Dioxin Analysis: The current dioxin scandal has created a great disturbance in Germany, but fortunately, specific improvement measures in the field of foodstuffs inspections have also followed on as the result. Accordingly, on 2^nd February, the Federal cabinet adopted some changes to legislation concerning foodstuffs and fodder, including a disclosure obligation for private laboratories, and the setting-up of a dioxin early warning system. GIT spoke to Dr. Hans-Joachim Hübschmann and Dr. Kyle D´Silva from Thermo Fisher Scientific about the current requirements for the analysis of dioxin and other POPs (Persistent Organic Pollutants) and measures to improve workflows.

Dr. Hübschmann, the topic of dioxin is one that has been treated very sensitively in Germany, possibly as a reaction to the 1976 Seveso catastrophe. Why is it like this, and actually how great is the risk for consumers, in your estimation?

H.-J. Hübschmann: Of course the sensitivity springs from the fact that the toxicity of dioxin - for consumers - is a very difficult topic to approach. The way it operates is completely different from the normal perception of the toxicity of a substance. Whilst there are many substances that can be extremely poisonous for us, the damage caused by dioxins is long-term because it is cumulative. However, this long-term effect has hardly been taken into account in the discussion at the present time. Naturally, the concern about damage to health arises from the anticipation of a direct effect - except that there is no direct effect if I eat an egg in which the maximum threshold has been exceeded. Here, the maximum acceptable intake of dioxins in food comes up for discussion, although in everyday life and in practical terms it is very hard for us to measure it.

Consequently, the objective of foodstuffs & fodder inspections has to be the banning of accumulated substances from our environment. And this is also required by the UN Stockholm Convention. In the long-term, accumulation over a prolonged period will give rise to the health risks that have been discussed. The strict analytical monitoring of dioxins and other toxins over the last 20 years has demonstrably led to a marked reduction in such substances in the environment and hence also in our foods.

Lower levels of dioxin have prompted laboratories and apparatus manufacturers to require that apparatus should be able to measure these lower levels.

Precisely what levels of concentration are we presented with at the present time?

H.-J. Hübschmann: Absolute concentrations in the range of between 10 and 100 femtograms are being measured. These are the lower levels which analysers have to indicate at the present time. Naturally, the sample can also be concentrated. But that would run counter to the requirement for a rapid reaction, in other words the more sensitive instrumentation provides better results thanks to improved quality and also precision. And it provides such results more rapidly, too, because it can deal with smaller sample quantities.

Accordingly, as in the present case, we are concerned with more than merely detecting amounts that exceed the limits of the threshold. The long-term prevention of dioxin in the environment also includes regularly monitoring the background levels. In this context, we measure concentrations that are markedly below the maximum level in order to detect and to eliminate sources of pollution. These concentrations are detected in terms of the EU "action level". When this level is exceeded, we are obligated to detect and eliminate the cause. Research into causes includes examining the range of congeners, the variously chlorinated individual compounds, because this sample is influenced by various processes and biological causes and consequently enables insight into the source of pollution.

In the course of implementing Minister Ilse Aigner's 14-point plan, goals include improved dioxin monitoring. Does this mean quicker and more sensitive instrumentation, and more efficient workflows?

H.-J. Hübschmann: Yes. In the present case, we have seen how meat has been sold within 1 to 2 days, in respect of which there has been a suspicion that it might have been contaminated. However, it has unfortunately taken several days before the results were available. That - of course - explains the concern for expediting the achievement of effective inspection of these analysis processes.

Does this mean that the challenges reside more in the preparation of specimens or in analysis itself?

K. D´Silva: The tricky point is the preparation of the samples. For two reasons, this is a limiting factor: firstly, the preparation of samples is necessary in all cases, and also I have to concentrate the sample and remove it from its usually fatty surrounding matrix. Accordingly we have to ask: up to what level should I apply purification? If we use instrumentation which needs good sample preparation in order to function reliably, then I may need 2 to 3 days for the purification of the sample, although the measurement itself will then take place relatively quickly. If the objective is rapidity, which is of course the case for dioxin screening, then we need a desktop system such as Thermo Fischer Scientific's TSQ Quantum XLS. This is capable of analysing relatively unprepared samples for purposes of monitoring the maximum level. Accordingly, the all-important time gage and the necessary productivity for screening is achieved.