Analysis of Semi-Volatile Organic Compounds (EPA Method 525) Using A Highly Versatile C18 Based Sorbent

Don Shelly, Shawn Ream, and Craig A. Perman, UCT, LLC

Materials and Instruments

• UCT ENVIRO-CLEAN®* 83 mL Extraction Cartridge ECUNI525, (1500 mg)

• Column: Restek Rtx® 5 ms** 30 meter × 0.25 μm × 250 μm

• Hewlett Packard 5890 Series II with a 5971A MSD

GC–MS Conditions

• Injector: 250 °C, Oven: 50 °C, Initial 5 min, Final 300 °C @ 6 °C/min, Hold 7.4 min

• Head Pressure: 9 psi He

• MSD detection: Mass range scan: 50–550, EI Mode, Temperature 300 °C

Sample Preparation

• A 1-liter DI water sample is adjusted to pH<2 using 6N HCl

Extraction/Elution

• Wash cartridge and apparatus using 10 mL of 1:1 ethyl acetate: methylene chloride. Dry by drawing vacuum.

• Condition cartridge by adding 10 mL methanol. Soak 1 min, add DI water then draw through by vacuum.

• Add 5 mLs of methanol to the 1 liter water sample and draw through cartridge at 50 mL/minute. Dry cartridge under vacuum.

• Rinse sample bottle with 10 mL ethyl acetate, transfer to cartridge, elute, and collect.

• Repeat 2 × 10 mL 1:1 ethyl acetate:methylene chloride.

• To dry eluant, filter through anhydrous sodium sulfate. Rinse with 2 × 3 mL aliquots of methylene chloride.

Evaporate

Concentrate under gentle stream of N₂ (< 40 °C) to 1 mL for analysis.

Results

Table I: Representative Table of Compounds

References

(1) Method 525.2 "Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary Column Gas Chromatography/Mass Spectrometry" Revision 2.0, National Exposure Research laboratory, US EPA, 1995.

* Further information on other 525 compounds analyzed with the ECUNI525 cartridge can be obtained from UCT.

** Rtx® is a registered trademark of Restek Corporation, Bellefonte, PA.

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