Shimadzu Food Safety Management Data Book

Significance of Topic

Gas chromatography coupled with flame thermionic detection (FTD) and electron capture detection (ECD) enables simultaneous screening of a broad range of pesticide residues in food commodities. The high separation efficiency of capillary columns is essential for meeting stringent regulatory limits and for high-throughput quality control in food safety labs.

Objectives and Overview of the Study

This study evaluates the separation performance and retention characteristics of 124 pesticides, including organochlorines, organophosphorus, nitrogen-containing, and carbamate pesticides, using four different capillary GC columns (DB-1, DB-5, DB-1301, DB-17) with FTD and ECD detection modes. The goal is to establish relative retention time libraries for rapid screening and to assess column selectivity.

Used Instrumentation

• GC System: GC-17AAF with AOC-20i autosampler
• Columns: DB-1, DB-5, DB-1301, DB-17 (30 m × 0.25 mm I.D., 0.25 µm film)
• Detectors: Flame Thermionic Detector (FTD-17), Electron Capture Detector (ECD-17)
• Carrier Gas: Helium at 150 kPa
• Injection: High pressure splitless at 300 kPa for 1 min, injection volume 2 µL
• Column Oven Programs: Initial 50 °C, 20 °C/min to 120 °C, 5 °C/min to 280–300 °C (10–15 min hold)

Methodology

The pesticides were dissolved in acetone at 0.5–2.0 mg/L. A 2 µL aliquot was injected onto different capillary columns. Full-scan chromatograms and selected zones were recorded in FTD and ECD modes. Relative retention times were calculated using EPN standard (30.000 min reference).

Main Results and Discussion

• DB-1 column provided baseline separation for many analytes but showed coelutions among isomers, requiring complementary detection modes.
• DB-5 improved separation of mid-range volatiles and offered distinct selectivity compared to DB-1.
• DB-1301 resolved late-eluting polar pesticides with minimal peak tailing.
• DB-17 delivered unique selectivity for nitrogen-containing and thermally labile compounds.
• Comprehensive relative retention time tables were established for all 124 pesticides on each column, enabling rapid library-based screening.

Benefits and Practical Applications

• Retention libraries accelerate initial screening and reduce false positives.
• Combining FTD and ECD enhances detectability across diverse chemical classes.
• Multi-column strategy allows method flexibility tailored to specific residue profiles.
• High-throughput capability supports routine monitoring in regulatory laboratories.

Future Trends and Potential Applications

• Integration with mass spectrometry for confirmatory analysis and quantification.
• Automation of retention time alignment tools to streamline screening workflows.
• Development of digital retention libraries for AI-driven phase prediction.
• Extension of multi-column approaches to other residue classes such as veterinary drugs.

Conclusion

Systematic evaluation of four capillary column phases and dual detection has established a robust framework for rapid screening of 124 pesticides. The generated retention time data serve as a valuable resource for analytical laboratories, facilitating compliance with food safety regulations.

Reference

Shimadzu Application Note C219-E007A: Analysis of 124 Pesticides With Capillary GC-FTD and GC-ECD.