1. Fabrication of Bismuth-Chitosan modified Glassy
Carbon Electrode and its application in
measurement of Tartrazine
in Food and Drug sample
Supervisor: Dr Karim Asadpour-Zeynali
Advisor: Dr Esmaeel Alipour
Presented by: Mozhdeh Aleshi
Master thesis presentation in Analytical Chemistry

2. Modified Electrodes
 Introduction : Synthetic Colorants: Tartrazine
Measurement of Tartrazine
 Experimental
Results and Discussions
Conclusions
2
Contents

3.  Modified Electrodes: properties Bismuth-modified electrode
• Modification methods
1. Ex-situ plating
2. In-situ plating
3. Bi2O3
3
Introduction
Properties
Wide potential range
Low background
Insensitive to oxygen
Non-toxicity

4. 4
Introduction
A B
KBr role in modification process by ex-situ method

5. 5
Introduction
deacetylation
Chitosan properties : non-toxic, hydrophilic,…
Chitosan:

6. 6
Introduction
Food Additives
Colorants
Natural
Synthetic
preservatives
Anti-oxidants
pH regulators
Azo dyes
Color
Index(C.I)
FD & C

7. Tartrazine
Also known as : E102 / C.I.19140 / FD&C yellow acid 5
‫ل‬‫جدو‬1-1‫مختلف‬ ‫غذایی‬‫محصوالت‬ ‫در‬‫ازین‬‫ر‬‫تارتا‬ ‫از‬ ‫استفاده‬‫مجاز‬‫ان‬‫ز‬‫می‬
7

8. •Spectrophotometery
•HPLC
•Electrochemical
Measurement of Tartrazine
8

9. •working electrode: Bi-Chit GCE
•auxiliary electrode: Pt Electrode
•Reference: SCE(Saturated Calomel Electrode)
Optimum conditions :
ex-situ method, 0.18mg/ml Bi, KBr 0.05 mg/ml, pH=4.5, acetate 0.1M, - 0.75
V, 200s (stirring solution)
Techniques:
Differential pulse voltammetry
Cyclic Voltammetry
Hydrodynamic Amperometery
9
Experimental

10. Results &
Discussions
10

11. 11
Electrochemical behavior of Tartrazine

12. • pH
12
:Optimization Of Electrode modifying parameters
0
0.5
1
1.5
2
2.5
3
3.5
4
1 2 3 4 4.5 5
ip(µA)
pH
pH=4.5
•Bismuth concentration
0
0.5
1
1.5
2
2.5
3
3.5
4
0.04 0.1 0.15 0.18 0.2 0.24 0.28 0.3 0.35
i/µA
C(mg/ml)
C=0.18 mg/ml

13. Preconcentration timePreconcentration potential
Eapp= -0.75 V.vs SCE t =200s
0
0.5
1
1.5
2
2.5
3
3.5
0.6 0.7 0.75 0.8 0.85 0.9 0.95 1
i/µA
-E/V
0
0.5
1
1.5
2
2.5
3
3.5
100 120 140 160 200 220 240
ip/µA
t/s
13

14. 14
Characterization of Bi-Chit modified GCE

15. 15
EDAX report of Bi-Chit modified GCE

16. 16
2e− + 2H+ + (R–N=N–R1) → (R–NH–NH–R1)
(1)
2e− + 2H+ + (R–NH–NH–R1) → (R–NH2) + (R1–NH2) (2)
pH

17. Buffer concentration
17
C= 0.3M

18. 18
Effect of Scan rate

19. Choronoamperometery
n = 2, F = 96487, A= 0.0314 cm2
7.56 D = 4.89 × 10-6 cm2s-1
19

20. Effect of Tartrazine’s concentration
20

21. Calibration carve(DPV method)
y = 10.59x + 1.144
R² = 0.993
y = 5.896x + 5.565
R² = 0.995
0
5
10
15
20
25
0 0.5 1 1.5 2 2.5 3
i(µA)
C(mM)
XLOD = 3 Sb/b XLOD = 16 µM or 8.550 µg/ml
21

22. Hydrodynamic Amperometery
XLOD = 3 Sb/b XLOD =12.098µM or 6.464 µg/ml
22

23. •Drug sample: bisacodyle tablets
Analytical determination of TT in Real samples
23
•Food sample: Eminem(yellow)

24. 24
RSD%Amount of TT per tablet/ eminemAnalysis No.Sample
1.157
0.52001
Bisacodyle 0.52152
0.51303
1.147
1.1901
Eminem(yellow) 1.1442
1.1203
•0.515mg/per tablet
•1.13 mg/per eminem

25. Recovery%Cspike/mMĈspike/mMAnalysis No.Sample
1020.0510.051
Bisacodyle
920.0460.052
960.0480.053
97.060.03880.041
Eminem
101.680.04040.042
91.1250.03640.043
25
Investigation the accuracy of proposed method

26. • The proposed method for measurement of Tartrazine is simple, inexpensive and
practical.
•The modified Electrode indicated better electrocatalytic reactivity Towards Tartrazine in
comparison to Glassy carbon Electrode.
•The Bismuth-Chit Glassy carbon Electrode was successfully used for determination of
Tartrazine in real samples.
26
Conclusions

27. • The proposed electrode can be used for determination and measurement of other
synthetic colorants such as sunset yellow,carmoisin,quinoline yellow.
•Application of proposed modified electrode for measurement of some pharmaceutical
compounds
•Application of Chitosan-modified Electrode for further experiments
27
Suggestions

28. 28