Grujić Svetlana, Vasiljević Tatjana, Lausević Mila
Department of Analytical Chemistry, Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
J Chromatogr A. 2009 Jun 19;1216(25):4989-5000. doi: 10.1016/j.chroma.2009.04.059. Epub 2009 Apr 24.
This paper describes development, optimization and application of analytical method for determination and reliable confirmation of nineteen pharmaceuticals from different therapeutic classes (antibiotics--beta-lactams, cephalosporines, sulfonamides, macrolides and tetracyclines; benzodiazepines; antiepileptics and analgoantipyretics) in surface and ground waters at ng l(-1) levels. Water samples were prepared using solid-phase extraction and extracts were analyzed by liquid chromatography-ion trap-tandem mass spectrometry with electrospray ionization in both positive and negative ionization mode. The efficiency of ten different SPE cartridges to extract diverse compounds from water was tested. The pH-value of the water sample, the volume of elution solvent and the sample volume were optimized. Matrix effect, especially pronounced for cephalexin and metamizole, was eliminated using matrix-matched standards. It was determined that extraction should be performed at pH approximately 7.5, i.e. without pH adjustment, and at pH 3, depending on the analyte. Azithromycin, doxycycline and acetylsalicylic acid must be extracted in acidic environment, whereas extraction of paracetamol, ampicillin, erythromycin and metamizole should be performed without pH adjustment. Repeatability of the method was generally lower than 20%. The estimated limits of detection were in the range from 0.15 to 12.46 ng l(-1). The method was applied to 26 water samples for monitoring of selected drug residues. Results revealed the presence of carbamazepine (80% of water samples), azithromycin (23%), as well as trimethoprim and paracetamol (both 15%). The most striking was the false positive signal of diclofenac in every analyzed water sample. Confirmation of the positive results was performed by repeated injection of the positive sample extracts using confirmatory method with additional transitions.
本文描述了一种分析方法的开发、优化及应用，该方法用于测定和可靠确证地表水体和地下水体中19种不同治疗类别（抗生素——β-内酰胺类、头孢菌素类、磺胺类、大环内酯类和四环素类；苯二氮䓬类；抗癫痫药和止痛退烧药）的药物，检测限为纳克/升水平。水样采用固相萃取法制备，萃取物通过液相色谱-离子阱-串联质谱联用仪进行分析，采用电喷雾电离，同时使用正离子和负离子电离模式。测试了10种不同的固相萃取柱从水中萃取多种化合物的效率。对水样的pH值、洗脱溶剂体积和样品体积进行了优化。使用基质匹配标准消除了基质效应，尤其是对头孢氨苄和安乃近的基质效应。确定萃取应在pH约为7.5（即不进行pH调节）以及pH为3时进行，具体取决于分析物。阿奇霉素、强力霉素和乙酰水杨酸必须在酸性环境中萃取，而对乙酰氨基酚、氨苄青霉素、红霉素和安乃近的萃取应在不调节pH的情况下进行。该方法的重复性一般低于20%。估计检测限在0.15至12.46纳克/升范围内。该方法应用于26个水样，以监测选定的药物残留。结果显示，水样中存在卡马西平（80%的水样）、阿奇霉素（23%）以及甲氧苄啶和对乙酰氨基酚（均为15%）。最引人注目的是，在每个分析的水样中都出现了双氯芬酸的假阳性信号。通过使用具有额外跃迁的确证方法对阳性样品萃取物进行重复进样，对阳性结果进行确证。
