Analysis of Printer Toner Using Double-Shot Pyrolyzer and Peripheral Devices Part 1 : Evolved Gas Analysis (EGA) and Library Search by EGA-MS LIB

Significance of the topic

Printer toners are complex formulations containing polymeric binders, pigments, and additives. Rapid identification of polymer types in toner is essential for quality control, counterfeit detection, and formulation development in the printing industry.

Study Objectives and Overview

This application note demonstrates the use of Double-Shot Pyrolyzer coupled with evolved gas analysis (EGA) and mass spectrometry library search (EGA-MS LIB) as a primary screening tool to identify unknown polymers in a commercial printer toner sample.

Methodology and Instrumentation

The sample (0.5 mg) was placed in an EGA capillary tube (0.15 mm i.d., 2.5 m) and heated from 100 °C to 600 °C at 20 °C/min under helium (50 kPa). Evolved gases were transferred to a GC–MS system with the GC oven held at 300 °C. The pyrolyzer and GC–MS interface were maintained at 320 °C. Mass spectra were recorded from m/z 50 to 400 at 0.1 scans/sec.

Key Results and Discussion

EGA produced a three-stage thermal profile:

• Region A (low temperature): desorption of volatile, low-molecular-weight additives.
• Region B (mid temperature): further desorption of semi-volatile compounds.
• Region C (high temperature): thermal decomposition of polymeric binders.

The mass spectrum from Region C was subjected to library search using EGA-MS LIB. Top matches indicated styrene-based copolymers:

1. Methyl methacrylate-butadiene-styrene copolymer (match quality 90).
2. Styrene-ethylene-butadiene-styrene block copolymer (match quality 86).
3. Styrene-divinylbenzene copolymer (match quality 80).

These results confirm that styrene copolymers are the primary binder components in the toner.

Benefits and Practical Applications

The EGA-MS LIB approach provides a fast, minimally preparative method for initial polymer identification in complex matrices. It streamlines sample screening in QA/QC laboratories, counterfeit analysis, and R&D of new toner formulations.

Instrumentation Used

• Double-Shot Pyrolyzer with EGA capillary tube (UADTM-2.5N).
• Gas chromatograph (300 °C isothermal) with pyrolysis interface.
• Mass spectrometer (m/z 50–400, 0.1 scans/sec).

Future Trends and Potential Applications

Advances in EGA-MS library coverage and coupling with high-resolution MS will enhance polymer identification accuracy. Integration with chemometric analysis and real-time monitoring could expand applications to field screening, forensic analysis, and online process control in polymer manufacturing.

Conclusion

The combination of EGA and library search by EGA-MS LIB using a Double-Shot Pyrolyzer offers a robust primary screening technique for polymer identification in printer toners. It effectively differentiates polymeric binders from additives and facilitates informed decision-making in various industrial and research settings.