SPME arrow-based extraction for enhanced targeted and untargeted urinary volatilomics

Area of Science:

• Analytical Chemistry
• Environmental Health
• Biomarker Discovery

Background:

• Volatile organic compounds (VOCs) in urine are key biomarkers for health and environmental monitoring.
• Detecting VOCs is challenging due to complex urine matrices and low concentrations.
• Untargeted VOC analysis complicates data interpretation and method development.

Purpose of the Study:

• To develop an advanced method for VOC detection in urine using solid-phase microextraction (SPME) Arrow and gas chromatography-high resolution mass spectrometry (GC-HRMS).
• To optimize the method for both targeted and untargeted urinary volatile organic compound analysis.
• To enhance the identification of novel biomarkers and improve non-invasive diagnostics.

Main Methods:

• Combined SPME Arrow with GC-HRMS for enhanced VOC extraction and detection.
• Utilized a design of experiments (DOE) approach, including univariate and central composite design (CCD), for method optimization.
• Optimized parameters included coating type, urine volume, salt addition, temperature, extraction time, and incubation time.

Main Results:

• The optimized method uses SPME Arrow CAR/PDMS with 2 mL urine, 0.25% NaCl (pH 2) at 53°C for 60 min.
• SPME Arrow demonstrated superior extraction efficiency compared to conventional SPME fibers, detecting more VOCs.
• Successfully identified VOCs, such as p-cymene and p-isopropenyl toluene, associated with tobacco smoke exposure in children's urine samples.

Conclusions:

• The integrated targeted and untargeted approach provides a comprehensive urinary metabolomic profile.
• This dual strategy facilitates precise identification of known compounds and discovery of novel biomarkers.
• The method advances non-invasive diagnostics and environmental health studies by offering deeper insights into metabolic processes and health conditions.