Extraction of Semi-volatile Organic Compounds in Drinking Water with NEW Atlantic® ReadyDisk C18 Solid Phase Extraction Disks

Significance of the Topic

Drinking water monitoring for semi-volatile organic compounds is critical for human health and regulatory compliance. EPA Method 525.2 outlines SPE-GC/MS protocols to quantify pollutants at trace levels. The development of robust, user-friendly extraction media enhances laboratory throughput and data reliability.

Objectives and Study Overview

This application note evaluates the performance of the new Atlantic ReadyDisk C18 for extracting a broad panel of semi-volatile organics from 1 L drinking water samples. Key goals include assessing recovery, precision, method detection limits (MDLs), and blank contamination under EPA 525.2 conditions.

Applied Methodology and Instrumentation

Sample Preparation and Extraction

• 1 L water samples acidified to pH <2 and spiked with surrogate and internal standards.
• SPE conditioning: sequential washes with ethyl acetate, methylene chloride, methanol, and water on ReadyDisk C18.
• Automated extraction on Biotage Horizon 5000: sample loading (~70 mL/min), air-drying (600 s), and stepwise elution (ethyl acetate, methylene chloride, 1:1 EtOAc/MeCl).
• Concentration on Biotage Horizon DryVap with DryDisk membranes to ~0.9 mL, final volume adjusted to 1.0 mL.
• External standard addition and transfer to 2 mL GC vials.

Instrumental Analysis

• GC/MS: Agilent 6890 GC coupled to 5975C MSD, splitless injection (1 µL), ZB-SemiVol column (30 m × 0.25 mm × 0.25 µm), helium carrier at 1 mL/min.
• Oven program: 60 °C (2 min), 20 °C/min to 270 °C, 6 °C/min to 320 °C (3 min hold).

Main Results and Discussion

Blank Contamination

• Six laboratory reagent blanks (LRBs) showed no detectable carry-over for target analytes, confirming system cleanliness.

Accuracy and Precision

• Five laboratory fortified blanks (LFBs) at 5 µg/L yielded average recoveries of 70–130% for all but three compounds; overall mean recovery was 101.1%.
• Relative standard deviations (RSDs) ranged from 3.4% to 20.1%, meeting the <30% criterion.
• Low recoveries observed for hexachlorocyclopentadiene (54.9%), atraton (42.0%), and prometon (54.6%), attributed to thermal/photo-degradation and acid-induced ionization.

Method Detection Limits

• Seven replicate LFBs at 0.5 µg/L on three days produced MDLs between 0.06 µg/L and 0.29 µg/L for most analytes, calculated using Student’s t (99% CI).

Benefits and Practical Applications

The Atlantic ReadyDisk C18 offers a plug-and-play SPE format that streamlines sample preparation, reduces solvent use, and delivers reliable recoveries and low MDLs. Its integration with automated Biotage platforms supports high-throughput water quality testing in environmental, industrial, and regulatory laboratories.

Future Trends and Opportunities

Emerging directions include

• Novel sorbent chemistries for broader contaminant classes (polar, charged analytes).
• Integration with on-line SPE and tandem mass spectrometry for real-time monitoring.
• Miniaturized, field-deployable SPE devices for remote water analysis.
• Data analytics and machine learning to optimize extraction parameters and predict method performance.

Conclusion

The new Atlantic ReadyDisk C18 coupled with Biotage automation exhibits robust performance for semi-volatile organic extraction from drinking water under EPA 525.2. It delivers accurate recoveries, consistent precision, and low detection limits in a user-friendly format, making it suitable for routine environmental monitoring.

References

• United States Environmental Protection Agency. Method 525.2: Determination of Organic Compounds in Drinking Water by Liquid–Solid Extraction and Capillary Column GC/MS, Revision 2.0.