Liquid Phase Microextraction-high Performance Liquid Chromatography For The Determination Of Chloramphenicol Residues In Honey

In order to effectively prevent and treat bee larvae rot,chloramphenicol drugs were smeared on the beehives by beekeepers.However,the unreasonable use of these drugs may result in the residues of chloramphenicol in the honey,which will have a directly effect on the consumer's health and even cause some irreparable damage.Therefore,it is necessary to establish an efficient and accurate analytical method for the detection of chloramphenicol residues in the honey.Based on High performance of liquid chromatography?HPLC?,three liquid phase microextraction pretreatment techniques were developed to detect chloramphenicol residues in honey samples.1.Ionic liquids-dispersed liquid-liquid Microextraction-High Performance Liquid Chromatography?IL-DMLLE-HPLC?was adopted to detect chloramphenicol residues in the honey.The optimum extraction conditions for the experiment are as follows:the extractant was[OMIM][BF₄]and its volume was 90?L;the dispersant was methanol and its dosage was 800?L;the pH value of solution was 3;the salt concentration was 1.5%;and the extraction time was 5 min.Under the optimum extraction conditions,the linear regression equation of concentration in the range of 0.05¹.00 ug/mL was y=159.38x+5.4371,R² was 0.9977,LOD was 5.4 ng/mL,RSDs were 4.3⁵.1%,and enrichment multiples were 26.2²8.7 times.The recoveries of real samples were 89.4⁹2.6%.The method has the advantages of low detection limitation,short extraction time,green and environmental protection of the selected extractant?ionic liquids?and low dosage.2.In the method of IL-DMLLE,the traditional dispersant is used in a large amount,which has the disadvantages of environmental pollution,enrichment ratio and low recovery rate.In this paper,we achieved some improvements of IL-DMLLE by using surfactantasdispersantandultrasonic-assistedextraction.And?IL-SA-UA-DLLME-HPLC?had been developed and employed to detectdetection of chloramphenicol residues in the honey.The optimum extraction conditions are as follows:the extractant was[OMIM][BF₄],the volume of extractant was 120?L;the surfactant was Tween80,the concentration of surfactant was 0.06 mmol/L;solution's pH value was5;The time of ultrasonic extraction was 6 min.Under the optimal extraction conditions,the linear regression equation with concentration in the range of 0.05¹.00?g/mL was y=485.69x+3.0174,R² was 0.9988,LOD was 3.4 ng/mL,RSDs were 4.0⁴.2%,enrichment multiples were 58.9⁶1.8 times,the recovery rate of the actual sample detections were 92.6⁹5.7%.The results are satisfactory,and the method had the advantages of rapidity,high enrichment ratio and environmental friendliness.3.Two-phase hollow fiber liquid-liquid Microextraction-High Performance Liquid Chromatography?2P-HF-LPME-HPLC?was used in detection of chloramphenicol residues in the honey.The optimum extraction conditions are as follows:the extractant was TBP;the volume of extractant was 10 uL;stirring speed was 800 r/min;extraction time was 40 min;the concentration of sodium chloride was 30%;temperature was 30°C;pH value was 4.Under the optimal extraction conditions,the linear regression equation of chloramphenicol concentration in the range of 0.05⁰.50?g/mL was y=1614.4x+2.8709,R² was 0.9998,LOD was 1.1 ng/mL,RSDs were 2.4⁴.4%,and the enrichment multiples of chloramphenicol were 199.4²10.2 Times.Applied to actual sample testing,the recovery rates were 90.1⁹7.0%.The method has the advantages of less organic solvent consumption,high enrichment ratio and good reproducibility.