A calibration plot is essential for carrying out quantitative analytical determinations. It is possible to carry out a single determination without a calibration plot as in titrimetry or gravimetry. However, when a number of quantitative determinations are required using common instrument analysis methods the variables affecting your analysis get multiplied and it becomes necessary to construct a calibration plot over a range of concentrations to accommodate influence of such variables.
Ideally a calibration plot originates at the origin or the intersection point of the recorded parameter axis and the concentration axis and emerges as a straight line with increase in concentration. In simple words it means that when concentration is zero the response is also zero and increases in a mathematical relation with increase in concentration. In real situations, calibration plots show deviations from this ideal behavior after a range of concentrations. Today’s lab bytes covers the important considerations that need to be kept in mind in construction and use of calibration plots.