Simultaneous and rapid detection of 55 antibacterial drugs in organic fertilizer using UPLC-MS/MS
An ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method was established for the simultaneous detection of 55 types of antibacterial drugs,including sulfonamides,macrolides,and quinolones,in organic fertiliz-er.After grinding and sieving the organic fertilizer into experimental samples,they were purified using HLB solid-phase extraction col-umn.After loading,the samples were sequentially washed with deionized water and 5%acetonitrile aqueous solution,eluted with methanol/ethyl acetate solution(volume ratio 7∶3,containing 5%ammonia),blown dry with nitrogen,and re-dissolved in 0.1%for-mic acid water/acetonitrile(volume ratio 9∶1);measurement was carried out in a multi reaction detection mode,with the external stan-dard method for quantification.The results showed that among the four batches of organic fertilizers,55 drugs had a good linear rela-tionship(R2>0.990)within the range of 1.0~100 μg/kg,the detection limit of this method was 2.0~7.5 μg/kg,the quantitative limit was 5.0~25.0 μg/kg,the recovery rates of various drugs were 60.2%~118.7%,the relative standard deviation within the batch(n=5)was 0.5%~15.0%,and the relative standard deviation between batches(n=20)was 4.3%~24.1%.This method was simple and reliable,with a good purification effect,and was suitable for the simultaneous detection of sulfonamide,quinolone,and macrocyclic lipid drugs in organic fertilizer.