Zborník príspevkov z vedeckej konferencie - Department of ...

elative
area
15
10
5
-1,68 -1,00
0,00 1,00
sodium 1,00
1,68
1,68
chloride
0,00
-1,68
-1,00
volume
Figure 4. Response surface plot for the solvent extraction volume vs. the salt effect for the total relative peak area
(extraction time was 25 min).
Table 3 The values of coefficients of the second-order polynomial equation from the CCD.
Parameter
Value
Design Expert NCSS
e (Intercept) 11.62 11.61
a1 (time) 1.79 1.78
a2 ns ns
b1 (volume) -2.62 -2.60
b2 ns ns
c1 (salt) -1.52 -1.50
c2 -1.41 ns
d12 (time · volume) 1.22 1.22
d13 (time · salt) ns ns
d23 (volume · salt) ns ns
R 2 0.8807 0.8884
ns-not significant
It can be seen that both the programs calculated almost the same model, but NCSS gave slightly higher value of R 2 .
As can be seen on Figs.2-4 it is not possible to localize visually the optimal responses on the three-dimensional (two
parameters and one response) representations of the four-dimensional (three parameters and one response) mathematical
model, therefore only a mathematical approach could be applied for that goal.
Zborník príspevkov
z 18. medzinárodnej vedeckej konferencie
"Analytické metódy a zdravie loveka", ISBN 978-80-969435-7-9
- 97 -
hotel Falkensteiner, Bratislava
11. - 14. 10. 2010