| Independent |
Actual (Coded) levels |
| Variables (ml) |
Negative (-0.5) |
Zero (0) |
Positive (+0.5) |
Finer to Finest Coded |
| Methanol
(right sided |
6.0 |
6.5 |
7.0 |
A |
| Chloroform
(left-sided) |
4.0 |
3.5 |
3.0 |
B |
| Ratio A: B
(Two-sided) |
1.0 |
1.5 |
2.0 |
C |
| Dependant |
Constraints |
| Y1 = Absorbance |
0.277≤Y1≥0.318 |
| Central Composite; independent Design |
| Runs-Code |
Variables |
| Independent |
Response (Y) |
| A |
B |
C |
Observed |
Predicted |
| |
0 |
0 |
+0.5 |
0.318 |
0.288 |
| |
+0.5 |
+0.5 |
+0.5 |
0.298 |
0.312 |
| |
+0.5 |
-0.5 |
-0.5 |
0.312 |
0.277 |
| |
+0.5 |
-0.5 |
+0.5 |
0.297 |
0.298 |
| |
+0.5 |
+0.5 |
+0.5 |
0.296 |
0.291 |
| |
0 |
0 |
-0.5 |
0.316 |
0.296 |
| |
0 |
0 |
0 |
0.295 |
0.295 |
| |
0 |
0 |
0 |
0.291 |
0.297 |
| |
-0.5 |
+0.5 |
-0.5 |
0.277 |
0.296 |
| |
+0.5 |
0 |
0 |
0.285 |
0.285 |
| |
0 |
+0.5 |
0 |
0.287 |
0.290 |
| |
-0.5 |
-0.5 |
+0.5 |
0.291 |
0.286 |
| |
0 |
0 |
0 |
0.297 |
0.316 |
| |
-0.5 |
+0.5 |
+0.5 |
0.296 |
0.318 |
| |
-0.5 |
-0.5 |
-0.5 |
0.289 |
0.295 |
| |
0 |
0 |
0 |
0.298 |
0.295 |
| |
0 |
0 |
0 |
0.291 |
0.294 |
| |
0 |
0 |
0 |
0.295 |
0.294 |
| |
0 |
0 |
0 |
0.296 |
0.295 |
| |
0 |
-0.5 |
0 |
0.296 |
0.295 |
| “Finer to Finest” designed model equation |
| Term |
Model |
A |
B |
C |
AB |
AC |
BC |
A2 |
B2 |
C2 |
Lack of Fit |
| Fvalue |
217.1 |
350.0 |
85.9 |
3.94 |
8.76 |
197.7 |
123.2 |
554.5 |
92.4 |
1141.2 |
0.90 |
| Significant |
|
to |
|
Non-significant |
| pvalue; Prob.>F |
<0.0001 |
0.075 |
0.014 |
< 0.0001 |
0.5204 |
| R2 |
R-Square |
Adjusted |
Predicted |
SD |
Mean |
% CV |
| Values |
0.9949 |
0.9903 |
0.9573 |
0.0095 |
0.30 |
0.32 |
| "Prob > F" values less than 0.0500 indicate model terms are significant and greater than 0.1000 indicate the model terms are not significant. |
|
