Analysis of new psychoactive substances (NPSs) still poses a challenge for many institutions due to the number of available substances and the constantly changing drug market. Both new and well-known substances keep appearing and disappearing on the market, making it hard to adapt analytical methods in a timely manner. In this study we developed a qualitative screening approach for serum samples by means of liquid chromatography quadrupole time-of-flight mass spectrometry. Samples were measured in data-dependent auto-tandem mass spectrometry mode and identified by fragment spectra comparison, retention time and accurate mass. Approximately 500 NPSs, including 195 synthetic cannabinoids, 180 stimulants, 86 hallucinogens, 26 benzodiazepines and 7 others were investigated. Serum samples were fortified to 1 ng/mL and 10 ng/mL concentrations to estimate approximate limits of identification (LOIs). Samples were extracted using solid-phase extraction with non-endcapped C18 material and elution in two consecutive steps. Benzodiazepines were eluted in the first step, while substances of other NPS subclasses were distributed among both extracts. To determine LOIs, both extracts were combined. Ninety-six percentage (470/492) of investigated NPSs were detected in 10 ng/mL samples and 88% (432/492) were detected in 1 ng/mL samples. Stimulants stood out with higher LOIs, possibly due to instability of certain methcathinone derivatives. However, considering relevant blood concentrations, the method provided sufficient sensitivity for stimulants as well as other NPS subclasses. Data-dependent acquisition was proven to provide high sensitivity and reliability when combined with an information-dependent preferred list, without losing its untargeted operation principle. Summarizing, the developed method fulfilled its purpose as a sensitive untargeted screening for serum samples and allows uncomplicated expansion of the spectral library to include thousands of targets.

中文翻译：

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使用液相色谱四极杆飞行时间质谱法对血清中新的精神活性物质进行灵敏筛选

由于可用物质的数量和不断变化的药物市场，新精神活性物质 (NPS) 的分析仍然对许多机构构成挑战。新物质和知名物质在市场上不断出现和消失，使得分析方法难以及时调整。在这项研究中，我们通过液相色谱四极杆飞行时间质谱法开发了一种血清样品的定性筛选方法。样品以数据依赖的自动串联质谱模式进行测量，并通过碎片光谱比较、保留时间和准确质量进行鉴定。研究了大约 500 种 NPS，包括 195 种合成大麻素、180 种兴奋剂、86 种致幻剂、26 种苯二氮卓类药物和其他 7 种。将血清样品加标至 1​​ ng/mL 和 10 ng/mL 浓度，以估计近似鉴定限 (LOI)。使用非封端 C18 材料进行固相萃取，并在两个连续步骤中洗脱样品。苯二氮卓类在第一步被洗脱，而其他 NPS 亚类的物质分布在两种提取物中。为了确定 LOI，将两种提取物合并。在 10 ng/mL 样品中检测到 96% (470/492) 的 NPS，在 1 ng/mL 样品中检测到 88% (432/492)。兴奋剂以较高的 LOI 脱颖而出，可能是由于某些甲卡西酮衍生物的不稳定性。然而，考虑到相关的血液浓度，该方法为兴奋剂以及其他 NPS 亚类提供了足够的灵敏度。事实证明，当与信息相关的首选列表结合使用时，数据相关的采集可提供高灵敏度和可靠性，而不会失去其非目标操作原则。总而言之，所开发的方法实现了其作为对血清样本进行敏感的非靶向筛选的目的，并允许简单地扩展光谱库以包含数千个目标。