Determination of Semicarbazide in Foodstuffs by HPLC with Fluorescence Detection Using 2-Formylphenylboronic Acid as Derivatization Reagent

Semicarbazide (SEM), a widespread toxic food contaminant, is a stable metabolite of antibiotic nitrofurazone and widely found in some foodstuffs, such as shrimp or bread. A simple and sensitive method was developed for the determination of SEM by high-performance liquid chromatography with fluorescence detection. SEM can be labeled by 2-formylphenylboronic acid (FPBA) within 7 min at room temperature. The FPBA-SEM derivative was identified with electrospray ionization mass spectrometer in positive mode. It was found that the MS mainly gave [M + H]+ at m/z 189.8, and MS/MS gave a high abundance of a fragment ion at m/z 146.9. The derivative was completely separated on a reversed-phase Eclipse XDB-C18 column within 5 min, and excellent selectivity was obtained with fluorescence detection at specific excitation and emission wavelengths (λex = 265 and λem = 320 nm). The new method showed the lower limit of detection of 0.36 μg L−1 and the limit of quantitation of 1.17 μg L−1. Linearity with correlation coefficient of 0.995 and satisfactory accuracy ranging from 94.42 to 106.78% were obtained. This proposed method was successfully applied to determination of SEM in bread and shrimp. The developed method should have a powerful potential for the rapid determination of trace SEM in foodstuffs.