Hplc

HPLC
A flow scheme for HPLC

Firstly, ensure that there is fitted filtered solvent in the reservoir. After that, pressurize the column and bedevil the solvent selector on the inlet manifold at the front of the pump to the running solvent. Then, switch on the agent to the pump and slowly increase the flow rate. Lastly, switch on the U.V. detector and the processing unit and display

Injection of the standard
Injection of the sample is entirely automated. This can be done because of the high pressures (up to cd atmospheres) in the HPLC tube.

Retention time
The time taken for a extra compound to travel with the column to the detector is cognize as its memory time. This time is measured from the time at which the sample is injected to the point at which the display shows a utmost peak height for that compound.
Different compounds micturate different retention times. For a particular compound, the retention time will interchange depending on:
?the pressure used (because that affects the flow rate of the solvent);
?the temperament of the stationary phase (not only what material it is made of, just also particle size);
?the exact composition of the solvent;
?the temperature of the column.




If you atomic number 18 using retention time as a elan of identifying compounds then above conditions have to be carefully controlled.
The detector
there are several ways of detecting when a internality has passed through the column. A common method is using ultra-violet absorption. This is because galore(postnominal) organic compounds adopt UV light of various wavelengths. If you have a gleam of UV light shining through the stream of liquid coming out of the column, and a UV detector on the opposite side of the stream, you can protrude a direct reading of how much of the light is absorbed.
The come in of light absorbed will depend on the amount of a particular compound that is passing through the beam at the time.

You might wonder why the solvents used dont absorb UV light. They do! But different...If you want to get a full essay, order it on our website: Orderessay



If you want to get a full essay, wisit our page: write my essay .