Rapid Detection of Trace Toxicants in Blood Using Thermal Desorption Coupled to Continuous Atmospheric Pressure Interfaced Ion Trap Mass Spectrometry

Acute poisoning has become the fifth leading cause of death among urban residents in China. A pivotal challenge in clinic is the rapid and precise identification of toxicants to guide targeted detoxification strategies. Conventional laboratory-based techniques, such as gas chromatography-mass spectrometry (GC-MS), have the advantages of high sensitivity and high selectivity, but often require complex sample preparation, specialized operators, and prolonged turnaround times, rendering them unsuitable for rapid on-site detection. Miniaturized ion trap mass spectrometers have characteristics of high working pressure, tandem-in-time mass spectrometry functions, and field-portable design, which represent a promising approach for rapid on-site detection and hold significant potential for supporting the diagnosis and treatment of acute poisoning. In this study, a novel analytical platform integrating thermal desorption (TD) with a continuous atmospheric pressure interfaced ion trap mass spectrometry (CAPI-ITMS) was developed to rapidly and accurately detect common toxicants in blood matrices. The results demonstrated that this instrument exhibited excellent detection capabilities for three categories (nine types) of common toxicants, including pesticides, sedative hypnotics, and therapeutic drugs. To improve the accuracy of qualitative identification of toxicants in blood, the floating DC was adjusted to trigger collision-induced dissociation and obtain characteristic fragment ions of toxicants. In addition, combined with simple and efficient liquid-liquid extraction, the rapid and accurate detection of toxicants in blood was achieved within 2 min. The instrument exhibited good stability, with the relative standard deviation of 6.41% over 100 repeated tests. Based on a signal-to-noise ratio of 3, the detection limit of toxins in blood is in the range of 1.3-3.9 µg/L. The thermal desorption-continuous atmospheric pressure interfaced ion trap mass spectrometer not only provides critical guidance for targeted treatment of acute poisoning patients through precise qualitative analysis, but also enables the assessment of treatment effectiveness through quantitative analysis of the toxic substances. Given its cost-effectiveness and ease of operation, this instrument holds significant potential for widespread application in county-level hospitals with limited analytical resources, enabling rapid diagnosis of acute poisoning, real-time monitoring of drug levels, and disease detection. This approach provides doctors with precise and timely information to improve patient care quality and treatment efficiency.