Bottled Water: Analyzing water purity for advanced chromatographic applications

Significance of the topic

High-purity water is a fundamental component in liquid chromatography (LC) and LC–mass spectrometry (LC–MS) workflows. Impurities such as organic compounds, bacteria, particles and dissolved gases can compromise sensitivity, generate background noise, cause ghost peaks and accelerate column and pump degradation. Ensuring water purity is therefore critical for accurate quantification in trace analysis, reliable calibration and reduced maintenance costs.

Objectives and overview of the study

This study compares the performance of commercially bottled HPLC-grade water with water produced by an ELGA PURELAB Chorus 1 Complete system. The aim is to assess consistency in total organic carbon (TOC) levels and the presence of trace organic contaminants (phthalates) over typical laboratory usage patterns.

Methodology and used instrumentation

• ELGA PURELAB Chorus 1 Complete system configured with a 30 L reservoir, dispensing 60 L/day over six months.
• Regular measurement of TOC approximately every two weeks to monitor organic load.
• HPLC analysis of phthalate esters in freshly opened bottled water and ultrapure water from the PURELAB system.

Main results and discussion

• The PURELAB system consistently delivered water with TOC levels below its specification throughout the six-month trial, demonstrating stable removal of organic impurities.
• HPLC traces revealed significantly higher phthalate concentrations in bottled water compared to ultrapure water, indicating potential sample contamination when using bottled sources.
• Observed impurities can compete for stationary-phase sites, inhibit analyte binding and lead to erroneous peak identification, particularly in automated data processing.

Benefits and practical applications of the method

• Reliable removal of organic compounds, bacteria and residual ions ensures accurate calibration, standards preparation and sample integrity.
• Minimised particle and biofilm formation in LC system components reduces maintenance frequency and overall running costs.
• Enhanced confidence in trace-level analyses supports applications in forensic science, clinical diagnostics, environmental monitoring and QA/QC workflows.

Future trends and opportunities

Innovations in water purification are focusing on compact, modular dispensers and integrated digital monitoring platforms. Remote performance tracking (e.g., ELGA’s Hubgrade) and real-time quality assessment will further streamline laboratory operations, support predictive maintenance and ensure uninterrupted analytical workflows.

Conclusion

The ELGA PURELAB Chorus range offers robust multi-stage purification to deliver ultrapure water that outperforms bottled alternatives in TOC control and trace contaminant removal. By preventing sample contamination and reducing system fouling, this approach underpins high-sensitivity LC and LC–MS analyses while optimising laboratory efficiency and costs.

References

• ELGA LabWater, “Bottled Water: Analyzing Water Purity for Advanced Chromatographic Applications,” VWS (UK) Ltd white paper, 2012.