There is a suggestion that semicarbazide (SEM), the marker for the illegal veterinary nitrofurazone (NFZ), can naturally occur in some crustaceans. There were increasing occurrences that SEM had been found in Macrobrachium Nipponese (M. Nipponese) prawns during the routine quality controls testing for aquatic food in China since 2008. To ascertain the presence and source of SEM, samples were collected from different resources (i.e., aquatic product markets, natural waters, aquaculture farms) for qualitative and quantitative analysis of SEM. We incubated M. Nipponese larvae in the laboratory under control. The result showed that SEM was detected out in all the samples analyzed, including the wild-caught samples, and it presenting a regular content relationship among different parts of prawns (i.e., the shell > head > muscle). This relationship was unrelated to samples resources. In addition, a natural increase of SEM was observed after the larvae metamorphosing into postlarvae. These findings in M. Nipponense prawns provided new evidences for further confirming and researching the natural occurrence of SEM.
Experimental
Reagents and ChemicalsMethanol, ethyl acetate, hexane (n-hexane, 95%) all were HPLC grade (J. T. Baker). 2-Nitrobenzaldehyde (2-NBA, 98%) was bought from Alfa Aesar (Tianjin, China). Ammonium acetate (HPLC, 99.0%) was from Sigma-Aldrich (St.Louis.MO.USA). Water (18MΩ) was International Symposium on Material, Energy and Environment Engineering (ISM3E 2015)