Water Analysis

Significance of the Topic

The safety and purity of drinking water are critical public health concerns, especially in regions experiencing rapid industrial activity such as oil and gas development. Ensuring reliable detection of organic contaminants and gases in water supplies supports regulatory compliance, community confidence, and rapid response to potential pollution.

Objectives and Study Overview

This case study describes a partnership between Weld County Public Health Laboratory (Colorado, USA) and PerkinElmer aimed at expanding the laboratory’s water testing capabilities. Key goals included:

• Implementing EPA Method 524.2 for volatile organic compounds (VOCs) in water.
• Developing a headspace GC method for dissolved hydrocarbon gases (methane, ethane, ethylene, propane).
• Creating a mass spectrometry–based assay for haloacetic acids (HAA5) to streamline disinfection by-product analysis.

Used Instrumentation

• PerkinElmer Clarus GC/MS system with purge and trap sample introduction.
• Headspace sampler for volatiles and dissolved gases.
• Liquid autosampler for derivatized haloacetic acids.

Methodology

The collaboration proceeded in three phases:

1. Purge and trap GC/MS following EPA Method 524.2 to measure purgeable organics in water. Method validation included Method Detection Limit studies, precision and accuracy checks, and proficiency testing under state certification.
2. Adaptation of headspace GC for low-level hydrocarbon gases based on EPA RSK-175, enabling measurement of methane, ethane, ethylene, and propane in groundwater.
3. Development of a liquid-liquid extraction and derivatization protocol for haloacetic acids (HAA5), transitioning from traditional gas chromatography–ECD to GC/MS to improve selectivity and remove the need for dual columns.

Main Results and Discussion

Weld County successfully certified for Method 524.2 in 2012 and has since tested over 200 private wells for VOCs and hydrocarbon gases. No contamination linked to hydraulic fracturing was detected. The newly developed HAA5 method demonstrated robust identification of monochloroacetic, dichloroacetic, trichloroacetic, monobromoacetic, and dibromoacetic acids. Integrating all techniques on a single GC/MS platform reduced equipment costs and laboratory space requirements.

Benefits and Practical Applications of the Method

• Enhanced community trust by providing rapid in-house testing at half the turnaround time of outsourced analyses.
• Cost savings through consolidation of multiple analytical techniques on one instrument.
• Regulatory compliance and improved data quality via mass spectrometric confirmation.

Future Trends and Applications

Emerging priorities include expanding multi-residue screening for semi-volatile or emerging contaminants using high-resolution mass spectrometry, integrating automated data processing workflows, and applying similar consolidated approaches in other environmental matrices (soil, air). Collaborative models between public laboratories and industry suppliers can accelerate method development and technology transfer.

Conclusion

The Weld County–PerkinElmer collaboration illustrates how strategic partnerships and flexible instrumentation can expand a public health laboratory’s analytical portfolio. By unifying purge and trap, headspace, and liquid injection workflows on one GC/MS system, the laboratory achieved reliable, cost-effective water testing for VOCs, hydrocarbon gases, and haloacetic acids, thereby enhancing environmental surveillance and public confidence.

References

1. Weld County Department of Public Health and Environment. About the Health Department. Weld County Website.
2. EPA Method 524.2. Measurement of Purgeable Organic Compounds in Water Using Capillary Column GC/MS.
3. Kampbell DH, Vandegrift SA. Analysis of Dissolved Methane, Ethane, and Ethylene in Ground Water by a Standard Gas Chromatographic Technique. Journal of Chromatographic Science. 1998;36:253–256.
4. Marotta L. The Determination of Low Level Benzene, Toluene, Ethyl Benzene and Xylenes (BTEX) in Drinking Water by Headspace Trap GC/MS. PerkinElmer Application Note.
5. Marotta L, Yates D. Methane, Ethylene, and Ethane in Water by Headspace-Gas Chromatography (HS-GC) with Flame Ionization Detection (FID). PerkinElmer Application Note.
6. EPA Method 552.3. Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Extraction, Derivatization and Gas Chromatography Coupled with ECD.