To determine the Cadmium content of a tailing pond. A Systematic Sample Plan was collected and the 8 samples were combined into one representative bulk sample and aliquots were extracted for analysis in triplicate. The following data have been generated:

Concentration in g/l	Absorbance
0.0	0.005
0.5	0.054
1.0	0.113
5.0	0.520
-	-
Sample Replicate 1	0.043
Sample Replicate 2	0.040
Sample Replicate 3	0.045

The mean of the Cadmium is 0.35g/L and the Standard Deviation for Cadmium is 0.026. Therefore calculate:

1. Calculate the Detection Limit for the analysis.
2. Using a 100g/L Cadmium standard, describe in detail how Spike Recovery can be used to validate the Method.