Automated Analysis of the Preservative Compound HDO in Impregnated Wood by Direct Thermal Desorption-GC-MS Using the Focus-DTD Robotic Sampler

Significance of the Topic

The analysis of preservative compounds in impregnated wood is essential for ensuring material durability, environmental compliance and quality control in the forestry and wood-treatment industries. Automated, solvent-free approaches reduce sample handling, increase throughput and minimize variability.

Objectives and Study Overview

This application note presents a fully automated method for the direct thermal desorption–GC–MS analysis of the preservative compound HDO (hydroxydodecyl diphenyl phosphate) in wood samples. The goal was to demonstrate rapid, no-prep quantification of HDO in solid wood matrices using the Focus-DTD robotic sampler coupled to standard GC–MS instrumentation.

Methodology

Wood splinters impregnated with known levels of HDO are loaded into inert Sepliners, which are placed in an autosampler tray. The robotic sampler then:

• Picks each Sepliner and inserts it into the Optic 2-200 programmable GC injector,
• Thermally desorbs HDO directly from the wood at controlled temperatures,
• Transfers analytes to the GC column for separation and MS detection in full-scan mode.

Instrumentation

• Optic 2-200 programmable injector
• Focus Direct-TD automated thermal desorber with robotic sampling
• Agilent 6890 gas chromatograph
• HP5-MS capillary column (25 m × 0.25 mm × 0.25 µm)
• Agilent 5973N mass selective detector

Key Results and Discussion

The method yielded a distinct HDO peak at 4.466 min in a full-scan chromatogram of a 10 mg pine sample with 56 ppm HDO. Characteristic mass fragments (m/z 55, 80, 41, 67, 81, 114) confirmed compound identity. Signal-to-noise ratios and peak shapes indicated excellent sensitivity and minimal matrix interference, supporting its suitability for routine quality control.

Benefits and Practical Applications

This automated DTD–GC–MS workflow offers:

• No solvent or complex sample preparation,
• High sample throughput with minimal human intervention,
• Reproducible results and reduced contamination risk,
• Easy integration into existing GC–MS laboratories for preservative monitoring.

Future Trends and Potential Applications

Advances may include multiplexed thermal desorbers for simultaneous multi-analyte screening, miniaturized field-portable systems for onsite wood analysis, and AI-driven data processing to enhance result accuracy and speed. Integration with laboratory information management systems (LIMS) will further streamline QA/QC operations.

Conclusion

The combination of direct thermal desorption with a robotic sampler and GC–MS provides a robust, efficient and environmentally friendly solution for the automated analysis of HDO in wood. This approach delivers reliable quantification with minimal preparation, making it ideal for industrial and research laboratories.