You have developed a new spectrophotonetric method for estimation of Fe(II) in a solution using new reagent 'R. How will you validate your method for 'Accuracy and Precision?
To validate the accuracy and precision of the spectrophotometric method for estimation of Fe(II) using reagent 'R', the following steps can be taken:
1. Calibration curve: Prepare a series of standard solutions containing known concentrations of Fe(II) and analyze them using the spectrophotometric method with reagent 'R'. Construct a calibration curve by plotting the absorbance values against the concentrations of Fe(II). The linearity of the calibration curve will indicate the accuracy of the method.
2. Recovery test: Perform a recovery test by spiking a known amount of Fe(II) into a sample solution and analyzing it using the spectrophotometric method. Calculate the recovery percentage by comparing the measured concentration with the expected concentration. A recovery percentage close to 100% indicates the accuracy of the method.
3. Precision test: Perform replicate analyses of a sample solution containing a known concentration of Fe(II) using the spectrophotometric method. Calculate the % RSD (relative standard deviation) of the replicate measurements to assess the precision of the method.
4. Interference study: Evaluate the method's selectivity and specificity by testing the interference of other ions or compounds that may be present in the sample solution. This can be done by spiking interfering substances and analyzing the solutions to determine if they affect the accuracy and precision of the Fe(II) estimation.
5. Comparison with reference method: Compare the results obtained from the spectrophotometric method using reagent 'R' with those from a reference method (such as titration or atomic absorption spectroscopy) to validate the accuracy and precision of the new method.
By performing these validation tests, the accuracy and precision of the spectrophotometric method for estimation of Fe(II) using reagent 'R' can be thoroughly evaluated and confirmed.