Analysis of Semivolatile Organic Compounds in Drinking Water on the Agilent 8890 GC and 5977 GC/MSD with Extended Calibration Range

Significance of the Topic

The accurate detection of semivolatile organic compounds in drinking water is critical for public health and regulatory compliance. Gas chromatography with mass selective detection provides the sensitivity and selectivity required by EPA method 525 to monitor contaminants such as pesticides, polynuclear aromatic hydrocarbons, and other semivolatiles at trace levels.

Objectives and Study Overview

This application note evaluates an Agilent 8890 gas chromatograph coupled with a 5977 mass selective detector for analysis of over 100 semivolatile compounds in drinking water according to EPA method 525. The study aims to extend the calibration range to 0.02–15 ng/µL, verify chromatographic resolution and instrument suitability, and demonstrate sensitivity across a broad dynamic range.

Methodology and Instrumentation

Sample preparation employed three multicomponent standards diluted in ethyl acetate to generate ten calibration levels from 0.02 to 15.3 ng/µL. Internal standards and surrogates were added at a constant level of 5 ng/µL. Calibration was assessed by average response factor and weighted linear regression, dropping low levels if criteria were not met.

Instrumentation

• Gas chromatograph: Agilent 8890 GC
• Mass spectrometer: Agilent 5977 MSD with inert electron ionization source
• Column: Agilent DB-8270D Ultra Inert, 30 m × 0.25 mm × 0.25 µm
• Drawout plate: 9 mm diameter
• Autosampler: Agilent 7650A liquid sampler
• Carrier gas: helium at 1.2 mL/min constant flow
• Inlet temperature: 250 °C with pulsed splitless mode
• Transfer line: 270 °C; ion source: 320 °C; quadrupole: 200 °C

Instrument performance was validated using an IPC standard containing DFTPP, endrin, and 4,4’-DDT. Chromatographic resolution met EPA requirements for anthracene/phenanthrene and benz[a]anthracene/chrysene pairs.

Key Results and Discussion

• Baseline separation achieved for anthracene and phenanthrene; ≥25% resolution for benz[a]anthracene/chrysene.
• Extended calibration from 0.02 to 15 ng/µL successfully covered 99 of 102 analytes; three compounds required weighted regression.
• Average relative standard deviation of response factors was 12.7% for the extended range versus ~9% for narrower ranges, reflecting the wider dynamic range.
• Surrogate compounds held at 5 ng/µL exhibited stable response factors with RSD below 5%.

Benefits and Practical Applications of the Method

The Agilent 8890 GC and 5977 MSD deliver high sensitivity and extended linear range for semivolatile analysis, reducing the need for sample reanalysis when concentrations fall outside standard calibration intervals. The 9 mm drawout plate enhances dynamic range and reproducibility for routine drinking water testing.

Future Trends and Potential Applications

Ongoing improvements in inlet design and column chemistry may further increase dynamic range and robustness. Automation of sample preparation and data processing will streamline high-throughput environmental testing. Regulatory drives toward lower reporting limits will require continued enhancements in detector sensitivity and calibration strategies.

Conclusion

The combined Agilent 8890 GC and 5977 MSD system meets EPA method 525 requirements and enables an extended calibration range of 0.02–15 ng/µL for semivolatile organic compounds in drinking water. The platform offers reliable chromatographic resolution, sensitivity, and operational efficiency for regulatory and research laboratories.

References

• Padilla-Sánchez JA, Plaza-Bolaños P, Frenich AG. Applications and Strategies based on Gas Chromatograph–Low-Resolution Mass Spectrometry for Environmental Samples. In Ferrer I, Thurman E, editors. Advanced Techniques in GC-MS for Environmental Chemistry. Elsevier; 2013. p. 181-202.
• US EPA. Method 525.2: Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary GC/MS. EPA; 1995.
• US EPA. Method 525.3: Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary GC/MS. EPA; 2012.
• Arizona Department of Environmental Quality. Chapter 11 Water Quality Standard. ADQ; 2016.
• Giardina M. Analysis of Semivolatile Organic Compounds in Drinking Water on the Agilent Intuvo and 5977 with Extended Calibration Range. Agilent Application Note 5994-0013EN; 2018.
• Agilent Technologies. Endrin and DDT Stability Study for Drinking Water Methods with an Agilent 8890 GC/5977B GC/MSD Combined System. Application Note 5994-0444EN; 2019.