Troubleshooting for Morphine Interference in a Method Analyzing Drugs of Abuse in Exhaled Breath Malin Johansson (Presenter) Karolinska University Hospital Laboratory

Authors: Malin Johansson (1), Shahid Ullah (2), Nikolai Stephanson (3), Gerd Ackehed (4)
Karolinska University Hospital Laboratory

Aerosol particles in exhaled breath containing organic substances are collected using a specific collector, called Breath Explore. After sample preparation the aerosol particles are analyzed by a LC - triple quadrupole mass spectrometer. Method was used for analysis of 16 drugs of abuse. The chromatography of morphine was randomly affected by an interference. Preliminary investigation suggests, polyglycols together with evaporation step, may be responsible for the interference. It seems that evaporation of sample extract is a critical step for morphine analysis. Further investigation with more conclusive results will be presented at the conference.

Problem

The chromatography of morphine is affected by an interference. The interference appears randomly in some sample and not in others.

Method Information

•Sample preparation: Extraction from collector to acidified methanol solution, evaporation to dryness, reconstitution in methanol and ammonia

•Ion source type: H-ESI

•Instrument: Thermo LC-MS/MS Dionex Ultimate 3000 UHPLC-TSQ QUANTIVA

•Mobile phase A: 4 mmol/L Ammonium Formate in 0.05% ammonia in H2O

•Mobile phase B: 4 mmol/L Ammonium Formate with 0.05% ammonia in methanol

•Gradient: 5 minutes with 0.650 mL/min flow rate

•Column: Phenyl C18 2.1x100, 1.7 µm

•Column oven temperature: 65 ᵒC

•Injection volume: 2 µL

•Acquisition: Quantitative SRM

Troubleshooting Steps

The LC was ruled out after several tests. The different steps of sample preparation, sample collector, extraction solvents, and evaporation were investigated.

Outcome

The presence of polyglycols and the evaporation step during sample preparation are the most likely causes of the interference, however, the source of the interference is still under investigation.