2. Introducti on Objectiv e Experimenta l section Results and discussion Conclusio ns

4. Sulfonamides are drugs with bacteriostatic activity used as feed additives and treating infections

5. Toxicology Advantages Low cost ● Low cost Excellent activity against bacterial diseases ● Excellent activity against bacterial diseases Growth promoters in food animals ● Growth promoters in food animals Cancer ● Cancer Hypersensitiv ● Hypersensitivity

8. Switch From HPLC to UFLC

9. UFLC Increased resolution Increased sensitivity Reduced diffusion path High flow rate

10. Easily measurable signal Extreme sensitivity Fast detection High selectivity Why ECD?

12. High electrical conductivity High mechanical strength Low manufacturing cost

13. Introducti on Objectiv e Experimen tal Results and discussion Conclusio ns

15. Introducti on Objectiv e Experimental section Results and discussion Conclusio ns

17. spraying high voltage

18. Cyclic Voltammetric investigation Cyclic Voltammetric investigation Potential range : 0.7-1.5 V Reference Electrode : Ag/AgCl Counter Electrode : Pt wire SA Concentration : 50 ppm Electrolyte : PBS (pH 3) Scan rate : 0.05 V/sec Characterization of electrode Characterization of graphene-modified screen-printed carbon electrode Characterization of graphene-modified screen-printed carbon e ee electrode Batch Condition Batch Condition

19. Inertsil C4 column 150mm X 4.6 nm i.d; partical size, 5 µm

20. Introducti on Objectiv e Experimen tal Results and discussion Conclusio ns

23. SMM SDM SG SDX SMX SSZ

24. SDZ SMZ

25. SG SD Z SM Z SM M SD X SM X SS Z SD M

26. Chromatogram of eight SAs 10 ppm in potassium hydrogen phosphate solution pH 3 Chromatogram of eight SAs 10 ppm in potassium hydrogen phosphate solution pH 4 Chromatogram of eight SAs 10 ppm in potassium hydrogen phosphate solution pH 5

27. Chromatogram of eight SAs 10 ppm in potassium hydrogen phosphate solution pH 6 Chromatogram of eight SAs 10 ppm in potassium hydrogen phosphate solution pH 7 Chromatogram of eight SAs 10 ppm in potassium hydrogen phosphate solution pH 3

28. ColumnInertsil C4 (150 x 4.6 mm) Mobile phasePhosphate buffer(pH3): ACN: EtOH Flow rate1.5 mL/min Injection Volume30 µL Temperature25 ºC DetectorAmperometric detection at 1.4 V SG SDZ SMZ SMM SDXSMX SSZ SDM

29. y = 29.236x + 28.891 R 2 = 0.9954

31. Analyt e Linearity (ppm) R2R2 LOD (ppb) LOQ (ppb) SG0.01-100.99341.1623.336 SDZ0.01-100.99131.6015.337 SMZ0.01-100.99222.9009.667 SMM0.01-100.99542.4678.224 SDX0.01-100.99122.9959.983 SMX0.01-100.99202.5138.376 SSZ0.01-100.99513.28710.957 SDM0.01-100.99496.12720.425

35. 35