Increased capacity for analysing dioxins and dioxin-like PCBs

NIFES has recently installed an advanced new instrument at the Laboratory for undesirable substances, which will make it possible to analyse considerably more fish and seafood samples for environmental pollutants such as dioxins and dioxin-like PCBs.

Samples are already waiting in line to be analysed by the high-resolution gas chromatograph mass spectrometer (HRGC-HRMS). The high level of activity reflects an increased need for documentation on the content of dioxins and dioxin-like PCBs in fish and other seafood from Norwegian fishing areas. There are upper limits for these substances in seafood, set by the EU.

"The authorities, foodstuff manufacturers and consumers are all keen to have more information in this area", says Kåre Julsham, Head of Research in the Surveillance Research Programme at the National Institute of Nutrition and Seafood Research (NIFES).

NIFES has been analysing fish and seafood samples for dioxins and dioxin-like PCBs since 2001.

A very sensitive instrument

Dioxins and dioxin-like PCBs are found in small quantities in the environment and require advanced techniques in order to be determined. An HRGC-HRMS can establish the presence of dioxins and dioxin-like PCBs as small as one thousand millionth of a milligram.

"The sensitivity of the instrument can be illustrated as follows: If we say that the City Fjord outside Bergen measures 5 kilometres x 5 kilometres and is 100 meters deep, it will contain 2500 000 000 000 litres of water. 100 grams of sugar in this huge volume gives a concentration corresponding to the level of dioxins that we can measure", says Dr. Julshamn.

What happens in an HRGC-HRMS?

In an HRGC-HRMS the substances in the sample are separated at boiling point in the GC part, while the molecules are pulverised and the mass is determined in the MS part. Based on a mass frequency that is typical for dioxins and dioxin-like PCBs it is possible to measure the level in the sample.

Dioxins and dioxin-like PCBs

According to the report from the Norwegian Scientific Committee for Food Safety in 2006 ” “Fish and seafood consumption in Norway – Benefits and risks” dioxins, dioxin-like PCBs and methyl mercury represent the potentially highest risk with respect to pollutants in fish and other seafood. It is therefore important to monitor the level of these substances in seafood.

Which substances are found in seafood?

If you click on Seafood Data at NIFES’ homepage you can carry out your own search for data on both undesirable substances and nutrients in fish and other seafood.

The high-resolution gas chromatograph mass spectrograph recently installed at NIFES ’ Laboratory for undesirables weighs no less than 1 ton!