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

1) While doing measurement we use maximum wavelength to maximize the signal to noise ratio. biggest signal, thus gives a high ratio compared to the noise.
Even a small change in wavelenth can give maximum change in absorption is another reason.

3) Limit of detection (LOD) and Limit of quantitaion (LOQ) have inyention to find smallest concentartion of an analyte that can be detected.

LOD = (3.3 * Std Deviation of blank) / Slope of regrerssion line

LOQ = (10 * Std Deviation of blank) / Slope of regrerssion line