Study On Detection Method And Source Of Semicarbazide In Cultured Shrimp

Semicarbazide(SEM)is used as a metabolic marker to indicate the use of the antibiotic furacillin,and it can also be detected in non-furacillin sources.This study reviews and analysis the aquatic crustaceans and products of SEM of toxic,pathway and the detection method,to control the pollution of SEM in shellfish aquatic products,put forward several proposals to set up a breeding shrimp in semicarbazide ultra high performance liquid chromatography-tandem mass spectrometry detection method in the experiment,using this method to research residual status quo of farmed shrimp in SEM,according to the SEM distribution change law of SEM analysis content related influence factors,and preliminary exploration both in protein and amino acid farmed shrimp in the origin mechanism of SEM,A high performance liquid chromatography(HPLC)method for the determination of furacillin drug residues in shrimp using 5-nitro2-furfural as a specific indicator was established to eliminate the false positive interference of furacillin,in order to objectively monitor the use of furacillin in crustacean aquatic products.(1)Based on the national standard of the Ministry of Agriculture(Announce No.783-1-2006),a method for the rapid determination of nitrofuracilin metabolite semicarbazide in cultured shrimp by microwave-assisted derivatization combined with ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)was established to optimize the working conditions of the instrument and the method of sample pretreatment.After hydrochloric acid hydrolysis,microwave-assisted derivatization of2-nitrobenzaldehyde,extraction with ethyl acetate,purification and purification,the SEM content was detected by ultra-performance liquid chromatography-tandem mass spectrometry,and the internal standard method was used for quantification.The linear range of the mass concentration of semicarbazone was 0.5?100 ?g/L,the correlation coefficient was 0.9996-0.9999,and the detection limit was 0.20 ?g/kg.The relative standard deviations of the results were 3.06%?6.56%,and the recoveries were91.4%?103.6%.This method has the advantages of short detection time,low detection limit,good accuracy and precision,and can be used for the detection of SEM in shrimp.(2)The present situation of the residue of semicarbazone in cultured shrimp of different varieties was investigated,and the distribution law of SEM and the influencing factors of the change of SEM content were compared and analyzed.The established UPLC-MS/MS method was used to detect the SEM content in the muscle and shell of Macrobrachium rosenbergii in different growth stages,Macrobrachium rosenbergii,Penaeus macronatum and Penaeus vannamericana collected from the market,and Macrobrachium rosenbergii and Penaeus nigra treated by different processing methods.The results showed that the SEM content of meat was always higher than 1.0 ?g/kg during the whole growth period under the drug-free feeding condition,and the SEM content in the shell of Macrobrachium rostenbergii increased rapidly from 20 days to 40 days,and the SEM content in the shell was 15.33-32.10 times higher than that in meat,which all exceeded the residual limit standard of SEM in China.Spot section prawns,South America white shrimp,roche spermatogenesis of SEM in the shrimp is not detected respectively0.76 ?g/kg,did not check out ? 0.43 ?g/kg,0.71 ? 2.72 ?g/kg,while the content of SEM of shrimp shell,were 3.04 ? 15.36 ?g/kg,2.42 ? 10.27 ?g/kg,26.38 ? 64.16 ?g/kg,three Zhong Yang Shi shrimp muscle and the SEM contents of shrimp shells are present a roche spermatogenesis section > spot distribution characteristics of shrimp > South America white shrimp;During heat treatment,with the increase of heating temperature and heating time,the mass loss and SEM content of shrimp meat samples will increase.When cooking and processing shrimp samples,the mass loss of muscle of macrobrachium rosenbergii and shrimps showed the characteristics of fried > boiled > steaming,while the changes of SEM content showed the characteristics of steamed > boiled > fried,and the three cooking methods all resulted in the increase of SEM content of shrimps.The results showed that endogenous SEM existed in all kinds of cultured shrimps,and it may come from shrimp shells.High temperature would lead to the increase of SEM content in shrimp meat,and temperature and moisture in the processing process would affect the SEM content in shrimp meat.(3)The different muscle and shell components of shrimp were used to explore the reasons for the different contents of semicarbazone,and the origin mechanism of endogenous SEM in cultured shrimp was preliminarily explored.In order to eliminate the false positive interference of furacillin,a specific marker other than SEM was used to detect the drug residues of furacillin in shrimp.Kjeldahl nitrogen determination method was used to determine the protein content,and automatic amino acid analyzer was used to determine the type and content of amino acids.Using 5-nitro2-furfural as a specific marker,a HPLC method for the determination of furacillin drug residues was established.The results showed that the protein contents in muscle were 19.83%,22.39%,21.32% and 24.65%, respectively,and the protein contents in shell were 10.63%,11.82%,10.02% and 13.22%,respectively.Roche spermatogenesis and spot section prawns,South America white shrimp shrimp amino acid concentration distribution,amino acid content in the muscle of the highest order is glutamic acid,aspartic acid,arginine,lysine,shrimp shell and amino acid content in the highest,in turn,is glutamic acid,aspartic acid,alanine,glycine,amino acid content in the shrimp cystine is the minimum order,tryptophan,histidine,methionine,amino acid content in the shrimp shell minimum of cystine,methionine,tryptophan,histidine;The linear range of 5-nitro2-furfural was 0.5?50 ?g/m L,and the correlation coefficient R2 was 0.9974.The limit of detection was 0.25 ?g/m L,the limit of quantitation was 0.5 ?g/m L,the spiked recovery of 5-NF in shrimp meat was 75.4%?83.7%,and the precision was 3.6%?5.4%.The results showed that the levels of protein or amino acid content alone could not reflect the levels of SEM content.Therefore,the interaction between amino acids and protein and other components should be linked to jointly study the generation and source mechanism of SEM in cultured shrimp.It is feasible to use5-nitro2-furfural(5-NF)as a drug-specific marker of furacillin to monitor the use of furacillin in aquaculture.