INTip Size Exclusion Chromatography for Analysis of Drugs of Abuse in Oral Fluid
ASMS 2025 Poster Presentation
Size Matters in Sample Preparation – Using SEC Tips for LC/MS Analysis of Comprehensive Drugs in Oral Fluid
Thursday
Poster# ThP402
Abstract
Many LC/MS methods require comprehensive analysis, which is contrary to conventional sample preparation. Instead of separating compounds based on chemical differences, it is possible to remove interferences such as phospholipids, surfactants, and proteins by size exclusion chromatography (SEC).
In this poster, we demonstrate the utility of 300μL SEC Tips to isolate drugs from oral fluid buffer solutions. The SEC Tips are dry initially, and are readily swollen into a gel by simple capillary action – a patent-pending method known as INTip™ Swelling. The pores of the SEC resin are too small for the larger compounds such as surfactants and phospholipids, so these interferences pass through the resin quickly and are readily separated from common drugs and metabolites. We present limits of detection that show the usefulness of this method for meeting the suggested guidelines for oral fluid drug testing.
Method
| 1 | Material | 300 µL SEC tips manual format (also available for Hamilton Robotics platforms) |
|---|---|---|
| 2 | Patent-pending INTip Swelling | Allow to swell via capillary action. |
| 3 | Equilibrate | Add PBS. Allow to gravity flow. |
| 4 | Load Sample | Load desired sample volume. Allow to gravity to waste. Image shows dye-stained proteins. |
| 5 | Remove Interferents | Add solvent. Allow to gravity flow to waste. Image shows purple proteins removed in well |
| 6 | Collect | Add solvent. Collect for direct injection into LC/MS. Image shows yellow protein in collection well |
