Bottled Water: Analyzing water purity for advanced chromatographic applications

Significance of the topic

High purity water is fundamental for liquid chromatography and LC-MS applications where detection limits reach parts per billion. Impurities such as organic compounds, dissolved gases, particles and bacteria can increase baseline noise, produce ghost peaks and damage column and pump components. Reliable purification prevents sample degradation, inaccurate calibration and elevated maintenance costs, ensuring reproducible, high-sensitivity separations.

Objectives and overview of the article

This white paper evaluates the performance of bottled HPLC-grade water versus water produced by the ELGA PURELAB Chorus purification system. Key aims include assessing total organic carbon stability over time and quantifying trace phthalate contamination. The study demonstrates how a dedicated purification platform can deliver consistently ultrapure water suitable for advanced chromatographic analyses.

Methodology and instrumentation

A PURELAB Chorus 1 Complete unit equipped with a 30-liter reservoir was supplied with tap water and programmed to dispense 60 liters per day over six months. Total organic carbon was measured biweekly to monitor system consistency. Bottled HPLC-grade water was freshly opened and analyzed in parallel. Phthalate levels were determined by HPLC with UV detection, comparing chromatograms of bottled water and ultrapure output from the PURELAB system. Key instrumentation

• PURELAB Chorus 1 Complete purification system
• TOC analyzer for biweekly measurements
• HPLC with UV absorbance detection for phthalate profiling

Main results and discussion

The PURELAB system consistently delivered water with TOC levels well below the specification threshold, demonstrating stable long-term removal of organics. In contrast, bottled water showed significantly higher and variable phthalate peaks in HPLC traces. Phthalate esters in bottled samples exceeded the trace levels recorded for ultrapure output, indicating potential contamination risks if used for eluent or sample preparation. Reliable quality monitoring in the PURELAB Chorus minimized unexpected background signals and protected analytical performance.

Benefits and practical applications of the method

Use of a dedicated purification system offers clear advantages for analytical laboratories

• Assured low background and ghost-peak elimination
• Improved calibration accuracy and reproducibility
• Reduced maintenance and extended life of LC columns and pumps
• Minimized risk of sample or standard contamination

Future trends and possibilities for use

Advances in purification media and real-time digital monitoring are set to further enhance water quality management. Integration with laboratory information systems and smart sensors can provide continuous performance feedback and predictive maintenance alerts. Emerging applications in bioanalysis, environmental testing and on-site field chromatography will benefit from compact, efficient purification devices. Sustainable consumable development and reduced water waste will also drive innovation in this field.

Conclusion

The ELGA PURELAB Chorus range provides a robust solution for generating ultrapure water essential to high-sensitivity LC and LC-MS workflows. By effectively removing organic compounds, bacteria and residual ions, the system ensures reliable calibration and contamination-free sample preparation. Consistent water quality reduces maintenance demands and supports reproducible analytical results across demanding chromatographic applications.

References

1. VWS UK Ltd Bottled Water Analyzing water purity for advanced chromatographic applications White paper 2012