自动上样固相萃取-超高效液相色谱-串联质谱法同时测定水中9类43种抗菌药物残留

Simultaneous determination of 43 antibacterials from nine categories in water using automatic sample loading-solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

为了实现水中抗菌药物快速、准确、高通量的分析,采用自动上样固相萃取-超高效液相色谱-串联质谱技术,建立了一种能够快速、稳定地分析水中9类(磺胺类、喹诺酮类、氟喹诺酮类、四环素类、林可酰胺类、大环内酯类、硝基咪唑类、双萜烯类、二氢叶酸还原酶抑制剂类)43种抗菌药物多残留同步分析方法。水样经0.45μm水相滤膜过滤,加入一定量的磷酸二氢钠及乙二胺四乙酸二钠,并用磷酸调节pH至2.34,加入内标混匀,使用自制的自动上样装置进行上样,Oasis HLB固相萃取柱富集净化。利用Waters Acquity UPLC BEH C_(18)柱(50 mm×2.1 mm,1.7μm)进行分离,以含0.1%甲酸的甲醇-乙腈(2∶8,v/v)混合溶液-0.1%甲酸水溶液为流动相进行梯度洗脱,采用电喷雾正离子多反应监测模式进行分段扫描,内、外标法相结合的方式分析目标物。结果显示,43种抗菌药物在各自的线性范围内线性关系良好,方法的检出限为0.004~1.000 ng/L,定量限为0.012~3.000 ng/L,加标回收率为53.7%~130.4%,相对标准偏差为0.9%~13.2%。采用该方法对取自长江江阴段、锡澄运河江阴段各3份水样以及6份自来水样进行检测。6份自来水中均未检测到抗菌药物,6份取自长江江阴段、锡澄运河江阴段的水样中共检出20种抗菌药物,除四环素类外,其余类别均有检出,其中,以磺胺甲恶唑含量最高(8.92~11.03 ng/L),泰妙菌素和沃尼妙林两种双萜烯类抗菌药物在自然水体中普遍有检出。该法准确、灵敏、快速,适用于水中43种抗菌药物的检测。

Antibacterials represent a pharmaceutical class that is extensively used and consumed worldwide.The presence of a large number of antibacterial agents in water could result in antibiotic resistance.Thus,the development of a fast,accurate,and high-throughput method to analyze these emerging contaminants in water is necessary.Herein,a method was developed to achieve the simultaneous determination of 43 antibacterials from nine pharmaceutical categories(i.e.,sulfonamides,quinolones,fluoroquinolones,tetracyclines,lincosamides,macrolides,nitroimidazoles,diterpenes,and dihydrofolate reductase inhibitors)in water using automatic sample loading-solid phase extraction(SPE)-ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Because the properties of these 43 antibacterials are quite different,the main objective of this work is to develop an extraction procedure that would enable the simultaneous analysis of a wide range of multiclass antibacterials.Given this context,the work presented in this paper optimized the SPE cartridge type,pH,and sample loading amount.Multiresidue extraction was performed as follows.The water samples were filtered through 0.45μm filter membranes,added with Na_(2)EDTA and NaH_(2)PO_(4),and pH-adjusted to 2.34 using H_(3)PO_(4).The solutions were then mixed with the internal standards.An automatic sample loading device fabricated by the authors was used for sample loading,and Oasis HLB cartridges were used for enrichment and purification.The optimized UPLC conditions were as follows:chromatographic column,Waters Acquity UPLC BEH C_(18) column(50 mm×2.1 mm,1.7μm);mobile phases,methanol-acetonitrile(2∶8,v/v)solution containing 0.1% formic acid and 0.1% formic acid aqueous solution;flow rate,0.3 mL/min;injection volume,10μL.The compounds were step scanned using an electrospray ionization source in the positive and multiple-reaction monitoring(MRM)modes,and analyzed by internal and external standard methods.The results showed that the 43 compounds achieved high linearity in their respective linear ranges,with correlation coefficients(r^(2))greater than 0.996.The limits of detection(LODs)of the 43 antibacterial agents ranged from 0.004 ng/L to 1.000 ng/L,and their limits of quantification(LOQs)ranged from 0.012 ng/L to 3.000 ng/L.The average recoveries ranged from 53.7% to 130.4%,and the relative standard deviations(RSDs)were between 0.9% and 13.2%.The method was successfully applied to the determination of six tap water samples from different districts and six water samples obtained from the Jiangyin section of the Yangtze River and Xicheng Canal.No antibacterial compound was detected in any of the tap water samples,but a total of 20 antibacterial compounds were detected in the river and canal water samples.Among these compounds,sulfamethoxazole showed the highest mass concentrations,ranging from 8.92 to 11.03 ng/L.The types and contents of antibacterials detected in the Xicheng Canal were greater than those found in the Yangtze River,and two kinds of diterpenes,namely tiamulin and valnemulin,were found easily and commonly in water sample.The findings indicate that antibacterial agents are widespread in environmental waters.The developed method is accurate,sensitive,rapid,and suitable for the detection of the 43 antibacterial compounds in water samples.