Analysis of Polychlorinated Dibenzo-p-dioxins, Furans and Biphenyls in Drinking Water with Semi-Automated Solid Phase Extraction Using EPA Method 1613

Challenges and Opportunities for Solid Phase Extraction
Oral Presentation

Prepared by R. Addink
Toxic Report Laboratories, 580 Pleasant St, Watertown, MA, 02472, United States


Contact Information: [email protected]; 617-393-1713


ABSTRACT

Continued interest in Persistent Organic Pollutants (POPs), such as polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs), and biphenyls (PCBs), has led to a variety of automated systems for the Solid Phase Extraction (SPE) of various kinds of water samples, including drinking water. To meet demands for a lower cost method that requires less financial investment than the automated systems, we developed a simple semi - automated system which is faster and cheaper while yielding high quality data in accordance with EPA 1613 method.

Six 1 L water samples were acidified to pH ~2, spiked with 5-10 mL methanol and with 13C labeled PCDD/F and PCB standards. The sample bottles were attached to the SPE system and sample rinse bottles were filled with 25 mLs dichloromethane. C-18 cartridges were installed in each of the six positions.

The next steps were divided in two stages. Stage 1: cartridges conditioned under vacuum with dichloromethane, methanol and water (5 mLs each), followed by loading the cartridges, drying (nitrogen) and automated sample bottle rinse (dichloromethane). Stage 2: bottle rinses eluted across the C-18 cartridges and Na2SO4 cartridges and the eluent collected for analysis.

Collection tubes with Direct-to-Vial connections were put in an automated concentrator, pre-heated for 15 minutes at 50 C, and heated in sensor mode under 7-10 psi nitrogen which assured automatic shut-off at 1 mL. They were further reduced in volume further in a vial evaporator and spiked with recovery standards. Analysis was done on a high res GC/MS.

Excellent 13C labeled recoveries were seen for tetra-CDD/Fs thru octa-CDD/Fs between 75-105%. For the WHO-12 and indicator PCBs the 13C recoveries were between 70-90%.

The semi-automated SPE system produces reliable and reproducible results for dioxins, furans and PCBs in drinking water. The system is cheaper than fully automated SPE equipment.