Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
J Am Soc Mass Spectrom. 2022 Jul 6;33(7):1187-1193. doi: 10.1021/jasms.2c00040. Epub 2022 May 24.
Solid-phase microextraction (SPME)-direct mass spectrometry (MS) has proven to be an efficient tool for the rapid screening and quantitation of target compounds at trace levels. However, it is challenging to perform screening using both positive and negative modes in one analytical run without compromising scanning speed and detection sensitivity. To take advantage of the special geometry of a coated blade spray (CBS) blade, which consists of two flat sides coated with the same SPME coating, we developed a CBS-MS method that enables desorption and ionization to be performed in positive ionization mode on one side of a coated blade and negative ionization mode on the other side of the same blade. By simply flipping the blade 180°, MS analysis in both ionization modes on different sides can be completed in 40 s. Combining this approach with an automated Concept 96-blade-based SPME system allowed analysis for one sample in positive and negative modes to be completed in less than 1 min. The workflow was optimized by using a biocompatible polyacrylonitrile as an undercoating layer and a binder of polyacrylonitrile/hydrophilic-lipophilic balance (HLB) particles, which enabled the rapid analysis of 20 drugs of abuse in saliva samples in both positive and negative modes. The proposed method provided low limits of quantification (between 0.005 and 10 ng/mL), with calibration linear correlation coefficients ⩾ 0.9925, accuracy between 72% and 126%, and relative precision < 15% for three validation points.
固相微萃取（SPME）-直接质谱（MS）已被证明是一种快速筛选和定量痕量目标化合物的有效工具。然而，在不影响扫描速度和检测灵敏度的情况下，在一次分析运行中同时进行正离子模式和负离子模式的筛选具有挑战性。为了利用涂敷刀片喷雾（CBS）刀片的特殊几何形状，该刀片由两面涂有相同 SPME 涂层的两个平面组成，我们开发了一种 CBS-MS 方法，该方法能够在刀片的一侧进行正离子化模式下的解吸和离子化，而在刀片的另一侧进行负离子化模式下的解吸和离子化。只需将刀片翻转 180°，即可在 40 秒内完成不同侧的两种离子化模式的 MS 分析。将这种方法与基于自动概念 96 刀片的 SPME 系统相结合，允许在正离子化模式和负离子化模式下对一个样本进行分析，整个过程不到 1 分钟。通过使用生物相容性的聚丙烯腈作为底层涂层和聚丙烯腈/亲水-亲脂平衡（HLB）颗粒的粘合剂，优化了工作流程，从而能够在正离子化模式和负离子化模式下快速分析唾液样本中的 20 种滥用药物。该方法的检测限低（0.005 至 10 ng/mL 之间），校准线性相关系数 ⩾0.9925，准确度在 72%至 126%之间，三个验证点的相对精密度<15%。
