Chemometrics Quiz: No outside resources allowed; please show all work to receive any credit

Spreadsheet with Data Tables

1.  In an advanced instrumental analysis experiment you obtained the calibration data listed in the table below; subsequent analysis of a river water sample gave a signal of 27.5. Conduct a second order calibration, write out the calibration equation you determined, state the fraction of variability described by your equation, plot the data along with the predicted concentrations, and then calculate the river sample concentration.

2. The gold content of a concentrated sea-water sample was determined by atomic absorption spectrometry using standard addition with the results in the table below.  Estimate the concentration of the gold in the concentrated seawater.
 
ng Au added 
per mL of concentrated sample
Absorbance
0
0.257
10
0.314
20
0.364
30
0.413
40
0.468
50
0.528
60
0.574
70
0.635

3.  From your results in problem 2, use propagation of error to calculate the uncertainty in your calculated Au concentration in units of ng/mL.