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Abstract：
Direct coupling of sample preparation with mass spectrometry (MS) can speed up analysis, enabling faster decision-making. In such combinations, where the analysis time is mainly defined by the extraction procedure, magnetic dispersive solid-phase extraction emerges as a relevant technique because of its rapid workflow. The dispersion and retrieval of the magnetic sorbent are typically uncoupled stages, thus reducing the potential simplicity. Stir bar sorptive dispersive microextraction (SBSDME) is a novel technique that integrates both stages into a single device. Its miniaturization (mSBSDME) makes it more portable and compatible with low-availability samples. This article reports the direct combination of mSBSDME and MS using a needle-based electrospray ionization (NESI) emitter as the interface. This combination is applied to determine tetrahydrocannabinol in saliva samples, a relevant societal problem if the global consumption rates of cannabis are considered. The coupling requires only the transference of the magnet (containing the sorbent and the isolated analyte) from the mSBSDME to the hub of a hypodermic needle, where the online elution occurs. The application of 5 kV on the needle forms an electrospray on its tip, transferring the ionized analyte to the MS inlet. The excellent performance of mSBSDME-NESI-MS/MS relies on the sensitivity (limits of detection as low as 2.25 ng mL-1), the precision (relative standard deviation lower than 15%), and the accuracy (relative recoveries ranged from 87 to 127%) obtained. According to the results, the mSBSDME-NESI-MS/MS technique promises faster and more efficient chemical analysis in MS-based applications.
摘要：
样品制备与质谱（MS）的直接耦合可以加快分析，实现更快的决策。在这样的组合中,其中分析时间主要由提取程序定义，磁性分散固相萃取由于其快速的工作流程而成为相关技术。磁性吸附剂的分散和回收通常是非耦合阶段，从而降低了潜在的简单性。搅拌棒吸附分散微萃取（SBSDME）是一种将两个阶段集成到单个设备中的新颖技术。它的小型化（mSBSDME）使其更便携，与低可用性样品兼容。本文报道了使用基于针的电喷雾电离（NESI）发射器作为界面的mSBSDME和MS的直接组合。该组合用于测定唾液样品中的四氢大麻酚，如果考虑到大麻的全球消费率，这是一个相关的社会问题。耦合仅需要将磁体（包含吸附剂和分离的分析物）从mSBSDME转移到皮下注射针的毂，发生在线洗脱的地方。在针头上施加5kV在其尖端形成电喷雾，将电离分析物转移到MS入口。mSBSDME-NESI-MS/MS的优异性能依赖于灵敏度（检测限低至2.25ngmL-1），精密度(相对标准偏差低于15%)，获得的准确性（相对回收率为87％至127％）。根据结果,mSBSDME-NESI-MS/MS技术承诺在基于MS的应用中更快，更有效的化学分析。
