Question

1. The measurement of the absorbance was done at the maximum wavelength. Please provide two reasons why this wavelength is selected.

2. In a calibration curve, how is the sensitivity of the method defined?

3. Provide two different ways to calculate the LOD and LOQ.

4. In a statistical analysis, what is the minimum sample size requirement to apply a test? Is there any maximum? Please provide examples for different tests (min. of two examples).

Answer 1

Ans 1.

Ideally the measurement of absorbance is done on the wavelength that shows maximum difference between peak and background. But while measuring absorbance if it is recorded on the peak , then a slight error of 1- 2 nm will not affect the results. But if you choose to measure it on the either side of peak, a small error of 1 nm would be magnified and the measurements will be poorly reproducible.

And secondly it gives the value of maximum absorbance by the compound only on maximum wavelength which helps determining the concentration of unknown sample.