711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, OH 45433, USA.
UES Incorporation, Dayton, OH 45432, USA.
Biosensors (Basel). 2023 Jun 8;13(6):635. doi: 10.3390/bios13060635.
The current COVID-19 pandemic has highlighted the power, speed, and simplicity of point-of-care (POC) diagnostics. POC diagnostics are available for a wide range of targets, including both drugs of abuse as well as performance-enhancing drugs. For pharmacological monitoring, minimally invasive fluids such as urine and saliva are commonly sampled. However, false positives or negatives caused by interfering agents excreted in these matrices may confound results. For example, false positives have, in most cases, prevented the use of POC diagnostics for pharmacological agent detection; the consequence is that centralized labs are instead tasked to perform these screenings, resulting in significant delays between sampling and testing. Thus, a rapid, simple, and inexpensive methodology for sample purification is required for the POC to reach a field-deployable tool for the pharmacological human health and performance assessments. Buffer exchange is a simple, rapid approach to remove interfering agents, but has traditionally been difficult to perform on small pharmacological molecules. Therefore, in this communication, we use salbutamol, a performance-enhancing drug, as a case example to demonstrate the efficacy of ion-exchange chromatography as a technique to perform buffer exchange for charged pharmacological agents. This manuscript demonstrates the efficacy of this technique leveraging a commercial spin column to remove interfering agents found in simulant urines, such as proteins, creatinine, and urea, while retaining salbutamol. The utility and efficacy of the method was then confirmed in actual saliva samples. The eluent was then collected and run on the lateral flow assays (LFAs), improving the reported limit of detection by over 5× (new lower limit of detection of 10 ppb compared to reported 60 ppb by the manufacturer) while simultaneously removing noise due to background interfering agents.
当前的 COVID-19 大流行凸显了即时检测（POC）诊断的强大、快速和简便。POC 诊断可用于广泛的目标，包括药物滥用和兴奋剂。对于药理学监测，通常采集尿液和唾液等微创体液样本。然而，这些基质中排泄的干扰剂可能会导致假阳性或假阴性，从而混淆结果。例如，在大多数情况下，假阳性阻止了 POC 诊断用于药物检测；其结果是，中央实验室负责进行这些筛查，导致采样和检测之间存在显著延迟。因此，需要一种快速、简单且廉价的样品净化方法，以使 POC 成为用于人类健康和性能评估的现场可部署工具。缓冲液交换是一种去除干扰剂的简单、快速方法，但传统上难以对小分子药物进行操作。因此，在本通讯中，我们以沙丁胺醇（一种兴奋剂）为例，展示离子交换色谱作为一种用于带电荷药物的缓冲液交换技术的功效。本文利用商业离心柱证明了该技术去除模拟尿液中蛋白质、肌酸酐和尿素等干扰物的功效，同时保留沙丁胺醇。然后，在实际唾液样本中验证了该方法的实用性和功效。然后收集洗脱液并在侧流测定法（LFA）上进行分析，将报告的检测限提高了 5 倍以上（新的检测限为 10 ppb，而制造商报告的检测限为 60 ppb），同时消除了背景干扰剂引起的噪声。
