EPA method 526: Selected semi-volatile organics using automated SPE

Scope

This application note will outline methods for the extraction of selected semi-volatile organic compounds (SVOCs) as outlined in EPA method 526 using Biotage automated or manual SPE solutions and the DryVap® Concentrator System. The first section will highlight the use of the Biotage® Horizon 5000 fully automated extraction system and the method used for this application. Additionally, there will be an Application Modification section that will highlight the use of the Biotage® VacMaster® Disk for this application.

Introduction

Method 526 is a gas chromatography/mass spectrometry (GC/MS) method for the determination of selected semi-volatile compounds in raw and finished drinking waters. This method efficiently extracts analytes using the Biotage® Horizon 5000 with an Atlantic® 47 mm polystyrene divinylbenzene (DVB) disk. The disk is extracted with using Ethyl Acetate (EtOAc) and Methylene Chloride (DCM). The extract is then dried and concentrated using the DryVap® Concentrator System coupled with DryDisk ® technology to a final volume of 1.0 mL. Final analysis is performed by GC/MS.

Instrumentation

•  Biotage Instruments
  »  Biotage® Horizon 5000 Automated Extraction System
  » DryVap® Concentrator System
  » DryDisk® Separation Membranes
  » Atlantic® DVB SPE disk (47 mm)
• GC/MS system

Method summary

1. Obtain 1 L samples and spike any laboratory control or matrix spike samples.

2. Purge the Biotage® Horizon 5000 system using the method listed in table 1.

3. Place the sample bottle on the Biotage® Horizon 5000 Automated Extraction System and place the Atlantic® DVB disk in the standard 47 mm disk holder. Attach collection vessels to the system.

4. Extract the sample using the method in table 2 and collect the final sample extract.

5. Pour the extract into the DryDisk® reservoir and start the DryVap®.

6. Concentrate the sample down to a final volume of 1 mL.

7. Final analysis is performed by GC/MS

Application modifications

Biotage® VacMaster™ Disk method summary

1. Repeat the following steps for each active Biotage® VacMaster™ Disk station.

2. Setup the VacMaster Disk manifolds ensuring all waste lines and vacuum lines are attached. Set the vacuum pump to -24”Hg.

3. Prepare the disk holder assembly (47 mm): ensure the support screen is flat in the centre of the disk holder. Place the Atlantic® DVB Disk on top of the support screen with the ripples of the disk on top and add any prefilters on top of the disk. Place the disk holder assembly on the VacMaster Disk manifold ensuring there is a tight seal with the luer fitting.

4. If using the multifunnel, place onto the disk holder assembly. If not using the multifunnel, omit those directions throughout the method.

5. Condition the SPE Disk:
                 a. Guide for each conditioning step in table 3 below:
I. Measure the appropriate VOLUME of SOLVENT into a graduated cylinder and pour into the disk holder assembly.
II. Using a Nalgene Wash Bottle (phthalate free), rinse the multifunnel and disk holder in a circle for about 3 seconds using the same SOLVENT (approximately 5 additional mL).
III. SATURATE the disk for the indicated time (in SECONDS). (Saturate means: quickly turn the knob to the appropriate waste destination and back to the “OFF” position. This brings the solvent into the disk media bed).
IV. SOAK the disk for the indicated time (in SECONDS).
V. DRAIN to the appropriate waste destination for the indicated time (in SECONDS). Switch to the “OFF” position.

6. Load the Sample:
a. For multifunnel: quickly and efficiently angle the bottle to rest on the multifunnel upside-down.
b. For no multifunnel: pour a portion of the sample into the disk holder.
c. Adjust the vacuum between -10”Hg and -15”Hg for sample load (please note, if the sample is flowing too slowly, the vacuum can be increased). Drain the sample to “AQUEOUS” waste. Continue to pour the sample into the disk holder ensuring the disk does not go dry or overflow for the duration of sample load.

7. Air Dry the SPE Disk:
a. Return the vacuum to -24”Hg and continue to air dry the SPE disk to “AQUEOUS” waste for an additional 600 SECONDS. Switch to the “OFF” position.
b. Remove the sample bottle from the multifunnel if it was used.

8. Elute the SPE Disk: (Please note: the elution solvent will go into the collection flask inside the chamber, not to waste containers)

a. Place a clean 125 mL 24/40 tapered Erlenmeyer flask or 40 mL VOA vial using the VOA vial insert into the Biotage® VacMaster™ Disk collection chamber. Place the cover on the chamber. Remove the disk holder assembly and place the disk holder assembly into the luer fitting on top of the collection chamber. Attach the luer fitting of the collection chamber assembly onto the manifold.

b. Guide for each elution step in the table below:
I. Measure the appropriate VOLUME of SOLVENT into a graduated cylinder, pour into the sample bottle, and swirl around. Pour the solvent in the sample bottle into the disk holder assembly.
II. Using a Nalgene Wash Bottle (phthalate free), rinse the multifunnel and disk holder in a circle for about 3 seconds using the same SOLVENT (approximately 5 additional mL).
III. SATURATE the disk for the indicated time (in SECONDS) to “ORGANIC”.
IV. SOAK the disk for the indicated time (in SECONDS).
V. DRAIN to “ORGANIC” for indicated time (in SECONDS). Switch to the “OFF” position.
VI. Remove the chamber lid to release the vacuum from inside the chamber.

Literature number: AN010