Analysis of Pesticides in Food by GC/MS/MS using the Ultra Inert Liners with Wool

Importance of the topic

Monitoring pesticide residues in food matrices is essential to ensure consumer safety and regulatory compliance. Complex sample matrices such as fruits and vegetables contain high boiling impurities and reactive analytes that challenge analytical systems. Enhancing inlet liner inertness and protection of the chromatographic path increases accuracy and instrument uptime.

Aims and overview of the study

This study evaluates the performance of Ultra Inert deactivated splitless liners packed with glass wool for multiresidue pesticide analysis in food extracts using GC MS MS. A set of 33 diverse and active pesticides was analyzed in QuEChERS prepared fruit and vegetable matrices. Comparative tests with conventional Siltek liners were conducted to assess chromatography sensitivity reproducibility and system protection.

Methodology and instrumentation

The QuEChERS AOAC extraction method was applied to five produce matrices. An Agilent 7890A GC coupled to a 7000 series triple quadrupole MS operated in MRM mode provided selective detection. Backflush enabled rapid removal of high boiling matrix components. Calibration standards in matrix were prepared from 5 to 500 ng per mL. Performance metrics included LOQ linearity injection repeatability liner to liner reproducibility and long term stability.

Main results and discussion

• High sensitivity was achieved with limits of quantitation at 5 ng per mL below most regulatory limits
• Calibration curves for 18 challenging pesticides displayed excellent linearity with r2 greater than 0.99 and RSD below 13 percent
• Liner to liner reproducibility across seven Ultra Inert liners yielded RSD values below 16 percent for active compounds
• Repeatability over 100 injections of neat standards remained below 12 percent RSD. Matrix injections showed some decrease in response for highly active analytes but maintained acceptable performance
• Compared to Siltek cyclosplitter and non wool liners Ultra Inert liners with wool provided superior inertness protection of the column and MS source and extended column life by over twofold

Benefits and practical applications

The enhanced inertness of glass wool liners prevents analyte degradation and adsorption leading to sharper peaks for polar and labile pesticides. Backflush capability reduces maintenance and analysis time. Laboratories performing routine multiresidue screening in food benefit from improved throughput lower downtime and consistent quantitative results.

Future trends and possibilities

Further advancements may integrate automated cleaning protocols and advanced deactivation chemistries. Expanding the approach to other challenging analyte classes such as pharmaceuticals and environmental toxins could enhance system robustness. Developments in MS detector technology combined with inert flow path components will continue to lower quantitation limits and improve data reliability.

Conclusion

Ultra Inert deactivated liners packed with glass wool demonstrate significant improvements for GC MS MS pesticide analysis in food. This approach delivers high sensitivity reliable reproducibility and extended instrument lifetime making it a valuable tool for high throughput laboratories focused on food safety.

Instrument used

• Agilent 7890A GC
• Agilent 7693 Autosampler
• Agilent 7000 Triple Quadrupole MS
• HP 5MS ultra inert 15 m x 0.25 mm x 0.25 µm column
• Purged Ultimate Union capillary flow device

References

1. Anastassiades M and Lehotay SJ Fast and easy multiresidue method employing acetonitrile extraction dispersive solid phase extraction for pesticide residues in produce J AOAC Int 2003 86 412 431
2. Szelewski MJ and Quimby B New tools for rapid pesticide analysis in high matrix samples Agilent Technol publication 5989 1716EN
3. Meng CK Improving productivity and extending column life with backflush Agilent Technol publication 5989 6018EN
4. Wylie PL and Meng CK Method for trace analysis of 175 pesticides using Agilent triple quadrupole GC MS MS Agilent Technol publication 5990 3578EN
5. Zhao L Schultz D and Stevens J Analysis of pesticide residues in apples using Agilent SampliQ QuEChERS AOAC kit by LC MS MS Agilent Technol publication 5990 3937EN
6. Giarrocco V and Quimby B Retention time locking concepts and applications Agilent Technol publication 5966 2469EN
7. Zhao L Broske AD and Mao D Evaluation of the Agilent Ultra Inert deactivation for active compounds by GC Agilent Technol publication 5990 7380EN