Mass Spectrometry Applications for Environmental Analysis

Význam tématu

Modern environmental monitoring demands rapid, sensitive and high‐throughput methods to detect trace levels of pesticides and herbicides in water. Traditional sample pre‐treatment with offline solid‐phase extraction (SPE) is time‐ and solvent‐consuming. Coupling direct ionization techniques or automated on‐line SPE to high‐resolution and tandem mass spectrometry enables faster response times, minimal manual handling and detection limits in the ng/L or sub‐ng/L range.

Cíle a přehled studie / článku

Multiple Thermo Fisher Scientific application notes illustrate advanced workflows for environmental analysis:

• Direct Analysis in Real Time (DART) ionization with Orbitrap high‐resolution accurate‐mass (HRAM) MS for rapid pesticide screening in water.
• Accela HPLC coupled to Exactive Orbitrap and EQuan™ on‐line SPE for targeted and non‐targeted pesticide screening.
• Fast‐HPLC large‐volume injection on TSQ Quantum Access for sub‐ppt targeted herbicide quantitation.
• TraceFinder™ and ExactFinder™ software platforms for streamlined data processing, quantitation and non‐targeted workflows.
• EPA Method 549.2–compliant LC‐MS/MS and on‐line SPE for triazines and for paraquat/diquat at femtogram levels using UV detection.

Použitá metodika a instrumentace

• DART‐SVP source with SVP controller coupled to Exactive Orbitrap HRAM MS for direct‐spray ionization (300 °C helium, m/z 100–500 scan).
• Thermo Scientific Exactive Orbitrap and Accela UHPLC: on‐line EQuan SPE system using Hypersil GOLD trap and analytical columns; large‐volume (1–20 mL) injections; full‐scan HRAM at 50 000 FWHM.
• TSQ Quantum Access MAX MS/MS with heated ESI; Accela or Surveyor LC pumps; trap‐and‐backflush configuration for automated large‐volume injection (5–20 mL).
• TraceFinder and ExactFinder software for acquisition control, automated targeted screening, calibration, non‐targeted elemental composition assignment and reporting.
• HPLC‐UV method (EPA 549.2 style) on Dionex UltiMate 3000 RSLC with Acclaim Trinity P1 guard and Trinity Q1 analytical columns; 100 mM ammonium acetate/ACN gradients; UV detection at 260/310 nm.

Hlavní výsledky a diskuse

• DART‐Orbitrap HRAM enabled identification of 23 pesticides in water at ng/mL levels with <1 ppm mass accuracy and detection of isotopic patterns for halogenated analytes.
• On‐line EQuan SPE‐Orbitrap workflows delivered linear response (0.02–0.6 µg/L), R²>0.99, and LODs down to tens of pg/L for 20 targeted herbicides, while non‐targeted screening revealed additional contaminants.
• Fast‐HPLC TSQ Quantum Access permitted sub‐ppt quantitation of 11 pesticides in 6 min runs, with R²>0.99 and MDLs well below regulatory limits.
• TraceFinder and ExactFinder streamlined method set‐up, batch acquisition and automated flagging of out‐of‐criteria results, reducing data review time.
• EPA‐compliant LC‐MS/MS triazine method achieved linearity from 0.25–5 ppb and MDLs of 0.09–0.10 µg/L.
• On‐line SPE‐UV method for paraquat/diquat attained MDLs of 0.09–0.10 µg/L and recoveries of 104–108% in tap and pond water, with <0.7 min peak widths.

Přínosy a praktické využití metody

• Dramatic reduction of analysis time: from hours or days (offline SPE) to minutes per sample.
• Lower solvent consumption and minimized manual intervention via automated on‐line SPE.
• High‐confidence identification through HRAM full‐scan spectra and MS/MS confirmation.
• Sub‐ppt sensitivity addressing stringent drinking water regulations (EPA, EU).
• Integrated software solutions for unified qualitative and quantitative workflows.

Budoucí trendy a možnosti využití

• Expansion of high‐resolution direct ionization (e.g., DART) combined with real‐time screening for emergency response scenarios.
• Increasing use of on‐line SPE and micro‐extraction devices to handle diverse sample matrices (soil‐water, food extracts).
• Integration of machine learning in software platforms for non‐targeted contaminant discovery and pattern recognition.
• Coupling of ambient ionization with portable MS systems for field‐deployable environmental monitoring.
• Development of multi‐residue methods incorporating new analyte classes (pharmaceuticals, personal care products) in comprehensive screening.

Závěr

Advanced coupling of direct ionization or automated on‐line SPE to high‐resolution and triple quadrupole MS platforms, together with dedicated data processing software, enables rapid, sensitive and robust determination of a broad range of pesticides and herbicides in water. These approaches offer high sample throughput, minimal sample preparation and compliance with stringent regulatory requirements, supporting both targeted and non‐targeted environmental analyses.

Reference

1. Cody RB et al. Anal. Chem. 2005, 77, 2297–2302.
2. Beck JR et al. Thermo Fisher Scientific Application Note 51878, 2010.
3. US EPA Method 549.2: Determination of paraquat and diquat in drinking water.
4. Rafferty JL et al. J. Chromatogr. A 2011, 1218, 2203–2213.
5. Beck JR, Yang C. Thermo Fisher Scientific Application Note AN63413, 2016.
6. Thermo Fisher Scientific. Acclaim Trinity Columns Technical Note, 2014.