Atomic absorption spectroscopy was used to determine the amount of aluminum in a sample of sunscreen. A blank solution was measu
red seven times to determine the detection and quantitation limits of the spectrometer. The blank readings were: 0.0159 , 0.0081 , 0.0095 , 0.0109 , 0.0090 , 0.0114 , and 0.0090 AU. Determine the signal at the detection limit and the signal at the limit of quantitation for this method.
Detection limit (LOD) is defined as the lowest signal which, with a stated probability, can be distinguished from a suitable blank signal. In the same way, quantification limit (LOQ) is defined as the lowest analyte concentration that can be quantitatively detected with a stated accuracy and precision.
There are many formulas but the most used are:
LOD = X + 3σ
LOQ = X + 10σ
Where X is average and σ is standard desvation
For the blanks readings the average X is 0,0105 and σ is 0,0024
