AGILENT WATER ANALYSIS SOLUTIONS - Application Notebook

Significance of the topic

Environmental monitoring of water and wastewater for contaminants such as PAHs, PBDEs, organophosphate pesticides, and trace elements is crucial due to their toxicity, widespread occurrence, and stringent regulatory limits set by agencies like the U.S. EPA and the EU. Fast, sensitive, and reliable analytical methods help ensure compliance, protect public health, and support environmental research.

Objectives and overview of studies

• Develop and validate a rapid HPLC method for 24 PAHs in drinking water using automated SPE and dual FLD/DAD detection.
• Implement and enhance EPA Method 538 for 11 organic contaminants in drinking water via direct aqueous injection UHPLC-MS/MS.
• Establish a single-step extraction GC/MS/MS method for simultaneous analysis of PAHs and PBDEs in wastewater effluents.
• Apply U.S. EPA 200.7 guidelines for trace element analysis in water using next-generation ICP-OES sample introduction technology.

Methodology and instrumentation

• PAHs in Drinking Water: Automated SPE (Bond Elut Plexa) on 800 mL samples with 5% isopropanol; HPLC on Agilent Pursuit PAH 3 column; FLD with time-programmed excitation/emission and DAD at 254 nm for nonfluorescent compounds.
• EPA Method 538: Direct injection of 40 mL filtered water with deuterated internal standards; UHPLC on ZORBAX Eclipse Plus C18 column; Agilent 6460 triple quadrupole MS/MS with Jet Stream; two MRM transitions per analyte.
• Wastewater PAHs/PBDEs: Liquid–liquid extraction into hexane via overnight bottle rolling; analysis on Agilent 7890A GC with multimode inlet solvent vent; detection on 7000B triple quadrupole GC/MS/MS in EI-MRM mode.
• Trace Elements (EPA 200.7): Agilent 720 Series axial ICP-OES with SeaSpray nebulizer, glass cyclonic chamber, and high-speed Agilent SVS 2 sample introduction to decouple uptake and measurement for constant plasma load.

Main results and discussion

• PAHs in Drinking Water: Separation of 24 PAHs in 28 min; LOQs from 0.01 to 2.5 ng/L; recoveries 45–95%; linearity R² > 0.99; robust automation.
• EPA 538 Pesticides: UHPLC run time of 10 min; LODs 1–500 ng/L; linearity R² ≥ 0.9999; two transitions per analyte meet EU confirmation ratios; direct injection eliminates SPE.
• Wastewater PAHs/PBDEs: Resolution of 8 PAHs and 6 PBDEs in < 20 min; LOQs < 3 ng/L; recoveries and precision within CIP AQC limits; long-term stability < 2% over 6 h.
• Trace Elements: Sample-to-sample cycle reduced from ~210 s to 68 s; MDLs well below EPA 200.7 requirements; IPC drift < 2% over 6 h; accurate analysis of NIST SRMs and certified wastewater reference materials.

Benefits and practical applications

• Increased throughput lowers analysis time and operating costs in environmental laboratories.
• Automated and direct-injection workflows minimize sample handling, reducing potential errors and contamination.
• Advanced detection technologies (triple quadrupole MS/MS, simultaneous CCD ICP-OES) deliver high sensitivity, selectivity, and data quality.
• Compliance with U.S. EPA and EU guidelines ensures regulatory acceptance and reliable monitoring results.

Future trends and opportunities

• Integration of high-speed sample introduction and UHPLC/UHPSFC for even faster turnaround times.
• Expansion of multi-residue protocols to cover emerging contaminants (PFAS, pharmaceuticals, microplastics).
• Automation of end-to-end sample preparation, data acquisition, and reporting for 24/7 laboratory operation.
• Application of high-resolution MS and advanced data analytics for non-target screening and suspect compound identification in complex matrices.

Conclusion

By combining modern sample preparation techniques, high-performance chromatographic separations, and state-of-the-art detection platforms, these methods achieve rapid, sensitive, and reproducible quantitation of a wide range of water contaminants, while meeting or exceeding regulatory requirements and supporting effective environmental management.

References

• U.S. EPA Method 538: Determination of Selected Organic Contaminants in Drinking Water by LC-MS/MS.
• U.S. EPA Method 200.7: Inductively Coupled Plasma–Atomic Emission Spectrometry.
• UKWIR Chemical Investigations Programme for Wastewater Effluents.
• Agilent application notes and technical briefs on SPE, ICP-OES, GC/MS/MS, and LC/MS/MS technologies.