Analysis of Multiresidue Pesticides Present in Ayurvedic Churna by GC-MS/MS

Importance of the Topic

Ayurvedic herbal formulations such as churna can accumulate pesticide residues from raw plant materials. Ensuring their safety and quality requires sensitive and selective analytical methods capable of detecting multiple residues in complex matrices. GC-MS/MS provides the necessary specificity and sensitivity for routine screening and regulatory compliance.

Study Objectives and Overview

The study aimed to develop and validate a robust multi-residue analysis method for over 100 pesticide compounds in Ayurvedic churna. Key goals included overcoming matrix interferences, achieving reliable quantitation, and demonstrating method performance on real samples from the market.

Methodology and Instrumentation

The analytical workflow combined a two-step sample preparation and optimized GC-MS/MS acquisition:

• Sample Preparation: Liquid-liquid extraction followed by dispersive solid-phase extraction (dSPE) cleanup to reduce co-extractives.
• Chromatography and Detection: Thermo Scientific TSQ 8000 triple quadrupole GC-MS/MS operated in timed SRM mode with electron impact ionization. Key settings included an ion source temperature of 230 °C, interface temperature of 285 °C, and a 3 µL injection volume via Triplus RSH autosampler.
• Data Processing: Thermo Scientific TraceFinder software with one SRM transition for quantitation and a second for confirmation.

Main Results and Discussion

The optimized method demonstrated:

• High linearity with correlation coefficients (r²) above 0.99 for most pesticides.
• Satisfactory recoveries and low matrix effects across diverse pesticide chemistries.
• Limits of quantitation suitable for regulatory thresholds.
• Successful application to commercial churna samples, revealing detectable residues in some cases.

The use of timed SRM transitions ensured selectivity in the presence of complex herbal matrices, and the dSPE cleanup minimized ion suppression.

Benefits and Practical Applications

This GC-MS/MS method offers:

• High-throughput screening of multiple residues in a single run.
• Robust quantitation for quality control in herbal product manufacturing.
• Compliance with international safety standards.
• Adaptability to other botanical matrices requiring similar analysis.

Future Trends and Potential Applications

Advancements in analytical chemistry may include:

• Expansion of compound libraries to cover emerging pesticide classes.
• Integration of automated sample preparation for greater throughput.
• Use of high-resolution mass spectrometry for non-targeted screening.
• Enhanced data analytics and machine learning for pattern recognition in complex matrices.

Conclusion

The presented GC-MS/MS approach delivers a reliable, sensitive, and selective platform for multi-residue pesticide analysis in Ayurvedic churna. Its validated performance and practical workflow support routine quality control and regulatory adherence in herbal pharmaceutical applications.