You are a supervisor in a laboratory which focuses on the determination of trace and ultra-trace levels of toxic substances in water samples. Usually, for the determination of cadmium in water, a Graphite Furnace Atomic Absorption Spectrophotometer (GFAAS) is used but, since it was down for repairs, one of the technicians that you supervise decided to use the operable Flame AAS instrument. After establishing that absorbance varied linearly with the amount of cadmium, the following absorbance value data (for 5 replicate measurements) were obtained for a blank and for a sample submitted for analysis: Blank: 0.001,0.002,0.003,0.001 (average value =0.0018, standard deviation =0.0008 ) Sample: 0.004,0.003,0.004,0.005,0.004 (average value =0.0040, standard deviation =0.0007 ) (a) Based on the average absorbance values, the technician reported that the water sample contained 100ppb (parts per billion) cadmium (5 ppb cadmiumilis the maximum cadmium level allowed in drinking waterl). As the lab supervisor, you are ultimately responsible for the analysis results that are reported. Should this result be reported? EXPLAIN. (NOTE: your response should be based on the above data. HINT: does the signal-to-noise of your technician's measurements permit you to make the claim above?) (15 points) (b) You wonder if this measurement is even worth doing, so you decide to do an experiment. You prepare and measure a 1000ppb cadmium standard, which, before subtraction of the blank, gives an absorbance reading of 0.020. Based on this measurement, what is the detection limit (ppb) of cadmium for this instrument (HINT: Assume a linear relationship between the absorbance signal and the concentration) (10 points)