Determination of oxytetracycline residue in shrimp using a portable time-resolved analyzer and HPLC–MS/MS validation

Abstract

Oxytetracycline residue in shrimp muscle was determined using a portable time-resolved analyzer. After extraction in EDTA-metaphosphoric acid and filtration, the analyte was cleaned up using hydrophilic-lipophilic balance cartridges. Europium-sensitized luminescence (ESL) was measured at λex = 385 nm and λem = 620 nm. Recoveries were 80.3 and 79.7% at 100 ng g−1 and 2 μg g−1, respectively. The signal intensity was linear (r2 ≥ 0.996) in each decade in the 5–5,000 ng g−1 range. Averaged relative standard deviation was ~2% and limit of detection was 8.3 ng g−1. This instrument-method combination enabled sensitive in-situ quantification of OTC residue in shrimp. The ESL results were validated by HPLC–MS/MS.