Determination of 33 pesticide residues in Ginseng using gas chromatography-triple quadrupole mass spectrometry

Significance of the Topic

Monitoring pesticide residues in herbal products such as ginseng is essential for ensuring consumer safety and regulatory compliance. Ginseng is widely used in traditional medicine, and contamination with banned pesticide residues can pose health risks. A sensitive and reliable analytical method is necessary to detect trace levels of multiple pesticides in complex herbal matrices.

Objectives and Study Overview

This study aims to develop and validate a gas chromatography–triple quadrupole mass spectrometry (GC-MS/MS) method for simultaneous quantification of 33 banned pesticide residues in ginseng. The method follows the fifth method of general rule 2341 of the 2020 Chinese Pharmacopoeia.

Methods and Sample Preparation

• Sample extraction: 3 g ginseng powder soaked in 1% acetic acid, extracted with acetonitrile.
• Clean-up: QuEChERS style salt mixture (MgSO₄/NaOAc), followed by solid-phase dispersion and filtration.
• Internal standard: triphenyl phosphate added before analysis.
• Calibration: matrix-matched standards at 2–40 ng/mL; prohibited range 2–5 ng/mL; six replicate injections.
• Validation: linearity (R² > 0.995), recovery (60–110%), precision (RSD < 5%).

Instrumentation Used

• Instrument: Shimadzu GCMS-TQ8050 NX triple quadrupole GC-MS.
• Column: SH-Rxi-17Sil MS (30 m × 0.25 mm × 0.25 μm).
• Oven program: 60 °C (1 min) → 160 °C at 10 °C/min → 230 °C at 2 °C/min → 300 °C at 15 °C/min (6 min).
• Carrier gas: helium; collision gas: argon; ionization: EI; interface and source at 250 °C.
• Detection: MRM transitions optimized for each pesticide.

Main Results and Discussion

• Retention times were accurately predicted using n-alkane standards.
• Representative MRM chromatograms demonstrated clear separation and sensitivity.
• Calibration curves showed excellent linearity (R² > 0.995).
• Recovery tests at spiking levels of 0.01–0.025 mg/kg yielded recoveries between 60% and 110%.
• Method repeatability was confirmed with RSD values below 5%.
• All analytical criteria met the requirements of the 2020 Chinese Pharmacopoeia.

Benefits and Practical Applications

• High sensitivity and throughput enable routine screening of multiple residues.
• Applicable in quality control laboratories for herbal medicine analysis.
• Supports regulatory monitoring and ensures compliance with pharmacopoeial limits.

Future Trends and Opportunities

• Extension to other herbal matrices and pesticide classes.
• Integration with high-resolution mass spectrometry for non-target screening.
• Automation of sample preparation and data processing.
• Real-time monitoring and portable GC-MS applications.
• Data analytics and machine learning for pattern recognition in complex samples.

Conclusion

The developed GC-MS/MS method provides a robust, sensitive and reproducible tool for simultaneous determination of 33 banned pesticide residues in ginseng. It fully complies with the 2020 Chinese Pharmacopoeia requirements and is suitable for routine quality control of herbal medicines.

References

1. Chinese Pharmacopoeia Commission. General rule 2341: Determination of Pesticide Residues in Chinese Herbal Medicines (2020 Edition).
2. Bao X, Gou Y, Fan J, Huang T. Determination of 33 pesticide residues in Ginseng using GC-MS/MS. Shimadzu Application Note.