Semivolatiles CLP Method - Rtx®-5MS

Significance of the Topic

Semivolatile organic compounds, including phenols, chlorinated hydrocarbons, nitroaromatics, phthalates and polycyclic aromatic hydrocarbons (PAHs), act as critical environmental pollutants. Accurate identification and quantification of these analytes are essential for water, soil and air quality monitoring, regulatory compliance and risk assessment.

Objectives and Study Overview

The study aimed to evaluate a comprehensive method for separating 80 semivolatile compounds in a single gas chromatography–mass spectrometry (GC–MS) run. It focused on establishing reproducible retention times and demonstrating the method’s suitability for routine environmental analysis and quality control.

Methodology

The semivolatile standard mixture was analyzed on a 30 m × 0.25 mm ID GC column coated with 0.25 µm Rtx-5MS (5% diphenyl phase). An 80 ng splitless injection was performed. The oven program started at 40 °C (2 min), ramped to 245 °C at 25 °C/min, then to 330 °C at 6 °C/min with a 5 min hold. Helium was used as the carrier gas at 1.0 mL/min constant flow. Injector temperature was set to 300 °C and MS detector to 280 °C. Full‐scan MS detection spanned 35–550 amu.

Used Instrumentation

• GC column: 30 m × 0.25 mm ID, 0.25 µm film thickness, Rtx-5MS (5% diphenyl, cat. #12623)
• Injection: 80 ng splitless at 300 °C
• Carrier gas: Helium, 1.0 mL/min constant flow
• Oven program: 40 °C (2 min) → 245 °C @ 25 °C/min → 330 °C @ 6 °C/min (5 min hold)
• MS detection: Full‐scan 35–550 amu, detector at 280 °C

Main Results and Discussion

The method achieved baseline separation for all 80 target compounds, with retention times ranging from 4.65 min (2-fluorophenol) to 20.81 min (benzo[ghi]perylene). Monochlorophenols eluted between 5.6–6.0 min, chlorobenzenes at 5.8–6.3 min, and higher molecular weight PAHs between 10–20 min. Sharp peak shapes and adequate resolution across a wide volatility and polarity spectrum demonstrate the column’s capacity to handle complex environmental samples.

Benefits and Practical Applications

This streamlined GC–MS method provides reliable, single‐run analysis for key environmental semivolatiles. Its broad analyte coverage supports regulatory compliance testing, quality assurance in drinking water and soil laboratories, and routine monitoring of industrial emissions and effluents.

Future Trends and Potential Applications

Emerging developments include accelerated temperature programs, shorter columns with advanced stationary phases for high‐throughput analysis, and integration with high‐resolution mass spectrometry for enhanced selectivity. Automated data processing and AI‐driven pattern recognition are expected to further improve semivolatile profiling and environmental risk assessment.

Conclusion

The validated method using an Rtx-5MS column and optimized GC–MS conditions delivers reproducible retention data and effective separation of a broad semivolatile compound range. It is well suited for environmental monitoring and compliance laboratories seeking robust, high-quality analyses.