Determination of Streptomycin and Dihydro-streptomycin in Ketchup by Enzyme Linked Immuno Sorbent Assay

Rapid determination of streptomycin (SMC) together with dihydrostreptomycin (DHSMC) in ketchup by the method of enzyme linked immuno sorbent assay (ELISA) was proposed, and the testing reagents kit was prepared. By using pentanedial as cross-linking reagent to react first with SMC and then with BSA and with OVA separately, the SMC immunogen of BSA-SMC, and the coating immunogen of OVA-SMC were prepared. The SMC monoclonal antibody of SMC-mAb was prepared by using the 8 week-aged female BABL/c mousie which was immunized by the SMC immunogen. The OVA-SMC was used to coat the enzyme standard plate. Standard curve was prepared by using the values of absorbance percentage (A/A0) as ordinate, and the values of mass concentration of SMC standard solution as abscissa, giving a linear relationship in the range of 0.05 to 4.05 μg·L-1 of SMC. Detection limit (3s) was found to be 1.98 μg·kg-1. Values of recovery found were in the range of 79.4%-92.0%, and values of RSD′s (n=6) obtained within batch and among batches were all less than 10%. DHSMC reacted in the same manner as SMC, hence the result of determination was the sum of SMC and DHSMC.