Department of Chemistry, Université de Montréal, Montréal, QC, Canada.
Department of Chemistry, Université de Montréal, Montréal, QC, Canada.
Anal Chim Acta. 2015 Jan 1;853:415-424. doi: 10.1016/j.aca.2014.10.037. Epub 2014 Oct 29.
The presence of antibiotics in the environment is of increased interest and, as modern mass spectrometers become more efficient, we are increasingly aware of traces of pharmaceuticals appearing in a wide range of environmental and biological matrices. The Q-Exactive mass spectrometer is part of these innovative hybrid high-resolution mass spectrometers (HRMS) which is often associated with peptide sequencing or metabolomics but with a limited number of studies focusing on its application to the quantification of small molecules in environmental and biological matrices. It combines the high resolving power (RP) performance of the Orbitrap with the high performance selectivity of the quadrupole. Tetracyclines (TCs) are a family comprising some of the most widely used antibiotics in veterinary medicine. This study presents the quantitative performances of the Q-Exactive by illustrating a new approach to quantify TCs using liquid chromatography coupled to a HRMS in a complex matrix, i.e., swine manure. The Q-Exactive was used at high-resolution in both full scan (FS) and targeted ion fragmentation (tMS(2)) modes. These two modes were optimized and compared to determine the most reliable and efficient approach to quantify TCs with good accuracy. The proposed method was optimized to obtain the best selectivity and sensitivity, thus eliminating false positive and allowing the detection of trace levels of analyte. The TCs were extracted from the matrix by sonication using McIlvaine buffer followed by an off-line solid phase extraction method to concentrate and clean the extracts. Both FS and tMS(2) modes presented good linearity (R(2)>0.991) and repeatability (RSD<15%). Mass accuracy was acceptable with values below 2 ppm. The method detection limits (MLD) calculated from the calibration curves ranged from 2.0 to 12 ng g(-1) for FS mode and from 1.5 to 3.6 ng g(-1) for tMS(2) mode. Accuracy and interday/intraday relative standard deviations were below 21% for both modes studied. TCs were quantified in real samples of swine manure with concentrations ranging from 29 to 75 ng g(-1). This study showed the possibility of using hybrid HRMS for trace detection and quantification of TCs in a complex matrix, thus avoiding false positive while achieving good selectivity and sensitivity.
环境中抗生素的存在引起了越来越多的关注，随着现代质谱仪变得更加高效，我们越来越意识到各种环境和生物基质中出现的痕量药物。Q-Exactive 质谱仪是这些创新型混合高分辨率质谱仪（HRMS）的一部分，它通常与肽测序或代谢组学相关联，但只有少数研究集中在其应用于环境和生物基质中小分子的定量分析上。它结合了 Orbitrap 的高分辨率性能和四极杆的高性能选择性。四环素（TCs）是一组在兽医学中广泛使用的抗生素。本研究通过展示一种新方法来定量分析复杂基质（即猪粪）中的 TCs，展示了 Q-Exactive 的定量性能。在高分辨率下，Q-Exactive 同时在全扫描（FS）和靶向离子碎片化（tMS(2)）模式下进行操作。优化了这两种模式并进行了比较，以确定最可靠和有效的方法来定量 TCs，同时保持良好的准确性。该方法经过优化，以获得最佳的选择性和灵敏度，从而消除假阳性并允许检测痕量的分析物。TCs 通过超声处理使用 McIlvaine 缓冲液从基质中提取，然后通过离线固相萃取方法浓缩和净化提取物。FS 和 tMS(2) 模式均表现出良好的线性（R(2)>0.991）和重复性（RSD<15%）。质量精度可接受，值低于 2 ppm。从校准曲线计算的方法检测限（MLD）范围为 FS 模式下 2.0 至 12 ng g(-1)，tMS(2) 模式下 1.5 至 3.6 ng g(-1)。两种模式下的准确度和日内/日间相对标准偏差均低于 21%。在猪粪的实际样本中定量检测到 TCs，浓度范围为 29 至 75 ng g(-1)。本研究表明，混合 HRMS 可用于痕量检测和定量分析复杂基质中的 TCs，从而避免假阳性，同时实现良好的选择性和灵敏度。
