Abstract: The derivatization conditions for the determination of semicarbazide by enzyme-linked immunosorbent assay (ELISA) were optimized using combination of one-factor-at-a-time method and response surface methodology with Box- Behnken design. The independent variables were volume and concentration of derivatization agent, derivatization temperature and time and the recovery of semicarbazide was used as response variable. The linear range of ELISA was 0.13-10.51 ng/mL and the 50% inhibitory concentration (IC50) value was 1.17 ng/mL. The optimal derivatization conditions were determined as follows: using 415 μL of 15 mmol/L derivatization agent and derivative at 57 ℃ for 50 min. Under these conditions, the recovery of semicarbazide was in the range of 98.57%-103.76%. The cross-reactivity value of the derivatization product was 7.63% with furacilin and lower than 0.17% with its structural and functional analogues. The recoveries in spiked negative samples ranged from 93.45% to 103.21%. The intra-assay and inter-assay coefficients of variation wer e 1.86%-6.15% and 3.88%-8.84%, respectively. The derivatization conditions were highly efficient and the ELISA method was sensitive, accurate, and suitable for the fast screening of semicarbazidee in animal-derived foods.

Key words: semicarbazide (SEM), derivatization conditions, response surface methodology, animal-derived foods, enzyme-linked immunosorbent assay (ELISA)