Determination Of Fluoroquinolones Multiresidue In Chicken Muscle By MSPD-HPCE

Fluoroquinolones is a group of synthetic antimicrobialagents that are widely used in veterinary medicine.The use of the drugs in veterinary applications can leave residues in edible animal tissues,which may be directly toxic or cause resistant human pathogens and possible allergic hypersensistivity reaction in human.So,it is very important to establish an adequate analytic method for fluoroquinolones multiresidue determinationin animal in order to ensure health and safety of consumer.High performance capillary eleetrophoresis(HPCE) and liquid chromatography-mass spectrometry(LC-MS) method for multiresidue determining lomefloxacin,ofloxacin, enrofloxacin and Pefloxacin in chicken tissues were ensured.The different pretrentment such as matrix solid-phase dispersion,liquid-liquid extraction and solid-phase extraction were established.The results as follow:1 Establishment of HPCE method for determining four fluoroquinolonesBy introduced of orthogonal design,different paramenters were optimized such as the pH and concentration of running buffer,the separation voltage and the runnion tamperation, A high performance capillary eleetrophoresis method has been developed for the simultaneous separation and determination of four FQs.Under optimum condition,the running buffer consisted of 35 mmol·L^-1 sodium borate(pH 8.8),separation voltage at 28kV,running temperation at 25℃,the four analytes can be well separated within 7.0min. The calibration curves for the peak area is good linear relation in the range of 0.5-20μg/g, and the Correlation coefficient are between 0.9990 to 0.9996.2 Establishment of sample pretrentment technique in chicken muscleTheer method MSPD,LLE and SPE had compared,MSPD was the optimal method.LLE:This experiment were compared,such as phosphate buffer,sodium hydroxide/ acetonitfile,acetonitrile,acetic acid/acetonitrile.The recovery of acetonitrile was between 79.2 to 107.1%.SPE:This experiment compared the different eluate,such as methanol,acetonitrile, n-hexane,4%ammonia water- methanol and dichloromethane.The result was 4%ammonia water-methanol's returnas-ratio was between 77.66 to 90.59%.MSPD:Different parameters were optimized,such as component of washing eluate, eluate and volume of eluent,evaluating the recoveries of tissues.A multriresidue extraction method based on matrix solid-phase dispersion was developed for the extraction of fluoroquinolones from chicken tissues.The mean recoveries of fluoroquinolones in chicken muscle was between 81.46%to 93.39%.These method caused returns-ratios of more than 70%,The LLE processing was disturbanced many material,that coulde impacted the quantitative of goal;SPE method operation was more complexed than MSPD technique,but the recovery less than MSPD technique;MSPD technique deale with samples pure relatively and waste less time and elution.Whether in comperation or recovery,MSPD technique was the Optimttm sample pretreatment method,and the recoveries at spiked was between 79.5 to 91.6%.3 MSPD-HPCE for the simultaneous determination of residues of four fluoroquinolones in chicken muscle was determined.The optimal method was used to determine the residues of four fluoroquinolones in chicken tissues,the residues of four fluoroquinolones were 1.219μg/g(LUO),1.045μg/g(OFL),0.961μg/g(ENR),3.401μg/g(PEF),The limit of determined(LOD)of LUO,OFL,ENR and PEF are between 51 to 100μg/kg4 MSPD-HPCE was authenticated by liquid chromatography/mass spectrometry method for determining four fluoroquinolonesChromatographic condition:C18 column(2.1 mmI.D×150mm length ) with acetonitrile- 0.1%formic acid as the mobile phase.The optimized stepwise linear gradient elution used is following:from 0 to 7 min,the initial mobile phase contains of acetonitrile from 20%to 70%,and this acetonitrile percentage is maintained to 10 min,the percentage of acetonitrile decreases to 20%,and then remains constant to 10min.Flow rate was 0.2mL/min with an injection volume of 2μL.MS system:positive ionization mode with the drying nitrogen gas flow of 0.75 L/min,and with the nebulizing nitrogen gas was flowed of 0.15 L/min;the ample cone voltage was 4.SkV;capillary temperature was 180℃and capillary voltage was 13kV;air collision with helium;full scan mode in the range of m/z 100 to 400.In positive ionization mode,the FQs loss of CO₂,H₂O,These features will help to analysis the structure of fluoroquinolones.The matrix solid phase dispersion-high performance capillary electrophoresis was simple and rapid simultaneous determination of fluoroquinolones residues in chicken tissues,which according with the requirement of residual analysis.So,it is important theory and practice significance to monitor four fluoroquinolones in animal food.