Implementation of novel SPME Arrow for the trace-level analysis of taste and odor compounds in drinking water

Significance of the Topic

Decaying algae blooms release earthy and musty compounds like MIB and geosmin that cause taste and odor events in drinking water. Although not strictly regulated, their presence impacts consumer perception and drives water utilities to develop sensitive detection techniques.

Objectives and Study Overview

This study evaluates the performance of a novel SPME Arrow configuration coupled with GCMS for trace-level quantification of 2-methylisoborneol (MIB) and geosmin in drinking water.

Methodology and Instrumentation

Solid phase microextraction was performed using a PDMS/DVB/Carboxen SPME Arrow.
Shimadzu GCMS-QP2020 NX with AOC-6000 autosampler enabled automated extraction and analysis.
Extraction conditions included equilibration at 65 °C for 10 min and adsorption for 30 min, followed by thermal desorption at 250 °C for 10 min.
GC separation employed an SH-Rxi-624Sil MS column with helium carrier gas under constant linear velocity, temperature ramp from 50 °C to 250 °C.
MS detection monitored characteristic ions for MIB, geosmin, internal standard (IBMP), and surrogate (IPMP).

Key Results and Discussion

Calibration was linear (R2 = 0.99) over 0.5 to 100 ng/L for both analytes using IBMP as internal standard.
Limits of detection were determined at 0.05 ng/L, two orders of magnitude below odor thresholds.
Reproducibility at 10 ng/L showed RSD of 15% for MIB and 12% for geosmin based on eight consecutive injections.
Precision at the lowest concentration (0.5 ng/L) yielded RSD of 0.2% for MIB and 5% for geosmin.

Benefits and Practical Applications

• Rapid analysis: overlapping extraction and GCMS analysis achieves 30 min per sample.
• High sensitivity and robustness suitable for routine T&O monitoring.
• Automated workflow reduces manual handling and improves throughput.
• Applicable for drinking water utilities, QA/QC laboratories, and environmental monitoring.

Future Trends and Potential Applications

Advances may include field-deployable SPME Arrow devices, new sorbent chemistries for broader odorant coverage, integration with high-resolution MS, and real-time T&O event surveillance.

Conclusion

The implemented SPME Arrow-GCMS method delivers fast, sensitive, and reproducible detection of trace MIB and geosmin in drinking water, offering a powerful tool for managing taste and odor concerns.

Instrumentation Used

• Shimadzu GCMS-QP2020 NX
• AOC-6000 autosampler
• SPME Arrow with PDMS/DVB/Carboxen coating
• SH-Rxi-624Sil MS column

References

No external literature was cited in the source document.