This study presents the composition of the state primary standard of the pH indicator of hydrogen ion activity in aqueous solutions GET 54-2019. The standard includes the measures of acidity and a ...coulometric titrator, with a hydrogen index (HI) measurement range of 0.01–12.00. The methods and techniques applied for reproducing the HI values of GET 54-2019 reduced the total standard uncertainty to 0.0012, corresponding to the accuracy of the gold standard analogs of pH standards. The study also presents the metrological characteristics of GET 54-2019 and the results of key international comparisons to determine the HI of the borax buffer CCQM-K19.2018. The state primary pH standard GET 54-2019 is used in several industries and science and technology fields; pH measurement is especially significant in the chemical, pharmaceutical, and food industries, where HI control is crucial at all stages of the production cycle. Recently, controlling the pollution of water bodies with human waste products has become a pressing need; consequently, pH measurements have become essential in environmental monitoring. The scope of GET 54-2019 has expanded due to the increased HI measurement range in strongly acidic environments. In this regard, improving the pH measurement accuracy in studies on acidity of the human gastrointestinal tract can significantly reduce the risk of false diagnosis.
The enormous need for support of measurements of the hydrogen index (pH) in various branches of industry and the national economy of Russia make measurement of pH one of the most important methods ...for monitoring aqueous media. In 2013 work was carried out to introduce into the State Register of Means of Measurement of the Russian Federation a buffer solution and titration standard with a pH value of 7.00, a 2nd order working standard for pH which is one of the nonstandard solutions most in demand for verification and calibration of instruments for measuring pH. The metrological characteristics of the 2nd order working standard for pH have been confirmed in pilot comparisons through COOMET (COOMET project 655/RU/15). The results of a pilot comparison for determination of the pH of a phosphate buffer solution with pH=7.00 are presented here. 8 metrological institutes and 10 metrological organizations took part in the comparisons. The results showed that the overwhelming majority of the participants in the comparisons obtained results for the pH measurements with an uncertainty that did not exceed ±0.03 of the average value, which is an acceptable criterion for pH measurements.
This work is devoted to the study on effects of mass variation of fine-dispersed catalytic plating to a potential of the hydrogen electrode, as well as, establishment of the optimal electrochemical ...plating time of the catalytic coating of the measuring electrodes used in the Russian State Primary Standard of pH in aqueous solutions GET 54-2011. The experiments were carried out by a measuring system of precision measuring devices, using a silver chloride sensor as a reference electrode, to establish the change of the potential difference. The necessary time for the plating of the hydrogen electrode was determined. It is in the range of 7 to 8 minutes with 45 mA current.
The main aim of the work was high-precision determination of potassium hydrophthalate content by coulometric system with horizontal type cell. The coulometric system was developed for functioning of ...the State primary standards of pH GET 54-2011 and pX GET 171-2011 ions activities in liquid media. The coulometric system is necessary to ensure the procedures for monitoring the purity of chemical reagents used in the production of high-cleaning reference substances, which used as working standards. High-clean substances are used to prepare mixtures and solutions for metrology area, particularly they are used in the State primary standards key comparisons, as well as, to direct transfer of units of quantify characteristics of chemical substances used in the calibration or verification procedures of measuring instruments, in certification of standards, in control of precision of measurement methods.
Abstract
In the paper is discribed the preparation method of buffer solution for interlaboratory and international comparisons. This technique was developed by scientists of All-Russian Scientific ...Research Institute of Physicotechnical and Radio Engineering Measurements during the preparation of samples for international comparisons in the field of measuring the hydrogen index of borate buffer solution. According to the measurement results, the offered method allows to prepare the homogeneous and stable buffer solutions.
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