| Pesticide is chemical synthesis or natural preparations used for preventing and controlling pests and rodents,and regulating the growth of insects and plants.Not only in the fields of agriculture and conservation forestry,it also plays an important role in regulating water quality and promoting high-yield of aquaculture.However,due to the wide use of pesticides,the problem of pesticide residue is becoming serious.Pesticides remaining in the environment are accumulated into crops and aquatic organisms and enter the human body through the food chain,which posing a great threat to human health.Expect enrichment from the environment(water and sediment),pesticide residues in aquatic products are mainly derived from the use of pesticides or fishery drugs in the breeding process.At present,the pesticides commonly used in planting and aquaculture include organophosphorus pesticides,organochlorine pesticides,carbamate pesticides,imidazole pesticides and triazine pesticides,etc.When the aquatic products with high pesticide residue was consumed or people was explosed in the environment of high concentrations of pesticides,the the risk of some cancer,chronic diseases,and nervous system diseases will be increased.Therefore,it is of great significance for supervising the pesticides in the breeding environment and aquatic products to ensure human health and aquatic product quality and safety.At present,there are few studies on pesticide residues in the aquaculture environment and aquatic products,especially the study on the simultaneous determination of different types of pesticides.The existing detection technologies have some deficiencies,such as single detection target,and no corresponding detection methods for some pesticides.In addition,the existing monitoring methods mainly concerned the residues of known drugs,and it is impossible to know whether the measurement object contains other drugs.Due to the limitation of detection technology,it is impossible to know the pesticide pollution status of aquaculture environment and aquatic product timely and accurately.So,it is difficult to find hidden hazards for related aquatic products,and hard to judge and deal with related safety accidents timely.Therefore,it is urgent to established a simultaneous and high efficiency screening methods for multi-residue of pesticide in aquaculture environment and aquatic products.It is a reliable technical support for supervision and risk assessment of pesticide residues in aquaculture environments and aquatic products.This reaserch aimed at the pesticide pollution characteristics of aquatic product in the breeding process,and the regulatory hotspots of pesticide at domestic and foreign.A pesticide screening database for screening different pesticides was builded by ultra-high performance liquid chromatography-Q/Orbitrap quadrupole mass spectrometer(UHPLC-Q/Orbitrap MS).A high-throughput instrumental analysis method for the simultaneous determination of 87 pesticides was established.According to the different characteristics of matrix,the pre-treatment methods were developed and researched,and a high-throughput rapid screening technology for pesticide residues in aquacluture environment and aquatic products was established.Finally,the established screening technology was applied to the preliminary investigation of pesticide pollution status for the aquaculture environment and aquatic product in Chongming,and the pollution characteristic and potential hazard was analyzed.Results are as followed:1.A qualitative database for the screening of 87 pesticides was builded by UHPLC-Q/Orbitrap MS.The database contains basic chemical information of compounds,chromatographic retention time,precursor ion,the adduct and fragment ion.The database can be used for non-target screening,and accurate qualitation of the targets can be achieved with the chromatographic and MS fingerprint information of compound.2.A high-throughput instrumental analysis method for the simultaneous analysis of 87 pesticides was developed through the study of mass spectrometry and chromatographic conditions.The optimal chromatography conditions are: Accucore a Q-MS column(100 mm × 2.1 mm,2.6 ?m),flow rate: 0.3 m L/min;mobile phase is 0.1% formic acid aqueous solution(containing 5 mmol/L ammonium formate)and 0.1% formic acid in methanol(containing 5 mmol/L ammonium formate).Mass spectrometry paramaters: H-ESI source;spray voltage: 3200 V(+),2800 V(-);auxiliary gas heating temperature: 350 ?;ion transfer tube temperature: 325 ?.scanning mode: Full Scan / dd-MS2(Top N)mode;scan range: 100 ? 1000 m / z;resolution: 70,000(Full MS);17500(MS/MS);trigger threshold: 5 × 10~5(Full MS);1 × 10~5(MS/MS).Under the best instrumental analysis conditions,4 isomers are effectively separated.It is more conducive to accurate qulification of 87 compounds.3.A screening method was established for the simultaneous determination of 87 pesticides in aquaculture waters.The method screening limits(MDL)for 71 pesticides are between 0.002 and 0.04 ?g/L,the MDL for 11 pesticides are between 0.04 and 1 ?g/L.The MDL for five pesticides were greater than 1 ?g/L.The method has good reproducibility,accurate qualitative and simple operation,and can be used for rapid screening and qualitative and semi-quantitative analysis of unknown pesticides in aquaculture waters.4.A screening technology for the simultaneous analysis of 87 pesticides in the sediment was established.The MDL of 75 pesticides are between 1 ?g/kg and 25 ?g/kg,MDL of 8 pesticides are between 25 ?g/kg and 200 ?g/kg,the method screening limit of the four pesticides is greater than 200 ?g/kg.The method is easy to operate,with high accuracy and good reproducibility,and it can be used for rapid screening and qualitative and quantitative analysis of unknown pesticides in sediment.5.A rapid simultaneous screening method for 87 pesticide residues in aquatic products was established.In this method,the method screening limits at the range of 1 ?g/kg-25 ?g/kg of are 71 pesticides in carp and crayfish,the MDL of 9 pesticdes are between 25 ?g/kg and 100 ?g/kg,the MDL of 7 pesticdes greater than 100 ?g/kg.In the carb,the MDL of 61 pesticides are between 1 ?g/kg and 25 ?g/kg,the MDL of 6 pesticdes are between 25 ?g/kg and 100 ?g/kg,the MDL of 20 pesticdes greater than 100 ?g/kg.The pretreatment method is simple and high applicability,which can meet the needs for simultaneous screening of multiple pesticide residues in aquatic products.6.The pesticide pollution in aquaculture environment and aquatic products in Chongming was investigated and analyzed.The survey results:(1)The main pesticide pollution in aquaculture inlet water comes from pesticide in agriculture and other fields.The content of avermectin and ethoxyquinoline in two pond waters exceeds 400 ng/L,which increases the risk of enrichment in aquatic products.Pentachlorophenol sodium,a banned fishery drug,was detected in the pond,but the content did not exceed the standard limit of 10 ?g/L in GB11607-89 water quality standard for fishery.(2)Phiophos and Thiofanox were detected in two the bottom sediment of pond inlets,and the content was greater than 20 ?g/kg,the risks for the quality of aquatic products should be paid attention.(3)In addition,compounds with high frequent detcetion in aquatic products include ethoxyquin,prometryn,and phoxim;the amount of most confirmed compounds did not exceed 2.00 ?g/kg;and the content of ethoxyquin in two samples is exceed 200 ?g/kg,which exceeding the limit of European Union standards limit 0.05 mg/kg for ethoxyquin. |
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