Study On The Growth Promotion Of Bean Sprouts By Chemical Synthetic Growth Regulators And Investigation On The Illegal Application Of Bean Sprouts On Market

Bean sprouts are a common vegetable in daily life.They are rich in nutrition,simple to produce,and regular consumption is of great benefit to people."Toxic bean sprouts" refer to bean sprouts made by illegally adding harmful chemical synthetic substances to bean sprouts in the production process.Because of illegal addition,the appearance of the finished product is improved,the production cycle is changed,and the output is increased.However,many of the residual substances are harmful to human body.At present,there are many bean sprouts similar to "toxic bean sprouts" in the market,which are thick,long,bright,white,and rootless.According to the insiders in the industry,in bean sprouts production,a new type of root-free production-increased bean sprout auxin has been used to replace the original AB powder,so as to escape food safety supervision and law enforcement.It may contain synthetic growth regulators such as naphthalic acid,2-methoxy-3,6-dichlorobenzoic acid,2,4-dichlorophenoxyacetic acid,2,4,5-trichlorophenoxyacetic acid,kinetin,isopentenyl adenine,zeatin,zeatin nucleoside,indole acetic acid,indole butyric acid,4-chlorophenoxyacetic acid,6-benzyladenine,etc,and the standard testing methods for these substances are imperfect.Therefore,it is of great practical significance to carry out the research for the detection methods of chemical synthesis of plant growth regulators residues in bean sprouts.In this paper,by optimizing the extraction solvent,extraction method,salt,dispersed solid phase extraction agent,constant volume solvent and chromatographic and mass spectrometric conditions in the pretreatment process,a new detection method for simultaneous determination of residues of 12 target compounds in bean sprouts was established,which uses 1%acetic acid-acetonitrile as extraction solvent,ultrasonic extraction method,sodium chloride to remove water and impurities,80 mg PSA+C18 as dispersed solid phase extraction agent,10%methanol-water as constant volume solvent and ultra high performance liquid chromatography-tandem triple quadruple bar mass spectrometry electrospray ion source switching mode under positive and negative ion monitoring mode.By investigating the matrix effect,detection limit,recovery and precision of this method,it was determined that 12 target compounds had good linear relationship in the concentration range of 1-50 ug/L(R2>0.997).Added 10 μg/kg、20 μg/kg、50 μg/kg these three additional standard levels to the blank matrix samples.The average recoveries were between 70.3%and 120.5%,the relative standard deviations(RSD)were between 1.8%and 13.9%(n=6),the detection limits(LOD)were between 3.2 and 16.5 μg/kg,and the quantitative limit(LOQ)were between 0.01 and 0.05 mg/kg,which met the requirements of 12 target compounds’ detection method.This method has simple sample pretreatment process,and it is sensitive and more accurate for qualitative and quantitative analysis,so it is suitable for rapid detection and analysis of 12 chemical synthetic plant growth regulators residues in bean sprouts.The risk of residues of chemical synthetic plant growth regulators in bean sprouts was investigated by self-developed detection method.Sampling test and data analysis were carried out to grasp the illegal addition situation of chemical synthetic plant growth regulators in bean sprouts on the market.After investigation,113 batches in 150 batches of bean sprouts were detected containing two prohibited substances,sodium 4-chlorophenoxyacetate and 6-benzyladenine,with a disqualification rate as high as 75.3%.This problem should be a nationwide problem.Experiments were carried out on the simulated growth of bean sprouts by using new bean sprout drugs.The appearance of the products was investigated.The common processing method of bean sprouts in our country:frying were also simulated in order to investigate the residues of additives before bean sprouts were grown up.The above-mentioned chemically synthesized plant growth regulators would not undergo obvious degradation and transformation after high temperature heat treatment,but would continue to be retained,was confirmed.