Molecular structure of water reflecting ultrapure quality testing

Application Notes

The Importance of Ultrapure Water Testing for Accurate Results

Ensure accuracy in ultrapure water testing for drinking water by eliminating background interference in ion chromatography workflows.

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Application note on drinking water testing with ultrapure water by Ion Chromatography

Inorganic ions and disinfection by-products (DBPs) in drinking water are strictly regulated due to their detrimental effects on human health and organoleptic properties. Ion chromatography (IC) is the standard analytical method used to monitor these contaminants, requiring water of the highest purity for eluents, standards, blanks, and sample preparation. This application note demonstrates how ultrapure water freshly delivered by a Milli-Q® IQ 7000 water purification system effectively removes trace-level contaminants. Even when feed tap water contains large amounts of inorganic ions or DBPs, the system delivers water with undetectable levels of interference, ensuring accurate and reliable IC results.

Key Learning Points

Eliminate Background Interference: Learn how ultrapure water (18.2 MΩ·cm, TOC < 5 ppb) reduces nitrate (NO₃^-) levels up to 140,000-fold lower than WHO and EU regulatory limits, preventing baseline contamination.
Control Harmful DBPs: Discover how an EDI-based and ultrapure purification chain efficiently removes trace disinfection by-products—including bromate, chlorate, and chlorite—to concentrations well below regulatory limits.
Optimize Your IC Workflows: Gain practical guidelines for selecting and implementing high-purity water systems to prepare blanks, standards, and water-based eluents with confidence.

_{*The Life Science business of Merck, KGaA, Darmstadt, Germany operates as MilliporeSigma in the U.S. and Canada}

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Ensure Accuracy in Drinking Water Testing with Ultrapure WaterAchieve ultra-low detection limits and eliminate background interference in Ion Chromatography (IC) workflows using high-purity water solutions.AbstractInorganic ions and disinfection by-products (DBPs) in drinking water are strictly regulated due to their detrimental effects on human health and organoleptic properties. Ion chromatography (IC) is the standard analytical method used to monitor these contaminants, requiring water of the highest purity for eluents, standards, blanks, and sample preparation. This application note demonstrates how ultrapure water freshly delivered by a Milli-Q® IQ 7000 water purification system effectively removes trace-level contaminants. Even when feed tap water contains large amounts of inorganic ions or DBPs, the system delivers water with undetectable levels of interference, ensuring accurate and reliable IC results. Key Learning PointsEliminate Background Interference: Learn how ultrapure water (18.2 MΩ·cm, TOC < 5 ppb) reduces nitrate ($NO_3^-$) levels up to 140,000-fold lower than WHO and EU regulatory limits, preventing baseline contamination. Control Harmful DBPs: Discover how an EDI-based and ultrapure purification chain efficiently removes trace disinfection by-products—including bromate, chlorate, and chlorite—to concentrations well below regulatory limits. Optimize Your IC Workflows: Gain practical guidelines for selecting and implementing high-purity water systems to prepare blanks, standards, and water-based eluents with confidence. What’s Inside the Technical NoteRegulatory Benchmarks: Detailed comparison tables mapping tap water and ultrapure water ion concentrations against strict WHO, EPA, FDA, and EU drinking water limits. Chromatographic Evidence: Real-world IC chromatograms comparing anionic and cationic standard mixes against freshly dispensed ultrapure water. Methodology & Instrumentation: Comprehensive experimental conditions following EPA Method 300.1 and ISO norms for trace-level anion, cation, and DBP quantification.