♦ For example, to prepare a 10% solution of sodium chloride, 10 g of sodium chloride can be diluted in 90 g of water. ♦ One can prepare standard solutions of the desired concentration in the laboratory by simply diluting/dissolving a carefully measured volume of either a stock solution (a concentrated laboratory reagent from which solutions can be made), or the substance itself in solid form, with a corresponding amount of water. In order to construct a calibration curve, one needs a number of solutions of which the concentration is known, which are known as standard solutions.
These properties of a liquid can be measured in the laboratory with the help of an instrument called spectrophotometer. The ability of a liquid to absorb, reflect, or transmit light varies with its concentration. Everything There is To Know About Calibration Curves Our endeavor is to help you familiarize yourself with all there is to know about calibration curves. This reasonably accurate and surprisingly simple technique is actually a vital step in detail-oriented fields of analytical chemistry, like spectrometry. A calibration curve is basically a graph that represents the response of an analytical laboratory instrument (or in simpler words, the changing value of any one measurable liquid property) with respect to various concentrations of that liquid, which is generated using experimental data. One of the most fundamental methods used to calculate the concentration of an unknown liquid is the use of a calibration curve. This law of analytical chemistry states that the relationship between the concentration of any solution and its absorbance is linear.Īccording to this law, theoretically, a calibration curve generated by observing the response of the instrument in terms of the liquid’s absorbance, for its different concentrations, looks like a straight line.