Background: Process description of downstream processing
Liquid chromatography is the most important part of the purification process and provides a broad range of physical downstream processing methods for separating complex mixtures of substances.
The components to be separated are divided into two phases:
The stationary phase in a column and the mobile phase, which flows through the stationary packing (here, liquid).
How does chromatography work?
A mixture of various components of a liquid/gas enter a process of process chromatography. The goal is to purify the mixture (downstream processing). The various separating and chromatography solutions are pumped through the system at various speeds. The interaction between the stationary and mobile phases in the system varies in intensity, causing the mixture of substances to separate. The lower the affinity of a molecule for the stationary phase is, the shorter the time in a chromatography column is, and vice versa.
Why is chromatography so special and important?
The chemical and bioprocess industries have the need to separate one product from a complex mixture and to eliminate impurities. This is an important step in the entire processing chain (downstream processing / cleaning) to produce a product with the required level of purity. Today there exists a broad range of methods that the industry can use to achieve these goals. For many reasons, chromatography is a very special and selective separation method that has been used for decades—primarily in the area of production. First, it can separate complex mixtures with great precision. Even very complicated molecules such as proteins, for instance, can be carefully separated from each other using chromatography. This way, basically any soluble or volatile substance can be purified if the correct adsorbents, carrier fluids / mobile phases are used and provided that process parameters are adapted and monitored (temperature, pH value, flow velocity, conductivity and much more).
Downstream processing is perfect for separating or purifying sensitive products from the pharmaceutical sector specifically.
