Dual Confirmation of EPA Method 8330 explosives using DUIS-equipped Single Quadrupole LCMS-2050 and PDA for Tandem Detection

Význam tématu

Environmental contamination by military and industrial explosives threatens soil, water, and sediment quality. Reliable detection of these analytes and their degradants is essential for regulatory compliance and public health protection. Combining chromatographic separation with complementary detectors enhances confidence in results while improving laboratory throughput.

Cíle a přehled studie

This work presents a single-injection approach for EPA Method 8330 explosive panels. By integrating ultra-high-performance liquid chromatography (UHPLC) on a C18 reversed-phase column with tandem photodiode array (PDA) and single-quadrupole mass spectrometry (MS), the method aims to detect and confirm a broad suite of nitro-explosive compounds and related degradants in aqueous matrices while meeting federal confirmation requirements.

Použitá metodika a instrumentace

UHPLC conditions

• System: Shimadzu Nexera UHPLC
• Column: Shim-pack Velox SP-C18 (2.7 µm, 2.1×100 mm), 30 °C
• Mobile phase: 5 mM ammonium acetate in water (A) and methanol (B), isocratic 75 % A : 25 % B, flow 0.4 mL/min
• Injection volume: 2 µL

Detection

• PDA: Shimadzu SPD-M40, compound-specific λmax settings for 17 analytes
• MS: Shimadzu LCMS-2050 with DUIS source in negative SIM mode
• Optimized interface voltages (–1 to –5 kV), desolvation at 450 °C, DL 200 °C, gas flows: nebulizing 2 L/min, drying 5 L/min, heating 7 L/min

Hlavní výsledky a diskuse

Tandem detection enabled quantitation of 17 target compounds by PDA with limits of quantitation down to 0.02 µg/mL and linear ranges up to 5 µg/mL. Single-quadrupole MS confirmed 13 compounds via SIM with signal-to-noise >10 at LOQ levels. Calibration curves exhibited excellent correlation (R2 > 0.99), accuracy within 70–130 %, and precision (%RSD area) mostly below 10 %. Interface voltage optimization identified the most responsive settings for each analyte, balancing sensitivity and thermal stability.

Přínosy a praktické využití metody

• Single-injection workflow reduces analysis time and resource consumption
• Simultaneous quantitation (PDA) and confirmation (MS) in one run ensures EPA 8330 compliance
• High sensitivity and reproducibility support trace-level monitoring in environmental and industrial laboratories

Budoucí trendy a možnosti využití

Future developments may include coupling with high-resolution MS for enhanced selectivity, expanding the method to solid and sediment matrices, and integrating automated sample preparation for high-throughput environmental monitoring and forensic applications.

Závěr

This study demonstrates a robust UHPLC-PDA–SQ-MS method for comprehensive detection and confirmation of explosive residues in water with a single injection. The approach streamlines EPA Method 8330 workflows while delivering reliable quantitative and confirmatory data.

Reference

Zerda-Pinto V., Hain E.R., Mendis L.T., Monti S., Olendorff S.A., Marfil-Vega R., Wiest L.A., Gilles C. Dual Confirmation of EPA Method 8330 explosives using DUIS-equipped Single Quadrupole LCMS-2050 and PDA for Tandem Detection. Shimadzu Scientific Instruments, Columbia, MD, 2023.