Understanding the Radian ASAP and Its Functionality
Emily Lee: Radian ASAP, or Rapid Direct Analysis with an Atmospheric Pressure Solids Analysis Probe, is a streamlined mass spectrometry tool designed for rapid, cost-effective drug screening. It simplifies workflows by eliminating the need for chromatography. The process involves introducing a sample through a glass capillary into a corona discharge zone, where heated nitrogen assists ionization. A single quadrupole performs full-scan mass spectrometry, and the results are analyzed using LiveID software that matches spectra to a reference library.
How does it handle complex or novel compounds?
Karen Lau: Radian excels in analyzing difficult mixtures. For example, we’ve identified substances like fentanyl, fluorofentanyl, and xylazine in one scan. The LiveID system is powerful enough to recognize known substances, even in challenging blends, and is particularly effective with emerging drugs like synthetic cannabinoids and nitazenes—areas where traditional methods often struggle.
Is building a reference library difficult?
Emily Lee: Not at all. Waters offers a downloadable drug reference library, and users can expand it by adding their own data. MassLynx raw files are easily converted using tools like ProteoWizard and imported into LiveID. A detailed white paper guides users through the process.
Karen Lau: We’ve created an internal library with 196 compounds, allowing us to reliably compare every result to known standards previously tested on our system.
What about sensitivity and sample overload?
Karen Lau: We’ve occasionally overloaded the system, especially with concentrated oils or liquids, but it still produces interpretable data. Cleaning usually just involves wiping or replacing the capillary. Running a solvent blank before sample analysis helps check for carryover.
Dr. Patrick Sears: In our explosives work, we’ve detected traces like TNT down to femtogram levels, even using surface swabs. For such a compact instrument, the sensitivity is outstanding.
Can Radian ASAP be used outside of drug testing?
Dr. Sears: Definitely. We’ve applied it in food fraud detection (like verifying meat authenticity), undergraduate lab education, and environmental testing (e.g., pesticide detection). It’s simple enough for non-expert users, making it versatile across disciplines.
How suitable is it for high-throughput workflows?
Karen Lau: It’s quite efficient. Processing a blank and a sample takes minutes. For cases involving multiple samples, we can complete full runs within two hours. In fact, we processed nearly 3,000 samples with Radian last year.
What challenges does it address in the field?
Karen Lau: Traditional tests often miss substances in the presence of masking agents like BTMPS. Radian allows us to detect compounds like fentanyl even at low levels. It also helps us identify counterfeit medications and distinguish certain isomers, such as ethylone versus methyl ethylone.
What’s the sample prep process like?
Emily Lee: It’s very straightforward—dissolve the substance in methanol, dip a capillary, and insert it into the source. Data collection begins automatically.
Karen Lau: For complex items like psilocybin chocolates, we perform acid and non-acid extractions to differentiate compounds like psilocybin and its acetylated derivatives.
Any limitations users should keep in mind?
Karen Lau: The absence of chromatographic separation means dominant compounds can suppress others. It struggles to fully separate similar isomers like methylfentanyl vs. fluorofentanyl. Despite that, it’s incredibly valuable for rapid initial screenings.
What maintenance does it require?
Emily Lee: Maintenance is minimal. The “bakeout” feature keeps the capillary clean, and opening the instrument is rarely necessary.
Dr. Sears: We do routine cleaning of the source area, especially in educational settings, but the device has remained stable with little daily upkeep.
