Study On A New Method For Detecting Phthalate Esters In Pepper And Its Planting Environment

Plasticizer Phthalate esters(PAEs)are typical environmental hormones,increases the risk of obesity,type 2 diabetes,cardiovascular disease,and so on.Plastic mulching film and plastic greenhouses are widely used in modern agriculture.PAES is the raw material and main additive of plastic mulching film and plastic greenhouses.PAES is easy to seep out from plastics,pollute the air,soil and water,and migrate and enrich into plant foods,which poses a certain food safety risk.The detection of PAES in soil and vegetables has the difficulty of many interfering substances,and the detection of PAES in water has the difficulty of very low concentration.In this paper aiming at these difficulties,pepper and its planting soil,and water as the main research object,establish determination of capsaicin and its planting of 7 kinds of PAEs in soil,water source method:adopt high purity specificity adsorption single-walled carbon nanotubes PAEs in soil,chili,avoid the matrix interference,using magnetic carbon nanotubes PAEs in farmland irrigation water adsorption and enrichment.Main research contents and results:A new rapid and accurate method for the determination of seven kinds of PAEs in soil was established by using the high purity single-walled carbon nanotubes with strong adsorption properties for target compounds as the pretreatment adsorption material and the self-made glass solid phase extraction(SPE)column combined with GC-MS.The adsorbent dosage was 0.2 g,and n-hexane was the best eluent.The correlation coefficients of 7 PAEs were greater than 0.9992 in the concentration range of 0.05-1.00?g/mL.The limits of quantification(LOQ)were 0.01-0.03mg/kg.The spiked recoveries were 90.4%-111.7%with RSDs of 4.5%-11.2%.The prepared high-purity single-walled carbon nano tube glass SPE column can be reused many times after being washed by 3mL toluene,which greatly reduces the analysis cost.Magnetic multi-walled carbon nanotubes(MNP-MWCNTs)were synthesized by co-precipitation method to enrich PAEs in irrigation water.Combined with GC-MS,seven PAEs analysis methods in irrigation water were established.The results show that MNP-MWCNTs can speed up the extraction and phase separation of samples,save the operation steps of sample purification through the column,and save the sample treatment time and experimental cost.The dosage of MNP-MWCNTs was 20mg,the eluent was 1mL toluene-acetone solution(1+3,v/v),and the oscillation desorption time was 4 min.The limits of quantification of DMP,DEP,DIBP,DBP and BBP were 0.01mg/L,and DEHP and DNOP were 0.10mg/L.The recoveries were 81.6%-102.7% with RSDs of 2.5%-8.2%.Using high-purity single-walled carbon nanotubes as dispersion solid phase extraction material,combined with GC-MS,a new rapid and accurate analytical method for the determination of seven PAEs in pepper was established.The optimal dosage of pure single-walled carbon nanotubes was 80mg,and the optimal adsorption purification time was 6min.The correlation coefficients of all the seven PAEs were higher than 0.9992 in the linear concentration range of 0.1-5.0?g/mL.The limits of quantification of DMP,DEP,DIBP,DBP and DEHP were 0.015mg/kg,and that of BBP and DNOP was 0.250mg/kg.The recoveries were 82.0%-104.5%with RSDs of 4.2%-10.4%.Three plasticizers,including BBP,DNOP and DEHP,were detected in soil,water and pepper samples from the two bases.The method of this paper is accurate?fast?satisfy the soil,water for irrigation in farmland?the detection of 7 PAEs in pepper is required.