Study On Determination Of Veterinary Antibiotics In Soil

Veterinary antibiotics are widely used in the prevention and treatment of animal diseases,as well as in animal husbandry to promote the production and growth of animal.Veterinary antibiotics in animals are not metabolized completely,and also can be excreted by animals as parent compounds entering the soils by the application of organic fertilizer.In recent years,the increasing use of these drugs has caused substantial environmental problems,which proved to be a matter of great concern.Therefore,in order to assess the environmental impact of antibiotics in soil,a reliable,accurate method for the determination of veterinary antibiotics excreted in soil environmental is necessary.This paper selected 38 common veterinary antibiotics containing sulfonamides,quinolones,tetracyclines,macrolides,beta-lactam as targets,and developed the determination of antibiotics in soils by the optimization of chromatographic condition,extraction and clean-up procedure,ultimately.ObjectThe aim of the study was to develop a simple,effective,and reliable multi-residue method based on SPE-LC-MS/MS and QuEChERS-LC-MS/MS procedure for the determination of selected antibiotics in soil.MethodSPE:The developed method was based on extraction with ACN:EDTA:McIlvaine buffer,followed the purification by HLB column.After eluted with 6ml methanol,the elutriant was evaporated to approximately dryness under nitrogen.Then redissolve the residue in 1 ml of MEOH:H2O?1:1,v/v?for LC–MS/MS analysis.QuEChERS:The developed method was based on extraction with ACN:EDTA:McIlvaine buffer,clean-up with dispersive solid phase extraction?d-SPE?adsorbent using primary secondary amine?PSA?,octadecylsilane?C18?,transfer 1ml of the supernatant into a tube,and evaporated the supernatant under nitrogen to approximately dryness.Then redissolve the residue in 1 ml of MEOH:H2O?1:1,v/v?for LC–MS/MS analysis.ResultsSPE:The results performed good recoveries at seven spiking levels(2.0,5.0,10.0,20.0,50.0,100.0,200.0?g·kg^-1)ranged from 50.0%to 110.0%with RSD below 20%?n=5?.The method limit of quantification?LOQ?was in the range of 2⁵?g·kg^-1 for most analytes.Good linear regression coefficients greater than 0.990 was obtained.QuEChERS:The results performed good recoveries at seven spiking levels(2.0,5.0,10.0,20.0,50.0,100.0,200.0?g·kg^-1)ranged from 61.4%to 118.9%with RSD%below 20%?n=5?.The method limit of quantification?LOQ?was in the range of 2–5?g·kg^-1 for most analytes.Good linear regression coefficients greater than 0.990 was obtained.ConclusionThe study developed SPE-based and QuEChERS-based methods for the determination of veterinary antibiotics residues in soil,which performed Advantages and disadvantages.The SPE method was applied to the simultaneous determination of 37 antibiotics in the soil,obtained satisfactory recoveries and relative standard deviation.However,the steps are tedious,time-consuming,expensive.It is a certain degree of difficulty for a large number of samples.Compared with the SPE method,the QuEChERS method has less application of antibiotics.However,the QuEChERS method is simple,time-saving,cheap,which also obtained satisfactory recoveries and relative standard deviations.