A New Method Based on Time-Resolved Fluoroimmunoassay for the Detection of Streptomycin in Milk

Abstract

Streptomycin (STR), used extensively in the treatment of bovine mastitis, may cause damage such as ototoxicity, allergic reaction, and increasing bacterial resistance to consumers on account of remnant in milk. A time-resolved fluoroimmunoassay (TRFIA) was developed to quantify STR for the first time to ensure food safety. Using secondary antibody labeled with europium (Eu3+) chelate as a tracer, the proposed TRFIA showed that the linear working range was 0.32–5.0 ng/mL under the optimal conditions. Milk samples were deproteinized by trichloroacetic acid and the limit of detection of STR in milk was 1.8 μg/kg. The recoveries of milk samples fortified with 4.0, 20, and 40 μg/kg of STR ranged from 86.2 to 96.3% with relative standard deviations less than 11%. Results of TRFIA for the authentic samples were coincided with those of UHPLC-MS/MS analyses. This study confirmed that the established TRFIA was sensitive as well as reliable and could be an alternative method to monitor STR residue in milk.