Question

21 What major advantage does a standard addition method offer over a calibration graph for the quantitative analysis of a sample?

Answer 1

What major advantage does a standard addition method offer over a calibration graph for the quantitative analysis of a sample?

Ans:

Calibration Carve: It is a special technique, which is used for the identification as well as calculation the amount of an analyte from an unknown sample by comparing with standardized data sheet or carve. We need to prepare several sets of samples which will be calibrated against an instrument which will give a out put and after plotting the data we are supposed to get the required data.

Where as,

Standard Addition Method: Along with the unknown sample standard we have to add during the sample preparation. In this method, we need to add standard sample in different quantity in the unknown sample. E.g. 5 sample container of 20mL contain 10 mL of unknown sample in each container but standard concentration will be 1,2,3,4 and 5 respectively. And total response outcome will be addition of standard and present unknown sample. After getting the data, on plotting we suppose to get a linear data. Upon extrapolation to backward we can get the concentration of the unknown sample.

So from the process itself we can strictly identify the major advantage of standard addition method over Calibration method. As standard is present in the sample, it is expected to be a complete evaluation of the unknown sample along with minute error percentage of ±1%. Over error percentage, calibration is easy in techniques, calculation is simple and more over reputability is consistent.