Study On Determination Methods Of Chloramphenicol And Quinolone Antibiotics In Environment

Chloramphenicol antibiotics and quinolone antibiotics are two kinds of antibiotics commonly used in human and animals,which will increase the risk of environmental pollution in the process of production and use.This will not only damage the microbial community structure and inhibit plant growth,but also may enter the human body through the food chain,increasing the risk of bacterial resistance in the human body and having adverse effects on the hematopoietic system,cardiovascular system and gastrointestinal system.Combining the characteristics of the water and soil matrixes with the different properties of the analytes,the instrument test conditions and the pretreatment methods were optimized.The results are as follows:（1）The determination methods of three chloramphenicol antibiotics and their metabolite in water and soil were studied by ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）.Water samples were vortically extracted for 3min under basic condition（p H=10）by a mixture of acetonitrile and ethyl acetate（7:3,V/V）,and the supernatant was purified by anhydrous Mg SO₄after centrifugation.The soil samples were vortically extracted for 2 min by acetonitrile containing 3%ammonia（V/V）,and the supernatant was purified with PSA（N-propyl ethylenediamine）and anhydrous Mg SO₄after centrifugation.The analytes were separated on a ZORBAX SB-Aq column（2.1 mm×150 mm,3.5μm）by isocratic elution using methanol-water（1:1,V/V）as mobile phase,then determined with electrospray ion source in positive and negative ion switching mode（ESI⁺/ESI^-）scanning under multiple reaction monitoring（MRM）mode,quantified by the matrix matching external standard method.The results showed that in surface water,wastewater and soil,the linear relationships of the four analytes were good in their respective concentration ranges,and the correlation coefficients（R²）were all greater than0.999.The limits of detection（LODs）were 0.002～0.032μg/L,0.001～0.036μg/L and0.01～0.06μg/kg,respectively.The limits of quantitation（LOQs）were 0.007～0.106μg/L,0.003～0.118μg/L and 0.05～0.19μg/kg,respectively.The average recoveries were73.56%～118.41%,72.64%～116.30%and 87.23%～108.57%at low,medium and high spiked concentrations,respectively.The relative standard deviations（RSD_S）were1.21%～8.36%,2.93%～9.00%and 0.36%～6.55%,respectively.The methods were quick,sensitive,accurate and reproducible,which were suitable for the determination of three chloramphenicol antibiotics and their metabolite in water and soil.（2）The high throughout determination methods of 27 quinolone antibiotic residues in water and soil were studied by UPLC-MS/MS.Water samples were ultrasonically extracted for 5 min under acidic conditions（p H=3）by acetonitrile.Soil samples were vortically extracted for 10 min by acetonitrile containing 7%formic acid（V/V）,and the supernatant was purified with anhydrous Na₂SO₄after centrifugation.The analytes were separated on a BEH C₁₈column（2.1 mm×100 mm,1.7μm）by gradient elution using acetonitrile-0.1%formic acid aqueous solution as mobile phase,then detected with electrospray ion source in positive ion mode（ESI⁺）scanning under MRM mode,quantified by the matrix matching external standard method.The results showed that in surface water,wastewater and soil,the linear relationships of 27 analytes were good in their respective concentration ranges,and R²were all greater than 0.999.The LODs were0.002～0.181μg/L,0.01～0.50μg/L and 0.008～0.319μg/kg,respectively.The LOQs were0.007～0.604μg/L,0.03～1.68μg/L and 0.027～1.063μg/kg,respectively.The average recoveries were 64.60%～118.55%,65.13%～119.40%and 63.27%～112.04%at three different spiked concentrations,respectively.The RSD_Swere 1.20%～9.92%,2.16%～9.88%and 1.33%～9.86%,respectively.The methods showed the advantages of accurate quantitation and good sensitivity,which could meet the requirements for simultaneous determination of 27 quinolone antibiotics in water and soil.