Food Safety Department, Teagasc, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland.
J Chromatogr A. 2010 Jul 2;1217(27):4612-22. doi: 10.1016/j.chroma.2010.05.007.
A new UHPLC-MS/MS (ultra high performance liquid chromatography coupled to tandem mass spectrometry) method was developed and validated to detect 38 anthelmintic drug residues, consisting of benzimidazoles, avermectins and flukicides. A modified QuEChERS-type extraction method was developed with an added concentration step to detect most of the analytes at <1 microg kg(-1) levels in milk. Anthelmintic residues were extracted into acetonitrile using magnesium sulphate and sodium chloride to induce liquid-liquid partitioning followed by dispersive solid phase extraction for cleanup. The extract was concentrated into dimethyl sulphoxide, which was used as a keeper to ensure analytes remain in solution. Using rapid polarity switching in electrospray ionisation, a single injection was capable of detecting both positively and negatively charged ions in a 13 min run time. The method was validated at two levels: the unapproved use level and at the maximum residue level (MRL) according to Commission Decision (CD) 2002/657/EC criteria. The decision limit (CCalpha) of the method was in the range of 0.14-1.9 and 11-123 microg kg(-1) for drugs validated at unapproved and MRL levels, respectively. The performance of the method was successfully verified for benzimidazoles and levamisole by participating in a proficiency study.
建立并验证了一种新的 UHPLC-MS/MS（超高效液相色谱-串联质谱）方法，用于检测 38 种驱虫药残留，包括苯并咪唑类、阿维菌素类和杀螺剂。开发了一种改良的 QuEChERS 型提取方法，并增加了浓缩步骤，以便在牛奶中检测到大多数分析物的浓度<1μg/kg。驱虫药残留用硫酸镁和氯化钠提取到乙腈中，以诱导液-液分配，然后用分散固相萃取进行净化。提取物浓缩到二甲基亚砜中，用作保持剂，以确保分析物保持在溶液中。采用电喷雾离子化快速极性切换，单次注射即可在 13 分钟的运行时间内同时检测到正离子和负离子。该方法按照欧盟委员会决定（CD）2002/657/EC 标准，在未批准用途水平和最大残留限量（MRL）水平进行了验证。未批准用途水平和 MRL 水平验证的药物的方法检测限（CCα）分别为 0.14-1.9 和 11-123μg/kg。该方法的性能通过参加能力验证研究，成功验证了苯并咪唑类和左旋咪唑的有效性。
