Analysis of MOSH/MOAH on paper using OPTIC Multimode Inlet with Advanced Liner exchanging with Capping and Decapping Station

Significance of the Topic

Mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) can migrate from recycled paper packaging into food, posing potential health risks. Growing regulatory pressure and consumer safety concerns drive the need for reliable, efficient analytical methods to screen paper materials for these contaminants.

Objectives and Study Overview

This application note demonstrates a fully automated thermal desorption approach using an OPTIC-4 multimode inlet with liner exchange and a capping/decapping station. The aim is to simplify sample preparation and improve throughput for MOSH/MOAH analysis on paper substrates.

Methodology

Five-centimeter-by-two-centimeter paper pieces containing MOSH or MOAH residues were placed directly into single-neck liners, capped, and loaded onto an autosampler. The thermal desorption protocol was controlled by expert software, transferring volatiles into a GC column for separation and subsequent MS detection.

Instrumentation

• GC Inlet: OPTIC-4 Multimode Inlet with liner exchange and capping/decapping station
• Liner Type: Single-necked liner (part 2414-1003)
• GC-MS System: Shimadzu QP2010
• Column: GL Sciences InertCap 5 MS/Sil, 0.25 mm × 30 m, 0.25 μm film

Analytical Conditions

Thermal desorption reached 175 °C after a 40 °C initial hold, with controlled carrier flow and split parameters to optimize transfer efficiency. The GC oven ramped from 40 °C to 325 °C at 20 °C/min with a final hold of 15 minutes. MS detection operated in scan mode (m/z 50–1000) with an ion source at 200 °C and transfer line at 250 °C.

Main Results and Discussion

Distinct hydrocarbon profiles were observed for each paper sample. Paper 1 yielded peaks corresponding to heptadecane and 2-hexyl-1-octanol, indicative of MOSH and fatty alcohol residues. Paper 2 showed 3-dodecane and tritetracontane signals, reflecting a different mineral oil composition. Overlaying chromatograms confirmed clear differentiation between MOSH and MOAH-containing substrates.

Practical Benefits and Applications

• Eliminates solvent extraction and manual sample prep, reducing contamination risk.
• Automated liner exchange and capping improve throughput for routine screening.
• Applicable in quality control labs for compliance with food packaging regulations.

Future Trends and Potential Applications

Advances may include high-resolution mass spectrometry for enhanced MOAH characterization, miniaturized inlet designs for rapid screening, and integration of data analytics to fingerprint complex matrices. Expansion to other packaging types and regulatory frameworks will further drive method adoption.

Conclusion

The automated OPTIC-4 thermal desorption workflow offers a streamlined, reproducible solution for MOSH/MOAH analysis on paper. It combines minimal sample handling with robust GC-MS detection to support regulatory compliance and consumer safety.

Reference

No additional literature references were provided in the application note.