Fully Automated Analysis of Doping Substances in Equine Urine by Disposable Pipette Extraction (DPX) coupled to GC/QqQ-MS

Význam tématu

The use of doping substances in equine sports presents complex analytical challenges due to low allowed concentrations and complex urine matrices.
Ensuring reliable detection requires robust sample cleanup and sensitive detection.

Cíle a přehled studie / článku

This article describes an automated workflow for extraction and GC triple quadrupole MS analysis of equine urine for selected doping agents.
The method employs disposable pipette extraction DPX coupled to large volume injection LVI and QqQ MS detection.
It aims to deliver low detection limits and high throughput.

Použitá instrumentace

• GERSTEL MultiPurpose Sampler MPS dual head with DPX option
• GERSTEL Cooled Injection System PTV inlet with Automated Liner EXchange ALEX
• Agilent 7890 GC coupled to 7000 QqQ or 5975 single quad MS
• Cryo trap system for two dimensional GC fraction focusing

Použitá metodika a instrumentace

• DPX WAX sorbent in pipette tips for dispersive SPE extraction
• Tip conditioning with methanol water sequence and alkaline sample pretreatment
• Turbulent mixing via aspirating air and repeated extraction cycles
• On tip washing with water and elution with acetone
• Large volume injection up to 8 uL to improve sensitivity
• 2D heart cutting GC SIM for limited analytes or SRM QqQ for full panel

Hlavní výsledky a diskuse

The DPX WAX phase provided efficient removal of phenolic matrix components and improved analyte recovery.
Conditioning with 500 uL methanol and 2 mL water gave best extraction.
Washing with 2 mL water ensured minimal matrix carryover.
Elution with acetone yielded clean extracts.
Matrix induced signal enhancement was observed for large volume injections.
SRM on QqQ MS delivered detection limits between 0.1 and 10 ng/mL.
2D GC SIM and single quadrupole SIM modes showed lower sensitivity and selectivity.
The method achieved good linearity R2>0.997 and recoveries above 85 for most compounds.

Přínosy a praktické využití metody

• Fully automated sample prep overlapping with GC run increases throughput
• Low quantification limits suitable for regulatory testing
• Reduced human error and improved reproducibility
• Compatible with both GC MS and LC MS workflows for broad analyte scope

Budoucí trendy a možnosti využití

The DPX workflow can be extended to other matrices and analytes including polar substances after derivatization.
Integration with LC QqQ MS offers alternative screening paths.
Advances in sorbent chemistry and automation will further reduce analysis time.
Online conjugate cleavage and derivatization could expand method scope.

Závěr

The fully automated DPX LVI GC QqQ MS workflow delivers a rugged high throughput method for equine urine doping analysis.
It combines efficient matrix cleanup low detection limits and robust performance.
This approach supports regulatory requirements and can be adapted to future analytical challenges.

Reference

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