Question

Difference between coprecipitation and post precipitation

Answer 1

Coprecipitation. In chemistry, coprecipitation (CPT) or co-precipitation is the carrying down by a precipitate of substances normally soluble under the conditions employed. Analogously, in medicine, coprecipitation is specifically the precipitation of an unbound "antigen along with an antigen-antibody complex".

Answer 2

Co-precipitation

• It  is the precipitation that occurs simultaneously by more than one soluble component in a single solution. Mixed crystals appear after co-precipitation.
• This impurity occurs either by adsorption, occlusion or entrapment.
• It is helpful for the separation of tracer in radioisotopes.
• Magnitude of contamination is less.

Post-precipitation

• It is the precipitation that occurs as a layer upon the already formed precipitate.
• It is a surface based contamination/impurity that occurs due to high primary adsorption and supersaturated solution.
• Magnitude of impurity is higher.