What is titration?

• 08 November 2023
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What is titration?

As we mentioned, titration is a method of chemical analysis that is used to determine the concentration of a substance in a sample. In this method, a standard solution with a specific concentration is added to the sample to establish a chemical balance between the two substances, and then, using mathematical calculations, the concentration of the desired substance in the sample is calculated.
Titration is used in many chemical, medical, food and environmental industries. This method is used to determine the concentration of drugs, acids, bases, food and environmental pollutants. Also, titration is used as a valid test method in chemical laboratories.

Introduction of titration types:

Acid and base titration: Acid and base titration is one of the chemical methods used to determine the concentration of an acid or base in a sample. In this method, an acidic or basic solvent with a known concentration is used as a titrant solvent. Then, the analyzed sample is added to the titrant solvent and the pH of the titrant solvent is changed using a pH strip. Acid and base titration is used as one of the important methods in analytical chemistry and is used in many industries and laboratories.
Redox titration: Redox titration is a chemical analysis method used to determine the amount of a chemical compound using oxidation and reduction reactions. In this method, an oxidized compound and a reduced compound react with each other and a chemical balance is established between them. By using an oxidizing agent and a reducing agent, the exact amount of the compound to be determined can be calculated. This method is used to determine the amount of oxygen, sulfur, nitrate, metals, etc. Redox titration is used as one of the important methods of chemical analysis in chemical, pharmaceutical, food and biological industries.
Gas phase titration: Gas phase titration is another method in which the volume of a gas is determined using another chemical substance that is in the liquid phase. In this method, a gas is added to a liquid medium that contains a chemical that reacts with the gas. By adding a liquid to a gas, the gas is dissolved in the liquid and a chemical equilibrium is established between the gas and the liquid. Then, by adding another chemical that reacts with the gas and liquid, the chemical equilibrium is changed and the volume of the gas is calculated. Gas phase titration is used in many chemical industries, such as oil and gas, pharmaceutical and food industries.
Complexometric titration: Complexometric titration is among other methods used to determine the concentration of one or more elements in a sample. In this method, a chemical compound is combined with a complexing agent (eg, a ligand) and then titrated with another compound containing one or more metal ions. When the complexing agent binds to a metal ion, a metal-ligand complex is formed, which has a stability constant (Kf). By changing the metal ion concentration, the stability constant of the complex also changes and these changes are used as indicators to determine the metal ion concentration. This method is used to determine the concentration of heavy metals such as lead, cadmium, zinc and copper and is used in many chemical and environmental industries due to its high accuracy and titration speed.
Zeta potential titration: Zeta potential titration is a laboratory method that is used to measure the surface charge of colloidal particles and also to check the stability of these particles in electrolyte solutions. In this method, an electrode is added to the solution to measure the zeta potential, and then, using a titrator, the amount of electrolyte required to balance the surface charge of the particles is added to the solution. In this method, zeta potential is investigated as an indicator of the stability of colloidal particles in electrolyte solution. This method is used in many industries such as food, pharmaceutical and agricultural industries.

Assay titration: Assay titration is an experimental method to determine the concentration of a substance in a sample. This method is based on chemical interactions between two substances, one of which is known as titrant and the other as titer. In this method, a certain volume of titrant is added to the titrant until an equilibrium point is reached. This equilibrium point is known as titration point and titer concentration. Titration assays are usually used to determine the concentration of acids, bases, salts and other chemical compounds. This method is used for many chemical analyzes due to its high accuracy, simplicity and feasibility.

Examining the applications of titration:

Titration is one of the most important and widely used methods in analytical chemistry. This method uses a chemical compound that reacts with the desired substance and by changing its color, it provides an indicator to measure the concentration.
In the food industry, titration is used to measure the concentration of acids, bases, salts and other substances. For example, in the production of sweets, titration is us

In medical diagnostic laboratories, titration is used to measure the concentration of drugs, hormones, and other chemicals in blood, urine, and other body fluids.
In water and wastewater industries, titration is used to measure the concentration of solutes, heavy metals and other substances in water and wastewater.
In the pharmaceutical industry, titration is used to measure the concentration of drugs and other chemicals in pharmaceutical products.

Review of different titration methods:

Direct titration: Direct titration is a titration method in which the volume of the solution to be titrated is compared with the volume of the standard solution. This method is used as a quick and accurate method to determine the concentration of the solution. To perform a direct titration, first the solution to be titrated is placed in a container. Then the standard solution is slowly added to the solution until it reaches a certain level. At this point, the titration ends and the concentration of the solution is calculated.
Indirect titration: Indirect titration does not mean determining the concentration of a substance using a titration process, but using other methods such as measuring light absorption by a substance, determining the molecular weight or determining the optical spectrum of a substance. . These methods are used due to the lack of a direct titration to determine the concentration of the substance.
Reverse titration: Reverse titration or reverse titration, as a concentration determination method, is a method in which a solution with a known concentration (standard solution) is gradually added to a solution with an unknown concentration (sample solution) until an equilibrium point is reached. reach In this method, the volume of the standard solution consumed is considered as the dependent variable and the concentration of the sample solution as the independent variable.

To perform a reverse titration, we first prepare a standard solution with a known concentration and, using a pipette, put an exact volume of it into a sample solution. Then, using an indicator, the color change of the solution is used to determine the equilibrium point. In this method, the equilibrium point is the point where equilibrium is established between the standard solution and the sample solution. According to the consumed volume of the standard solution and its known concentration, the concentration of the sample solution can be calculated.
Reverse titration is used in many chemical, medical and food industries due to its high accuracy in determining the concentration of solutions.

Check the titration process:

Titration is a chemical process in which the volume of an acidic or basic solution is determined by a specific volume of a standard basic or acidic solution. The titration process generally includes the following steps:
1. Preparation of standard solution: standard solution of base or acid is prepared with precise concentration.
2. Preparation of sample solution: The sample solution is carefully measured and added to a mixer.
3. Addition of indicator: The indicator is added to the sample solution so that the color change can be seen during the titration.
4. Titration: The standard solution is slowly added to the sample solution so that the color of the indicator changes. The titration continues until the color change of the indicator reaches a constant state.
5. Calculation of concentration: Using the volume of the standard solution consumed and the volume of the sample solution, the concentration of the sample solution is calculated.
6. Repetition: The titration may be repeated to more accurately determine the concentration of the sample solution.
Note that the titration process may be different for different solutions and using different standard solutions.

Conditions required for titration:

1. Sample: The sample on which the titration is to be performed must have certain characteristics. For example, in the titration of acid and base, the acid or base must be pure and of a certain concentration.
2. Chemical compounds: To perform titration, the chemical compounds needed to produce titrant and measure the concentration of solutions must be available.
3. Solvent: For titration, the solvent used to dissolve chemical compounds must meet certain characteristics. For example, in acid-base titration, water is usually used as the solvent.
4. pH strip: To measure the pH of solutions, a pH strip is necessary.
5. Titration device: A titration device is needed to perform titration. This device includes a mixer, a buret, a pipette, a pH strip and a volume measuring device.
6. Knowledge and experience: knowledge and experience are required to perform titration. It includes knowledge about chemical compounds, solvents, pH strip and titration apparatus.