing Polarographic activity, give poor curves in the pyridine electrolyte. No doubt in other base solutions the form of curve could be improved, and their quantitative determination would then follow.

2-(2'- Chloro Phenyl)- 5- (2'-Hydroxyl Phenyl)-1,3,4-Oxadiazole as a Florescent Probe for DNA Determination

2011 ◽  
Vol 301-303 ◽  
pp. 361-365
Author(s):  
Mei Ding ◽  
Ying Jie Lei ◽  
Ou Yang Jie
Keyword(s):  
Experimental Data ◽  
Fluorescence Quenching ◽  
Quantitative Determination ◽  
Fluorescent Probe ◽  
Fluorescence Intensity ◽  
Dna Analysis ◽  
Fluorescence Spectrometry ◽  
Experimental Conditions ◽  
Convenient Synthesis

In recent years, fluorescence spectrometry was widely used in quantitative determination of DNA. In this paper, a convenient synthesis of a new fluorescent 2-(2'- Chloro phenyl)- 5- (2'- hydroxyl phenyl)-1,3,4-oxadiazole (HOXD) was realized. Experimental data showed that fluorescence of HOXD could be quenched by DNA and the decreased fluorescence intensity of HOXD resulting from fluorescence quenching is proportional to DNA concentrations suggesting that HOXD could be used as a new fluorescent probe for quantitative determination of DNA. Optimal experimental conditions for DNA analysis were also studied in the paper.

scholarly journals Isolation and determination of some physical and chemical properties of polysaccharide from black elderberry flowers

2020 ◽  
pp. 95-101
Author(s):  
Игорь Анатольевич Сычев ◽  
Татьяна Викторовна Алимкина
Keyword(s):  
Medicinal Plant ◽  
Quantitative Determination ◽  
Raw Materials ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Plant Raw Materials ◽  
Physical And Chemical ◽  
And Chemical Properties

Предложенный метод количественного определения восстанавливающих моносахаридов в полисахариде позволяет проводить стандартизацию лекарственного растительного сырья цветков бузины черной. На способ стандартизации лекарственного растительного сырья цветков бузины черной по содержанию восстанавливающих моносахаридов в полисахариде оформлено рационализаторское предложение № 1373 от 29.02.2016 г. РязГМУ. The proposed method for the quantitative determination of reducing monosaccharides in a polysaccharide makes it possible to standardize medicinal plant raw materials of black elderberry flowers. On the method of standardization of medicinal plant raw materials of black elderberry flowers in terms of the content of reducing monosaccharides in the polysaccharide, a rationalization proposal No. 1373 dated February 29, 2016 RyazSMU was issued.

Sign in / Sign up

Export Citation Format

Share Document