The key difference between separation and purification is that separation is the conversion of a mixture of substances into two or more products or a mixture of products whereas purification is the removal of contaminants from an analyte sample.
Separation and purification are two related processes in analytical chemistry; separation can be used for purification processes.
CONTENTS
1. Overview and Key Difference
2. What is Separation
3. What is Purification
4. Side by Side Comparison – Separation vs Purification in Tabular Form
5. Summary
What is Separation?
Separation is the conversion of a mixture of substances into two or more distinct product mixtures. During a separation process, at least one of the constituents in the source mixture is concentrated in the final result. Sometimes, a separation process can completely divide the mixture into its pure components. Also, purification is a specific type of separation process where we can separate and isolate a desired component from a mixture of components. Importantly, separation of a mixture can exploit the differences in chemical and physical properties between the constituents of the mixture.
Moreover, separation processes are often classified according to the particular differences that the processes used for the achievement of the expected separated products. However, if there are no specific differences between the constituents in the mixture, we may have to use multiple operations in combination with each other to get the desired end product.
Generally, chemical elements and most of the compounds occur in the impure state in nature. Therefore, we can separate the desired elements or compounds from their source (ore) and perform a separation process before the constituents can be put into productive use. Thus, this makes the separation techniques essential for modern industry.
Figure 01: Flotation Technique – a Type of Separation
Typically, the purpose of the separation technique is analytical. But sometimes, it is preparative when we can prepare different fractions of an analyte sample for further applications. Moreover, we can perform a separation technique in small scale or in large scale (e.g. industrial scale).
What is Purification?
Purification is an analytical technique in which we can separate contaminants from a desired substance. In other words, purification is the process of rendering something pure. It is the physical separation of chemical substances of interest from contaminating substances. We can name the pure result of a successful purification process as an “isolate”.
Moreover, there are different methods of purification that we can use in chemistry depending on the purpose and application; some examples include affinity purification, filtration, centrifugation, evaporation, extraction, crystallization, recrystallization, adsorption, chromatography, smelting, refining, etc.
What is the Difference Between Separation and Purification?
Separation and purification are two related processes in analytical chemistry where separation can be used for the purification processes. The key difference between separation and purification is that separation is the conversion of a mixture of substances into two or more products or a mixture of products whereas purification is the removal of contaminants from an analyte sample. Also, separation involves techniques like chromatography, electrophoresis, flotation, extraction, etc. while purification involves affinity purification, filtration, chromatography, adsorption, extraction, etc.
The following infographic summarizes the difference between separation and purification in tabular form.
Summary – Separation vs Purification
In a nutshell, separation and purification are two related processes in analytical chemistry where separation can be used for purification processes. The key difference between separation and purification is that separation is the conversion of a mixture of substances into two or more products or a mixture of products, whereas purification is the removal of contaminants from an analyte sample.
Reference:
1. “7.6: Classifying Separation Techniques”. Libretxt., Available here.
Image Courtesy:
1. “Flotation cell” By Dhatfield – Own work (CC BY-SA 3.0) via Commons Wikimedia