More About pH

What is pH?

pH is a unit of measurement which describes the acidity or alkalinity of a solution, measured on a scale from 0 to 14. The term pH is derived from a mathematical symbol for negative logarithm and a chemical symbol for Hydrogen. The pH of a product serves as a vital parameter for many industrial processes and quality control standards.

A buffer is a substance that minimizes changes in the pH of a solution. Buffers maintain the pH of the solution by adjusting the direction of their chemical reactions (dissociating or re-associating) in response to increases or decreases in H+ ion concentration that can be caused by other substances entering or exiting the solution. They are mostly used for calibrating the pH measuring system such as electrodes and pH meters.

Temperature dependence of the pH

The pH value of a solution varies with the temperature. In our product label, it is stated that the pH values of our standard buffer solutions are measured at 25°C and different conditions are also available upon request. The pH temperature correlation table of our standard buffer solutions will be printed in our certificates and product labels.


In the pharmaceutical industry, it is vital to determine suitable pH for a given drug in solution at the early stages of drug discovery. From a formulation perspective, it is crucial to control the pH of a product to minimize drug degradation, to improve patient comfort and compliance, and to improve delivery. Higher pH values of liquids are often required to make the drug more soluble, and to maintain good stability and adequate shelf life.


In the food and beverage industry, pH is involved in the safety and preservation of foods, taste, and flavor. pH of milk is tested within range 6.8 to 7.0 and it is tested for impurities and signs of infection upon collection and at point of delivery. In processes such as sterilization, pH is checked since a lower value helps to speed up the process. The milk used for cheese manufacturing must be of excellent quality and its pH value contributes to the texture of the cheese. pH is also checked during cheese preparation, souring of milk and cream maturation as well as pathogen multiplication of the fresh and soft variety, which is slowed down considerably by ensuring that the pH stays in the 4.1 to 5.3 region.


In the semiconductor industry, the pH of solutions is an important controlling parameter in the evaluation of the aqueous phase for photocatalytic degradation reaction. It affects the adsorption and dissociation of the substrate, catalyst surface charge, oxidation potential of the valence band, and other physiochemical properties.


In refinery and petrochemical processes, sour water corrosion is a common problem when processing crude. As the crude contains contaminants like sulphur, salts, and gases such as H2S when dissolved with water it forms sour water. If the pH-controlled is below 5.5, the sour water may corrode and damages all fixed assets or causes dangerous environmental impacts. Measuring the pH can help in the treatment of the corrosive sour water that is produced in the process.


The study of soil pH is very important in agriculture due to the fact that soil pH regulates plant nutrient by controlling the chemical forms of the different nutrients and also affect their chemical reactions. As a result, soil and crop productivities are linked with soil pH value. The optimum range for most agricultural crops is between 5.5 and 7.5.

If the vegetable garden pH is too acidic, certain nutrients become less available, phosphorus in particular, while other nutrients, like aluminum and manganese, can become toxic. Acidic pH levels are also unwelcoming to beneficial soil bacteria.