The Analysis of Chlorinated Dioxins, Difurans and Biphenyls in Edible Oils

Oral Presentation

Prepared by R. Addink
Toxic Report LLC, 580 Pleasant St, 2nd Fl, Watertown, MA, 02472, United States

Contact Information:; 617-393-1713


Polychlorinated dibenzo-p-dioxins and furans are a group of 210 compounds, of which 17 are considered toxic. These have a 2,3,7,8-chlorine substitution pattern and are of great concern to human health. Twelve polychlorinated biphenyls (out of a total of 209 compounds) have also been identified as human toxins. All these analytes bioaccumulate in adipose tissue and end up in food supplies. For this reason, the FDA and EU have established strict regulations for monitoring of food products for human consumption, in particular edible oils. Manual extraction of oils is a time-consuming procedure delaying lab turnaround times. The following procedure utilizes an automated sample clean-up system for same day analysis.

5 g of various oil matrices (lard, olive oil, corn oil, cod oil, red palm oil, unrefined pumpkin oil, unrefined vegetable oil) were spiked with 13C labeled standards, diluted into hexane and drawn up in a gas-tight syringe. Columns (acid-base-neutral silica, alumina and carbon) of the automated chromatography clean-up system were conditioned; samples were loaded across the ABN silica columns, eluted onto the alumina columns and then onto the carbon column using dichloromethane (fraction # 1). The carbon column was eluted with toluene collected as fraction # 2. The fractions were reduced in volume and analyzed with high-resolution GC/MS.

Recoveries for 13C PCBs were between 64-82% (averages per congener) and 70-82% for 13C PCDD/Fs. Detection limits for native species measured were < 0.5 pg/g oil. With a total processing time of less than 2.5 hours, the automated column chromatography system and concentrator deliver an efficient, completely automated sample prep process for edible oils.