production of selected secondary metabolites in transformed ...

F i
90
70
50
30
10
-10
-30
Zephyramin
Septonex Ajatin
DDAB
Triton
SDS
-50
0 0,002 0,004 0,006 0,008 0,01 0,012 0,014 0,016
Fig.4.: Surfactants influence on Ga-HQS complex at pH 3. Septonex, Zephyramine, Ajatin,
SDS – mol.dm -3 , CTAC (Hexadecyl trimethyl ammonium chloride)– c/4 (mol.dm -3 ),
DDAB (Didodecyldimethyl ammonium bromide) – c/5 (mol.dm -3 ), Triton X-100 –
c/4.10 -5 (ppm), Brij – c/15 (mol.dm -3 ).
Critical micellar concentrations are highlighted by the fulfilled marks.
The nature of the complex strongly depends on the pH. The molar ratio of Me to QSA in
the binary complex determined by the continuum variations method is 1:1 in acidic range and
1:3 in alkalic range (Fig.5). In the presence of cationic surfactant Zephyramine, the molar
ratio of ternary complex was found to be always 1:3 (Fig.5).
F i
100
80
60
40
20
0
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
x L
1
2
3
c
80
60
40
20
CTAC
Brij
a 100
b
F i
0
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
Fig.5.: (a) Continuum variations of Al-HQS complex at pH 4. 1-c0= 1,1.10 -4 M, 2- c0= 5,6.10 -5 M,
3-5,6.10 -5 M, 0,0012M Zephyramine
(b) Continuum variations of In-HQS complex. 1-c0= 3,5.10 -5 M, pH8, 2- c0= 1,8.10 -5 M,
pH8, 3-1,8.10 -5 M, 0,0012M Zephyramine, pH8, 4- c0= 1,8.10 -5 M, pH4
Finally, the improved method with enhanced sensitivity by the presence of cationic
surfactant Zephyramine was optimized with concentration of Zephyramine 0,0012M and five
times excess of QSA to highest molar concentration of Me. Optimal pH is 4 for Al, 3 for Ga
and 8 for In.
Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006
Sekce DSP 2006, strana 246
x L
1
4
2
3