Pesticides Analysis Using the Agilent 5977A Series GC/MSD

Importance of the Topic

The reliable detection of pesticide residues in food is critical for consumer safety and regulatory compliance. With global trade expanding and over 1,000 pesticides registered worldwide, sensitive, accurate, and reproducible analytical methods are essential to enforce maximum residue levels (MRLs) in diverse matrices.

Objectives and Study Overview

This application note evaluates the performance of the Agilent 5977A Series GC/MSD for quantifying 42 commonly used pesticides in China. Key goals include assessing linearity, reproducibility, and minimum detection limits (MDLs) in both solvent standards and spiked apple matrices to ensure compliance with Chinese MRL requirements.

Methodology and Used Instrumentation

Sample preparation employed a modified QuEChERS-like approach:

• Homogenization of 20 g apple with 40 mL acetonitrile and NaCl partitioning
• Centrifugation, solvent evaporation, and cleanup on a Bond Elut carbon/NH2 column
• Final extract in hexane (10 mL) used for 50 ng/mL matrix-matched standards

Instrumentation and conditions:

• Gas chromatograph: Agilent 7890B with splitless inlet, HP-5ms Ultra Inert column (30 m × 0.25 mm, 0.25 µm)
• Mass spectrometer: Agilent 5977A Series GC/MSD, electron ionization, SIM mode
• Carrier gas: Helium at 1 mL/min; oven program from 60 °C to 310 °C
• Source temperature: 250 °C; quadrupole: 150 °C; solvent delay: 3.5 min

Main Results and Discussion

Linearity:

• Calibration range: 20–200 ng/mL
• All 42 pesticides exhibited R2 ≥ 0.991

Reproducibility and MDLs in solvent:

• RSDs mostly around 5% (none >11%) across eight injections
• Calculated MDLs between 3 and 14.3 ppb, average ~6.7 ppb

Reproducibility and MDLs in apple matrix:

• RSDs generally lower than solvent results (often 2–4%)
• MDLs mostly ~3–7.5 ppb, all below Chinese MRLs (0.01–5 mg/kg depending on matrix)

Benefits and Practical Applications

This method delivers high sensitivity and accuracy for multi-residue pesticide screening in food. The combination of automated sample preparation and robust GC/MSD analysis ensures increased laboratory throughput, consistency, and confidence in meeting stringent regulatory limits.

Future Trends and Opportunities

Advances may include:

• Integration of high-resolution mass spectrometry for broader residue screening
• Further miniaturization and automation to reduce solvent consumption
• Development of universal workflows for emerging pesticide classes

Conclusion

The Agilent 5977A Series GC/MSD, coupled with automated sample prep, provides a reliable, reproducible, and sensitive solution for simultaneous analysis of 42 pesticides. The achieved MDLs and reproducibility exceed the requirements of Chinese regulation GB 2763-2012, supporting routine food safety monitoring.