The Research And Application On Measuring Alkalinity And PH Buffering Capacity With The Method Of Electrochemistry

The bicarbonate compounds are widespread in nature, and the bicarbonate in human body is an important substance to maintain blood acid-base balance, which can assist to control the pH within the normal physiological range. For hydrobiontic algae, bicarbonate is also involved in the process of photosynthesis of it. In the day-to-day production of human life, the role of bicarbonate can not be ignored:in the field of clinical medicine, due to its non-metabolism and no side effect for human body, bicarbonate dialysate is the ideal dialysis preparations for treating complications such as acidosis. In food and drinks, bicarbonate compounds can effectively maintain the stability of the pH and restrain the growth of various molds, so that it is an ideal preservative.Bicarbonate compounds can also be applied in environmental purification and flame retardants. In view of the excellent effect of bicarbonates, it is particularly important to detect the concentration of bicarbonate in order to make better use of it. This paper will explore the new methods of measuring the concentration of bicarbonate compounds through the example of measuring the bicarbonate in water, namely, the measurement of alkalinity.The traditional methods for detecting alkalinity are acid-base indicator titration and potentiometric titration, both of which needs to add relevant indicators and standard acid solution in measurement, which makes it difficult to maintain the stability of pH of the test sample during the measurement and may cause interference due to some unknown reaction. When introducing acid, it may damage certain components of the sample. Therefore, creating an alkalinity measurement method without the introduction of standard acid solution and the indicators will play a vital role in future alkalinity measurement study.Hydroquinone is added to the different concentrations of buffer solution to conduct differential pulse test, and it can be found that when the buffer solution has a relatively low concentration, the hydroquinone can cause a pH gradient in the process of oxidation due to the mutation of hydrogenionconcentration on the surface of the electrode, so there will be two oxidation peaks. Through the tests conducted by different pH values in different types of buffer solutions, it can be found that the first oxidation peak of hydroquinone poses a positive linear relationship with the concentration of buffer solution. Therefore, a method to measure alkalinity without adding acid is created based on this and when compared with the traditional method, the results turn out to be consistent.pH buffering capacity has gained widespread concern in the industrial and agricultural production and physiology. Usually, the measurement method of buffering capacity is pH meter, namely, to add strong acid or alkali solution to the solution and observe the change of pH, and use the formula proposed by Van to calculate the buffering capacity. As the traditional method of measuring alkalinity, adding acid or alkali will undermine the stability of the sample and interfere with some measurements. The paper studies the reduction process of p-benzoquinone on the electrode by adopting square wave voltammetry and finds that in low concentrations of buffer solution, there is also a good linear relationship between the first reduction peak current value of p-benzoquinone and buffer concentration. Combined with the relationship between buffer solution concentration and buffering capacity and based on the above experiment, a method to measure pH buffering capacity without adding acid is created. This paper conducts a measurement of the buffering capacity of the pineapple juice; the result turns out to be consistent with what has got by using traditional method.