Reference no: EM133359450

Multi-Component Analysis

Explore wide datasets of qualitative variables, and to measure two chemicals simultaneously and analyze their concentrations using multi-component analysis. Absorbances are additive at a specific wavelength.Two cases:

Analytes overlap considerably at the analytical wavelength
• Use least squares difference approach
• Use Excel and solver
• Find concentration combination that minimizes difference between theoretical values of A and our measured value.

1. Highlight cell H11 (the cell we want to minimize) and select Solver

2. Enter "H11" in Set Target Cell. Then select the button that says Min. Enter "D14,D15" in By Changing Cells (trial and error values)

3. Click Solve

4. Cells D14 and D15 now tell us that [Ti(IV)] = 0.670 mM and [V(V)] = 1.123 mM in the mixture
A = εxb[X] + εyb[Y] + εzb[Z] + ...
• Measure A at many wavelengths for separate analyte standards, calculate ε at each wavelength for each standard (best analysis comes from many point measurements)
• Predict Absorbance of mixture to give calculated mixed absorbance at each wavelength
• Minimize the LSD by varying the concentration of each analyte using solver.