How to perform a calibration

What is the aim of the experiment?
To establish the existing relationship between the measurement result and the quantity (or concentration).


Several types of calibration according to the measurement method: external, internal, standard additions. This sheet will present external calibration in further detail.
What is its purpose?
To estimate the amount (or concentration) of a target compound (molecule/ion/atom) in a sample.
Illustration of a graph, with an abscissa "Measurement" and an ordinate "Quantity or concentration". It shows an increasing and constant straight line, having for origin the point 0.
Practical constraints
Having a standard available (target compound in the case of external calibration or standard additions, similar compound if internal calibration).
Having access to the measuring device (spectrophotometer, HPLC-UV, or other depending on the intended analysis).
Stay within the linear range of the instrument, if possible.
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