A review of microsampling techniques for the analysis of chemical threat agents in biological matrices

Microsampling techniques have revolutionized the collection and analysis of biological samples, offering significant advantages for the detection of chemical threat agents in remote or resource-limited environments. This review explores advancements in microsampling technologies, highlighting the application of established formats including dried blood spots (DBS) and volumetric absorptive microsampling (VAMS) devices for detecting key chemical warfare agent (CWA) biomarkers, such as alkyl methylphosphonic acid (AMPA) metabolites from nerve agents and protein adducts from sulfur mustard. Applications for toxins and potent synthetic opioids like fentanyl are also detailed. The review examines the analytical methods, primarily based on mass spectrometry and chromatography, used for verifying exposure from these low-volume samples. Additionally, it discusses the logistical benefits of microsampling, such as reduced storage requirements and simplified transportation. While established methods provide robust retrospective verification, emerging technologies, such as continuous monitoring biosensors and microneedle arrays, hold the potential to offer promising solutions for real-time detection and diagnosis. Future advancements in microsampling devices and analytical methods will likely expand their applications, enhancing preparedness and response capabilities in chemical threat scenarios.