PCB and Dioxin Analysis Automated Sample Clean-up

Importance of the topic

Persistent organic pollutants such as PCBs and dioxins pose serious health and environmental risks due to their toxicity, persistence, and bioaccumulation. Accurate, reliable, and high-throughput analytical methods are essential for regulatory compliance and environmental monitoring.

Objectives and overview of the article

This article presents the DEXTech portfolio of automated sample clean-up systems designed for PCB and dioxin analysis. It outlines the development milestones, key features, and application scenarios of DEXTech Pure, DEXTech Heat, DEXTech 16, and the D-EVA concentrator to meet diverse laboratory needs from small-scale to high-volume operations.

Methodology and used instrumentation

Instrumentation:

• DEXTech Pure: Single-sample clean-up with a three-column configuration (acidic silica, aluminium-oxide, carbon), click-in ready-to-use glass columns, pre-installed EPA-compliant methods
• DEXTech Heat: Heated workflow extension for matrices that solidify at ambient temperature, ensuring homogenous reagent distribution and clog-free processing
• DEXTech 16: Fully automated sequential clean-up of up to 16 samples with a column carousel, closed-vial autosampler, touchscreen control, and unattended 24/7 operation
• D-EVA: Parallel rotational vacuum concentrator for up to 26 samples, with automatic stop sensor, cold trap for solvent recovery, and direct transfer into GC vial inserts

Workflow steps:

1. Load sample vials into the autosampler
2. Click-in columns into the column tower or carousel
3. Pressurize and rinse for quantitative sample transfer
4. Execute automated clean-up and fractionation according to selected method
5. Collect PCB and dioxin fractions in closed vials
6. Optionally concentrate fractions using D-EVA

Main results and discussion

Automated DEXTech systems deliver reproducible, high-quality clean-up with clear chromatographic signals, sharp peak separation, and excellent analyte recoveries. DEXTech Pure ensures reliable fractionation of PCB and dioxin analytes. DEXTech 16 expands throughput capability, enabling unattended processing of 16 samples without cross-contamination. The D-EVA concentrator consistently reduces fraction volumes to low microliter levels with minimal analyte loss.

Benefits and practical applications

• Enhanced laboratory efficiency by reducing manual handling and freeing analysts for higher-value tasks
• Consistent, reproducible data supporting method validation and regulatory compliance
• Scalable solutions from single-sample analysis to high-throughput sequential processing
• Compliance with US EPA and international regulations for PCB and dioxin analysis
• Robust safety features including closed-vial sampling, leak and pressure sensors, and flushing steps to prevent cross-contamination
• Adaptable workflows with heated units for challenging matrices and flexible method parameterization

Future trends and potential applications

Future developments may include integration with online mass spectrometry for seamless end-to-end analysis, new sorbent chemistries for emerging contaminants, and IoT-enabled remote monitoring for preventative maintenance. Miniaturization and advanced automation will further streamline workflows and expand applications in environmental, food, and clinical laboratories.

Conclusion

The DEXTech family of automated clean-up systems, combined with the D-EVA concentrator, offers a comprehensive platform for efficient, reliable, and high-throughput PCB and dioxin analysis. These solutions enhance laboratory productivity, ensure reproducibility, and support regulatory adherence, driving advances in persistent organic pollutant monitoring.