Question

What is the minimum number of samples that could make a standard line on the calibration curve and why do we use many samples

Answer 1

Calibration curve :- Calibration curves are used to predict the concentration of an unknown solution which to be analysed (analyte). It can be used to limit of detection and limit of quantitation. This is also referred as standard curve in spectrometry/Spectroscopy

The minimum number of sample solutions to be taken are 4. The curve basically depends on Beer- Lamberts law. The graph can be drawn between absorption and concentration. Astraight line is observed. If the curve is not linear then a few points are required to establish the curve( non-linear curve obatined at high absorbence values). This curve is obatained from the series of solution made from unknown sample. When it is kept into the sample inlet position in the istrument it gives the absorbance.

Making of number of solutions is a dilution process. These solutions made from the initial solution. The next dilution continuos with previous solution. Generally the absorbance range between 0.1 to 0.4. But there is a disadavantage in preparing solutions. If the initial solution carried out perfectly then nothing will be happen. But in case of any mistakes in preparation of intial solution that gives different concentration and leads to error in absorbance.