Paraquat and Diquat Using Acclaim Trinity Q1 with UV Detection

Význam tématu

Cetylpyridinium, paraquat and diquat are widely used cationic agents with applications ranging from oral care formulations to herbicides. Due to their toxicity and regulatory limits in water and food products, reliable analytical methods are essential to ensure safety and compliance. The presented method addresses challenges of sensitivity, selectivity and matrix interference in complex samples such as mouthwash.

Cíle a přehled studie / článku

The primary objective was to develop and validate a robust chromatographic method for simultaneous determination of cetylpyridinium, paraquat and diquat in mouthwash. Thermo Scientific Acclaim Surfactant Plus and Acclaim Trinity Q1 columns were evaluated in combination with UV and suppressed conductivity detection to achieve fast separation, high resolution and broad dynamic range.

Použitá metodika a instrumentace

• Columns: Acclaim Surfactant Plus Q1, 3.0 × 150 mm, 3 μm particle size
  
• Instrument: Thermo Scientific Dionex ICS-3000 IC system
  
• Detectors: Diode array UV (257 nm, 310 nm) and suppressed conductivity (CSRS™ 300 suppressor)
  
• Mobile phases:
  
  • A: Acetonitrile
  • B: 100 mM formic acid in water (for LC/MS) or 100 mM monobasic/dibasic ammonium phosphate, pH 5.8 (for UV)
  • C: Water
• Gradient: Initial high organic content for retention control, followed by 100% aqueous buffer wash to remove calcium/magnesium interferences
  
• Flow rate: 0.50 mL/min; Column temperature: 25 °C; Injection volume: 5 µL
  

Hlavní výsledky a diskuse

• Retention times: Paraquat and diquat elute within 6 minutes with baseline separation; cetylpyridinium detected with suppressed conductivity after buffer wash step.
• Peak shape: Gaussian and symmetric peaks achieved by surfactant-compatible phase chemistry.
• Sensitivity: Low-µg/L detection limits; broad linear dynamic range up to 1 000 µg/L for herbicides.
• Matrix effects: Effective removal of divalent cations by high-strength buffer wash preserved column performance over multiple injections.

Přínosy a praktické využití metody

• Enables routine quality control of mouthwash and oral care products for regulatory compliance.
• Applicable to environmental monitoring of herbicide residues in water samples.
• Versatile detection modes support both UV and MS-based workflows.
• Short analysis time increases sample throughput in QA/QC laboratories.

Budoucí trendy a možnosti využití

Method enhancements may include coupling to high-resolution mass spectrometry for improved selectivity, miniaturized or UHPLC formats for faster analysis, and automated on-line sample cleanup to further reduce matrix interferences. Expanding the scope to additional cationic surfactants or emerging contaminants will broaden the method’s applicability.

Závěr

The optimized Acclaim Surfactant Plus/Trinity Q1 method delivers fast, reliable separation and quantification of cetylpyridinium, paraquat and diquat in complex matrices. Its robust performance, low detection limits and flexible detection options make it a valuable tool for pharmaceutical, environmental and industrial laboratories.

Použitá instrumentace

• Thermo Scientific Dionex ICS-3000 Ion Chromatography system
• Diode array detector (257 nm, 310 nm)
• Conductivity detector with CSRS™ 300 suppressor