Analyzing UV-328 and Dechlorane Plus in Plastic by Pyrolyzer/Thermal Desorption-GC-MS

Significance of the Topic

Screening for UV absorbers and fluorinated flame retardants in plastic materials is critical for environmental safety and regulatory compliance. UV-328 and dechlorane plus are persistent organic pollutants that accumulate in ecosystems and pose human health risks. A rapid, solvent-free method supports industry and laboratories in quality control and adherence to international conventions.

Study Objectives and Overview

This study develops and evaluates a pyrolyzer thermal desorption–GC-MS approach for simultaneous detection of UV-328 and dechlorane plus in various polymers. The goal is to replace time-consuming solvent extraction with a direct, automated screening technique and to validate its performance on standard and real samples.

Methodology and Instrumentation

Polymer samples spiked with defined concentrations of UV-328 and dechlorane plus were introduced into a multi shot pyrolyzer with thermal desorption. A GCMS QP 2020 NX system performed chromatographic separation on a polar column with an integrated guard. Key temperature programs included ramping the pyrolyzer from 200 C to 340 C in two stages and the GC oven from 80 C to 320 C. Helium carrier gas and split injection were used. Mass spectrometric detection combined scan and selected ion monitoring modes focusing on ions m/z 351.2 for UV-328 and m/z 271.8 for dechlorane plus.

Instrumentation Used

• Frontier Laboratories EGA PY 3030D multi shot pyrolyzer with AS 1020E autosampler
• Shimadzu GCMS QP 2020 NX
• SH-1MS capillary column with integrated guard (length 15 m inner diameter 0.25 mm film thickness 0.1 um plus 2 m guard)

Key Results and Discussion

Calibration curves in a PVC matrix from 0 to 2000 mg/kg exhibited linearity with R2 above 0.998. Repeatability at 1000 mg/kg showed relative standard deviations below 5 percent. Method detection limits were under 50 mg/kg for both compounds. Recovery tests in PVC, PS, ABS and PET yielded average recoveries of 104–111 percent for UV-328 and 96–134 percent for dechlorane plus. Analysis of a liquid crystal module and coated wire confirmed the presence of UV-328 in the module’s second layer and dechlorane plus in the wire coating, demonstrating effective screening without solvent extraction.

Benefits and Practical Applications

• Eliminates solvent extraction and reduces analysis time
• Minimizes organic solvent usage and analyst intervention
• Enables simultaneous qualitative and quantitative screening with a single run
• Applicable to diverse plastics for regulatory and quality control testing

Future Trends and Applications

Advances may include coupling pyrolysis desorption with high-resolution and ambient mass spectrometry to expand analyte scope and improve sensitivity. Integration into automated workflows and real-time monitoring could further increase throughput and applicability to emerging persistent pollutants.

Conclusion

The pyrolyzer thermal desorption–GC-MS method offers a rapid, solvent-free screening of UV-328 and dechlorane plus in plastics. High linearity, good repeatability, low detection limits and reliable recoveries validate its suitability for routine compliance and quality assurance without elaborate sample preparation.