GERSTEL Sample Prep Solution 3-MCPD

Importance of the topic

Edible oil refining can inadvertently produce 2-MCPD, 3-MCPD and glycidyl fatty acid esters under high-temperature vacuum steam deodorization when chlorides are present. These contaminants pose potential health risks and are subject to regulatory limits. Developing robust analytical workflows to detect and quantify these compounds at trace levels is critical for consumer safety, quality assurance and compliance with international standards.

Objectives and overview

This work presents an automated sample preparation solution for the indirect determination of 3-MCPD, 2-MCPD and glycidol esters in fats and oils. The approach closely follows the unified DGF C-VI 18 (10), ISO 18363-1 and AOCS Cd 29c-13 methods while reducing solvent volumes and hands-on time. The goal is to achieve high sensitivity, reproducibility and throughput using an integrated robotic platform coupled to GC/MS.

Methodology and instrumentation

The workflow is implemented on a GERSTEL MultiPurpose Sampler (MPS) Dual Head system equipped with quickMIX and mVAP modules. Key steps include:

• Manual loading of sample (100 mg) and optionally a drying vial with sodium sulfate
• Automated liquid handling: addition of MTBE, internal standard, methanol/NaOH for ester cleavage, followed by acidification with NaCl and NaBr solutions
• Liquid-liquid extractions with n-hexane and MTBE/ethyl acetate
• Drying, evaporation to dryness under vacuum at 50 °C and derivatization with phenylboronic acid
• Reconstitution in isooctane and GC/MS or GC/MS/MS analysis

The evaporation step within the GERSTEL mVAP ensures concentration of analytes to reach low limits of detection using a single quadrupole MSD. The PrepAhead scheduler enables parallel processing to achieve up to 24 samples processed and 48 GC/MS runs in 24 hours.

Key results and discussion

Performance evaluation, as detailed in GERSTEL AppNote 191, demonstrates strong agreement between the automated protocol and traditional manual procedures. The method shows excellent linearity, repeatability and recovery across various edible oil matrices. Automation eliminates operator variability, reduces solvent usage and enhances laboratory throughput.

Benefits and practical applications

The fully automated solution offers:

• Strict compliance with ISO, AOCS and DGF standard methods
• Reduced manual intervention and error
• Lower solvent consumption and waste generation
• Improved GC/MS system stability through removal of excess derivatization reagent
• High sample throughput suitable for routine quality control and regulatory testing

This approach is directly applicable in food analysis laboratories, oil refineries quality departments and contract testing services.

Future trends and opportunities

Advances may include integration with high-resolution mass spectrometry for enhanced selectivity, miniaturization of extraction steps to further reduce solvent volumes, and expanded automation to cover upstream refining monitoring. Coupling real-time data analytics and laboratory information management systems (LIMS) can drive proactive process optimization and risk mitigation.

Conclusion

The GERSTEL automated sample preparation solution streamlines the indirect determination of MCPD and glycidyl esters in edible oils. By fully automating a unified standard method workflow, it delivers sensitive, reproducible results with high throughput and minimal manual effort. The protocol supports food safety objectives and regulatory compliance in the fats and oils sector.

Reference

Lucas D.; Hoffmann A.; Gil C. Fully Automated Determination of 3-MCPD and Glycidol in Edible Oils by GC/MS Based on the Commonly Used Methods ISO 18363-1, AOCS Cd 29c-13, and DGF C-VI 18 (10), GERSTEL AppNote No. 191, 2017.