Automated Extraction and Clean Up of POPs Using a Green Low Solvent System

Advances in Sample Preparation and Clean-up
Oral Presentation

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


Contact Information: ruudaddink@toxicreports.com; 617-393-1713


ABSTRACT

Persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and biphenyls (PCBs) continue to attract interest around the world due to strict regulations in force in many countries. Rapid extraction, sample clean up, and analysis are therefore needed for many laboratories processing samples for POPs. In addition to processing times, solvent use is an important consideration as the cost of sample clean up involving large amounts of solvents can be very high.

A new integrated automated sample extraction and clean up system was developed, which allows for rapid extraction of the sample (time approximately one hour) and fast clean up (2 hours). Solvent consumption is limited to 120-200 mLs and no dichloromethane is used during the cleanup step. Our new fully automated system allows for sample turnaround times of only a few hours and same day analysis and results.

1-2 g of feed or sediment was mixed with Hydromatrix™ and spiked with 13C labeled standards. Samples were put in extraction cells. Pressurized Liquid Extraction with 50%/50% v/v dichloromethane/hexane (120oC, 1500psi, 20min) was carried out. The samples were then processed on the automated open column chromatography system using acid-base-neutral silica, carbon and alumina columns. A five-step program using hexane and toluene operates with about 120 mL of solvent used for standard column sets and 200 mLs for high capacity columns (up to 5 g of fat).

In addition to feed and sediment (extraction plus clean up), fatty acids and fish oil were run (clean up only). 13C isotope dilution standards recoveries were 75-110% for PCDD/Fs and 80-110% for PCBs.

The integrated PLE/Low Solvent EconoPrep gives excellent recoveries for a number of matrices. It is a green option with low electrical power use.