Rapid Screening of Illicit Drugs from Biofluid via Dried Blood/Urine Spot and Ultrasonic Desorption-Assisted Low-Temperature Arc Plasma Ionization Mass Spectrometry

A novel method for rapid and sensitive illicit drug screening in biofluids has been developed by employing a paper-based sample collection coupled with ultrasonic desorption-assisted low-temperature plasma ionization mass spectrometry (PBS-LTPI-MS). For optimization, key experimental parameters, such as geometry coordinates, angle, and plasma intensity, were fine-tuned using ketamine as the representative analyte. The redissolution process, which encompasses the use of organic solvents and sample collection paper, underwent an evaluation to establish conditions conducive to efficient ionization. The proposed method demonstrated excellent analytical performance, with linear ranges exceeding <i>R</i>² > 0.99, limits of detection ranging from 10 to 20 ng mL^-1, and impressive recovery rates exceeding 91.16% in complex biofluid matrixes. Spiked recovery experiments revealed strong matrix tolerance and reliable performance, even in the presence of illicit drug mixtures. The robustness of the sampling device under varying storage temperatures and durations further confirmed the method's suitability for point-of-care testing and large-scale sample collection. With the ability to analyze samples within a mere 3 s, high-throughput potential, and environmental robustness, this method stands out as an invaluable instrument for rapid illicit drug screening and forensic analysis.