Sub 1 mg/kg (1 ppm) Detection of Carbon Disulfide with the Polyarc System

Importance of the Topic

The ability to detect carbon disulfide at subppm levels is critical for protecting human health and ensuring product safety. Due to its neurotoxicity and potential organ damage, reliable monitoring in environmental, pharmaceutical, and industrial settings is essential.

Objectives and Study Overview

This application note demonstrates a low-cost approach for trace analysis of carbon disulfide using the Polyarc reactor in series with a flame ionization detector. The goal is to achieve a minimum detection limit below 1 mg/kg through catalytic conversion of CS2 to methane.

Methodology

Samples of carbon disulfide were prepared by serial dilution in 1-propanol to yield 1.24 mg/kg solutions. An Agilent 7890A gas chromatograph fitted with a split/splitless inlet and a DB-5 UI capillary column was used. The Polyarc reactor, maintained at 293 C with controlled hydrogen and air flow, catalyzed conversion of CS2 to methane prior to detection by FID. Helium was used as carrier and makeup gas under high flow to sharpen peak widths to approximately one second.

Použitá instrumentace

• Gas chromatograph Agilent 7890A with split/splitless inlet
• DB-5 UI capillary column (30 m × 0.25 mm × 1 μm)
• Polyarc reactor (ARC PA-RRC-A02) operated at 293 C
• Flame ionization detector with hydrogen, air, and helium makeup gas
• Agilent 5973 mass spectrometer for comparative analysis

Key Results and Discussion

Chromatograms of 1.24 mg/kg CS2 in 1-propanol exhibited sharp peaks with retention around 1.25 minutes and a signal to noise ratio of 27. Based on a three times noise criterion, the minimum detection limit was calculated as 0.14 mg/kg. The Polyarc conversion enabled FID response for CS2 by generating methane, overcoming the lack of C-H bonds in the native molecule.

Benefits and Practical Applications

This method provides a cost effective alternative to mass spectrometric detection for CS2, eliminating the need for a second detector. It is well suited for routine monitoring in environmental testing, workplace safety, and quality control in pharmaceutical manufacturing.

Future Trends and Applications

Adaptation of this approach to other solvent systems and volatile sulfur compounds can broaden its applicability. Integration with online sampling and automation may further enhance analytical throughput and real-time monitoring capabilities.

Conclusion

The Polyarc reactor combined with FID offers a straightforward, sensitive, and economical solution for detecting carbon disulfide at subppm levels by catalytically converting it to methane for ionization detection.

Reference

Application Note Sub 1 mg/kg Detection of Carbon Disulfide with the Polyarc System Activated Research Company 2017