Quantitative Analysis of Pyrethroids in Soil and Sediment Using the Shimadzu LCMS-8050 Triple Quadrupole Mass Spectrometer

Importance of the Topic

Pyrethroid pesticides are extensively employed in agriculture and domestic pest control. Their persistence in soil and sediment poses ecological risks due to strong adsorption and low water solubility. Although pyrethroids exhibit low toxicity to humans, they are highly toxic to aquatic organisms and insects. Accurate and sensitive monitoring of these residues is essential for environmental safety assessments and regulatory compliance.

Objectives and Study Overview

This study demonstrates a rapid, sensitive method for simultaneous quantification of 14 pyrethroid compounds in soil and sediment. Using the Shimadzu LCMS-8050 triple quadrupole mass spectrometer with electrospray ionization, the work aims to establish robust MRM transitions, generate calibration curves, and validate a streamlined QuEChERS sample-preparation protocol tailored for environmental matrices.

Methodology and Instrumentation Used

• Instrumentation:
  
  • Shimadzu Nexera X2 UHPLC system
  • Shimadzu LCMS-8050 triple quadrupole mass spectrometer with ESI in positive/negative mode
  • Phenomenex Kinetex 2.6 µm PFP 100Å column (100 mm × 2.1 mm)
• Chromatographic Conditions:
  
  • Mobile Phase A: 5 mM ammonium acetate in water
  • Mobile Phase B: Methanol
  • Gradient: 40 %B (0 min) to 100 %B (10–12 min), then return to 40 %B by 15 min
  • Flow Rate: 0.2 mL/min; Oven: 40 °C; Injection: 1 µL
• Mass Spectrometry:
  
  • ESI probe voltage: +4.0 kV / −3.0 kV
  • Drying gas: 15 L/min; Nebulizing gas: 3 L/min; Heater gas: 15 L/min
  • Interface/DL temperature: 100 °C; Block heater: 400 °C
• MRM Optimization and Calibration:
  
  • 14 pyrethroids monitored with optimized precursor/product m/z transitions
  • Calibration ranges: 0.01 to 500 µg/L; correlation coefficients (r²) ≥ 0.997
• Sample Preparation (QuEChERS):
  
  • Extraction: 5 g soil or 10 g sediment with 10 mL acetonitrile, water, and salt blend (MgSO₄, NaCl, trisodium citrate, hydrogencitrate)
  • dSPE Cleanup: 6 mL extract with MgSO₄, PSA, GCB; centrifugation and filtration
  • Total prep time: ~15 min per sample

Main Results and Discussion

All target compounds achieved clear chromatographic separation within a 12-minute run. Calibration curves exhibited excellent linearity (r² > 0.997). Limits of quantification ranged from 0.01 to 0.5 µg/L depending on the analyte. Recovery experiments using spiked soil and sediment yielded 70–120% efficiency, confirming method accuracy and reproducibility. MRM chromatograms demonstrated low-background noise and sharp peak shapes at low ppb levels.

Benefits and Practical Applications

• High sensitivity and specificity for multi-residue pyrethroid analysis
• Rapid throughput with a total analysis time under 15 minutes per sample
• Minimal solvent use and simplified cleanup via QuEChERS, reducing labor and cost
• Suitable for routine environmental monitoring and regulatory compliance testing

Future Trends and Potential Applications

Advances may include integration of automated QuEChERS platforms, expansion to other pesticide classes, and coupling with high-resolution mass spectrometry for non-targeted screening. Green extraction solvents and microextraction techniques could further reduce environmental footprint while maintaining analytical performance.

Conclusion

The presented LC-MS/MS method provides a fast, reliable, and sensitive solution for quantifying pyrethroid residues in soil and sediment. Its combination of streamlined sample preparation and robust chromatographic performance supports comprehensive environmental risk assessments and quality-control programs.

References

• Shimadzu Corporation. Quantitative Analysis of Pyrethroids in Soil and Sediment Using the Shimadzu LCMS-8050 Triple Quadrupole Mass Spectrometer. Application News No. C100, First Edition January 2015.