QUESTION 5 a. One potential shortcoming of Atomic Absorption Spectrometer (AAS) is chemical interference. i. Define the term chemical interference. (1 mark) ii. List three (3) ways how chemical interference can be eliminated in AAS. (3 marks) iii. Sketch atomic absorption spectrometer, indicating key parts. (4 marks) b. The content of iron in water was evaluated using AAS at Aquatech Industries Ltd, the results are as indicated in the table below. Concentration (mg/L) Absorbance 0 1 16.6 2 37.8 3 53.2 4 68.7 5 95.2 Sample 1 and 2 45.6 and 102.7 i. Determine the iron concentration in mg/L for each sample and comment on the value found for sample 2. (4 marks) ii. State two (2) differences between Atomic Absorption Spectrometer and Flame Emission Spectrometer. (2 marks) QUESTION 6 a. Differentiate between the following terms as use in chromatography. i. Normal phase and Reverse phase. ii. Isocratic elution and gradient elution. (2 marks) (2 marks) b. The flow diagram below represents HPLC system. Study it and answer the questions that follow.