A Rapid LCMS Method for Evaluation of EPA 1694 and 6810 Contaminants in Drinking Water

Significance of the Topic

Monitoring contaminants of emerging concern (CECs) such as endocrine disruptors, pharmaceuticals and personal care products in drinking water is essential to protect public health and aquatic ecosystems at trace levels (pg/mL). Early and accurate detection supports regulatory compliance and informed treatment decisions.

Objectives and Overview

This study introduces a rapid five-minute ultra-fast LC-MS/MS workflow for simultaneous analysis of 24 EPA 1694 and 6810 target compounds. It evaluates method speed, sensitivity and suitability for direct drinking water analysis with minimal preparation.

Methodology and Instrumentation Used

• Sample Preparation: Direct injection of 1 µL tap water without cleanup.
• Chromatography: Raptor Biphenyl column (100 × 2.1 mm, 2.7 µm); gradient from 34% to 100% methanol (0.3% formic acid) at 0.6 mL/min, 40 °C.
• Mass Spectrometry: Shimadzu LCMS-8060 with heated electrospray ionization, rapid polarity switching (5 ms), up to 555 MRM transitions/s, scan speed 30 000 u/s.
• MRM Optimization: Two transitions per analyte in positive/negative modes.

Main Results and Discussion

The method achieved full separation of all analytes within five minutes. Calibration was linear from 100 ng/mL down to low-ppb or sub-ppb levels (0.0391 ng/mL for some). Limits of quantitation in neat standard ranged from 0.0391 to 10 ng/mL. In direct tap water analysis, trimethoprim (1.6 ppb), erythromycin (3.4 ppb) and fluoxetine (3.2 ppb) were detected; other targets remained below detection.

Benefits and Practical Applications

• High throughput enabling rapid screening of drinking water samples.
• Minimal sample preparation reduces analysis time and matrix effects.
• Sub-ppb sensitivity supports environmental surveillance and compliance monitoring.

Future Trends and Potential Applications

Potential developments include matrix validation, expansion to additional CECs, online preconcentration and adoption of high-resolution MS for non-target screening. The approach can be extended to wastewater, surface and groundwater monitoring.

Conclusion

An ultra-fast five-minute LC-MS/MS method was developed for simultaneous quantification of EPA 1694/6810 contaminants in drinking water, offering high sensitivity and throughput with minimal preparation. It is well suited for routine environmental monitoring.

Reference

Lieberman RA, Post J, Edwardsen J, Lipps W, Gilles C. A Rapid LCMS Method for Evaluation of EPA 1694 and 6810 Contaminants in Drinking Water. ASMS Poster ThP 130, Shimadzu Scientific Instruments; 2015.