Atomic absorption spectroscopy was used to determine the amount of aluminum in a sample of sunscreen. a standard solution of 1.00 ng al /l was prepared and measured seven times to determine the detection and quantitation limits of the spectrometer. the standard measurements were: 0.79, 0.89, 1.35 , 1.05 , 0.90 , 1.17 , and 0.97 ng al /l. calculate the detection and quantitation limits for this instrument.