Using the Agilent 7696A Sample Prep WorkBench for the analysis of estrone by GC Triple Quadrupole Mass Spectrometry

Significance of the topic

The accurate detection of endocrine disruptors such as estrone in water is critical due to their persistence and potential ecological and human health effects even at trace levels.
These compounds from pharmaceutical and agricultural sources resist conventional treatment and can disrupt endocrine systems in wildlife and humans.

Objectives and Study Overview

This study demonstrates an automated workflow for preparing and analyzing estrone in aqueous samples using the Agilent 7696A Sample Prep WorkBench coupled with GC triple quadrupole mass spectrometry.
It aims to improve throughput, precision, and reproducibility of sample preparation including calibrator setup and derivatization.

Methodology and Instrumentation

• Sample preparation: Automated calibrator and derivatization (BSTFA/TCMS, pyridine, acetonitrile) on the 7696A WorkBench with heating at 60 °C for 30 minutes.
• GC/MS/MS analysis: Injection via cold split-less MMI, two 15 m HP-5MS UI columns in series, helium carrier gas, cryogenic focusing.
• Detection: Agilent 7000B Triple Quadrupole in EI mode using MRM transitions 342→257 and 342→244 m/z.

Instrumentation

• Agilent 7696A Sample Prep WorkBench
• Agilent 7890A GC with Multi-Mode Inlet and Purged Ultimate Union
• Agilent 7693A 150-position autosampler
• Agilent 7000B Triple Quadrupole GC/MS

Key Results and Discussion

• Recovery for estrone at 1 ng/mL was approximately 113–133% across replicates.
• Precision ranged from 3.3% to 6.9% RSD over five concentration levels (1–50 ng/mL).
• Calibration was linear (R² = 0.996) for 15 injections.
• Instrument detection limit estimated at 0.48 pg on column, consistent with literature MDLs.
• Automation reduced manual labor and potential errors while maintaining analytical performance.

Benefits and Practical Applications

• High throughput automated sample preparation enhances laboratory efficiency.
• Consistent derivatization and calibration improve quantitative reliability.
• Applicable to environmental monitoring, pharmaceutical quality control, and regulatory compliance.

Future Trends and Potential Applications

• Expansion to additional endocrine disruptors and complex matrices.
• Integration of online extraction and microextraction techniques.
• On-site and field-deployable automated platforms for rapid environmental screening.
• Coupling with high-resolution or ambient ionization mass spectrometry for broader analyte coverage.

Conclusion

The automated combination of the Agilent 7696A WorkBench and GC triple quadrupole MS delivers robust, reproducible, and sensitive analysis of estrone, addressing the growing demand for high-volume endocrine disruptor testing.

References

1. Trinh T., et al. Simultaneous determination of estrogenic and androgenic hormones in water by isotope dilution gas chromatography–tandem mass spectrometry. J. Chrom A. 1218 (2011) 1668–1676.
2. Wells G., Prest H., Russ C.W. Why use signal-to-noise as a measurement of MS performance when it is often meaningless. Agilent Application Note 5990-8341EN. Agilent Technologies, Inc. (2011).