Method Validation of Contact and Immersion TLC-bioautography for Determination of Streptomycin Sulfate in Shrimp

Objectives: Contact and immersion thin layer chromatography (TLC)-bioautography were developed for identification and quantification of streptomycin sulfate in shrimp. Materials and Methods: TLC of streptomycin sulfate standard solution was carried out using silica gel F-254 and 7.5% of KH2PO4 solution as stationary and mobile phase, respectively. Results: The retardation factor of the streptomycin sulfate standard was 0.51 and the selectivity of streptomycin sulfate was 4.1 with the presence of kanamycin sulfate in the shrimp. The bioautography was performed with Escherichia coli ATCC 8739 as a test bacterium. The limit of detection of streptomycin sulfate obtained by contact and immersion TLC-bioautography was 0.24 mu g and 0.16 mu g, respectively. Both methods showed good linearity with an r value greater than 0.999 and a Vxo value less than 2%. The accuracy of the contact and immersion TLC-bioautography was tested by standard addition method and the obtained percentage recovery was 86.93 +/- 1.60% and 96.42 +/- 0.65%, respectively. The coefficient of variation of the contact and immersion TLC-bioautography was 2.39 +/- 1.79% and 0.53 +/- 0.17%, respectively. Conclusion: The immersion TLC-bioautography was more sensitive with better recovery than the contact TLC-bioautography. In addition, immersion TLC-bioautography was successfully employed for determination of streptomycin sulfate in shrimp.