Analysis of Captan, Folpet and Their Derivatives in Water by APCI-LCMS™-8060

Importance of the Topic

Captan and folpet, members of the phthalimide family, are extensively used fungicides in agriculture. Their transformation products, phthalimide and tetrahydrophthalimide, pose ecotoxic risks to aquatic ecosystems. Monitoring these substances in drinking and surface water is essential to ensure environmental safety and regulatory compliance.

Study Objectives and Overview

This study aimed to develop a rapid and sensitive method for quantifying captan, folpet, and their derivatives in water using direct injection and atmospheric pressure chemical ionization on a Shimadzu LCMS-8060 system. The goal was to achieve a low quantification limit with minimal sample preparation and a short analysis time.

Materials, Methods, and Instrumentation

The method was established using acidified water (0.1% acetic acid) as a calibration matrix. Tap water from Kyoto and surface water from the Tenjin River were spiked to assess matrix effects and repeatability. Key analytical conditions included:

• UHPLC column: Shim-pack Scepter C18 (1.9 μm, 30 × 2.0 mm) at 40 °C
• Mobile phases: water with 10 mM ammonium acetate and methanol, flow rate 200 μL/min
• Injection: 300 μL total (stacked 3 × 100 μL), run time 6 minutes
• Mass spectrometer: Shimadzu LCMS-8060 with APCI source; optimized MRM transitions via flow injection; source temperature 400 °C, heat block 300 °C; nebulizing and drying gas at 3 L/min each

Results and Discussion

Calibration curves were linear or quadratic over 9–900 pg/mL with correlation coefficients above 0.99. The limit of quantification was set at 27 pg/mL. Repeatability tests at 27, 45, and 63 pg/mL across distilled, tap, and river water showed RSD values below 12%. Accuracy ranged from 80% to 120% across all matrices, demonstrating reliable quantification without internal standards, although their use could further improve results.

Benefits and Practical Applications

The developed method offers:

• High sensitivity at the picogram-per-milliliter level
• Rapid analysis with a 6-minute run and no sample preparation
• Robust performance across different water matrices

This approach is well-suited for routine environmental monitoring, regulatory testing, and quality assurance in water analysis laboratories.

Future Trends and Potential Use

Future developments may include:

• Incorporation of isotopically labeled internal standards to correct matrix effects
• Expansion of the analyte panel to other pesticide residues and their metabolites
• Automation and high-throughput screening workflows
• Integration with advanced data analytics for real-time monitoring

Conclusion

A fast, sensitive, and reliable APCI-LCMS method on the Shimadzu LCMS-8060 has been established for quantifying captan, folpet, and their derivatives in water. The method achieves low detection limits, strong linearity, and acceptable precision and accuracy across various water types.

References

No explicit literature list was provided in the source document. Relevant regulatory and technical references include:

• European Commission Directive 2007/5/EC, Annex I to Directive 91/414/EEC
• Shimadzu LCMS-8060 and Nexera UHPLC product documentation