Drinking water quality by EPA 300.1

Significance of the Topic

The assurance of safe drinking water is fundamental for public health and regulated by agencies such as the US EPA under Method 300.1. Combining the analysis of major inorganic anions and disinfection byproducts (DBPs) in a single run enhances laboratory efficiency and safeguards regulatory compliance.

Objectives and Study Overview

This study aimed to integrate EPA Method 300.1 parts A and B into one ion chromatography sequence. It evaluated the simultaneous determination of high-level anions (chloride, nitrate, sulfate) and trace DBPs (chlorite, chlorate, bromate) alongside other anions and a surrogate marker (dichloroacetate).

Methodology and Instrumentation

Samples and standards were filtered inline and injected at 20 µL into an ion chromatograph with sequential suppression. Separation was achieved isocratically on a Metrosep A Supp 7-250/4.0 column with 3.6 mmol/L sodium carbonate at 45 °C. Detection employed conductivity suppression, and data analysis was performed with MagIC Net software.

Used Instrumentation

• 940 Professional IC Vario ONE with sequential suppression and peristaltic pump
• IC Conductivity Detector
• Metrosep A Supp 7-250/4.0 column
• 858 Professional Sample Processor with inline ultrafiltration
• MagIC Net 4.0 Compact software

Main Results and Discussion

Tap water samples contained milligram-per-liter levels of chloride (13 mg/L), sulfate (4 mg/L), and nitrate (8 mg/L). Trace analytes bromide and fluoride were detected below 0.06 mg/L, while DBPs and nitrite were below detection limits. Baseline separation with resolution >1.5 and detector linearity up to 15,000 µS/cm enabled a five-order-of-magnitude dynamic range. RSDs were below 2.5% for most analytes, and spike recoveries ranged from 82 to 120%, meeting EPA criteria.

Benefits and Practical Applications

• Single-run analysis reduces sample throughput time and resource consumption
• High sensitivity and resolution allow simultaneous quantification across a broad concentration range
• Compliance with US EPA Method 300.1 and EN ISO 10304 parts 1 and 4

Future Trends and Applications

Further integration of inline sample preparation and automated dilution can streamline workflows. Alternative detectors such as UV/VIS or amperometric sensors may improve sensitivity for specific analytes. Coupling with mass spectrometry and digital data management will support advanced water quality monitoring and regulatory reporting.

Conclusion

The combined EPA 300.1 method using a Metrosep A Supp 7 column with suppressed conductivity detection delivers robust, high-throughput analysis of major anions and DBPs in drinking water. This approach meets stringent regulatory requirements while enhancing laboratory efficiency.

Reference

• World Health Organization. Guidelines for Drinking-Water Quality, 2006.
• Boorman G. A. Environ. Health Perspect. 1999;107(suppl 1):207–217.
• Evans S.; Campbell C.; Naidenko O. V. Int. J. Environ. Res. Public Health. 2020;17(6):2149.
• IARC Monographs Volume 84. 2004.
• Jackson P. E. Ion Chromatography in Environmental Analysis. 2000.
• EPA National Primary Drinking Water Regulations. Fed. Regist. 1998;63(241):69389–69476.
• Singer P. C. J. Environ. Eng. 1994;120(4):727–744.
• US EPA Method 300.1. 2000.