Forensic Applications of Sandpaper Spray Ionization Mass Spectrometry (SPS-MS): Detection and Chemometric Profiling of Small Molecules for Prohibited Practices

Abstract

The illicit trade of pharmaceuticals and wood presents threats to public health, ecological stability, and global markets. This thesis examines Sandpaper Spray Ionization Mass Spectrometry (SPS-MS) as a rapid, field-deployable technique for direct analysis of solid samples in two distinct forensic applications. (1) SPS-MS was used to detect and identify active pharmaceutical ingredients (APIs) and excipients in pharmaceuticals, assessing product authenticity. (2) SPS-MS was further developed for direct sampling and analysis, obtaining chemical fingerprints for classification and origin tracing of Canadian and Brazilian wood samples, in the context of forestry crimes. Chemometric analysis using PCA revealed clear species differentiation, supporting its use in species-level classification. SPS-MS thus offers a versatile, cost-effective, and operationally simple screening method to supplement current MS techniques. Its portability, minimal reagent use, and possible integration into current analytical workflows make it well-suited for remote or resource-limited settings for frontline testing of fraudulent drugs and trafficked wood.