Question

1) Why do we use wavelength at max to generate the calibration curve?

2) Explain the purpose of the blank? In general, what should the blank contain?

Answer 1

1) Thre are two reasons to use wavelength at maximum:

• The sensitivity of the analysis is great at maximum absorbance; that is, det the ,maximum response for a given concentration of analyte.
• The curve is relatively flat at the maximum, so there is little variation in absorbance if the monochromator drifts a little or it the width of the transmitted band changes slightly.

2) The purpose of the blank is to known the interferences. Blank contains all reagents, but with analyte replaced by distilled water. Substract the blank absorbance from the absorbance of sample amd standards before doing any calculations.