Thermo Fisher puts ‘global’ carbendazim orange juice issue to the test

20 Feb 2012

Thermo Fisher Scientific says it has internally validated a faster and more accurate new method for detecting residue levels of carbendazim in oranges and orange juice than one technique now being used by the US FDA to test Brazilian imports.

The company said its Food Safety Response Centre in Dreieich, Germany, had “worked around the clock” to develop a rapid and reliable method that the industry could use to address what had now become a “global” concern with the fungicide carbendazim.

Explaining the automated online sample preparation method (its new ‘Transcend TLX’ system) in a white paper, Laslo Hollosi et al. from Thermo Fisher said the firm’s method “enabled convenient, fast and cost-effective automated determination of carbendazim and [fungicide] benomyl in oranges and orange juice”.

“Based on the short total run time and a simple online sample preparation technique, 100 samples per day can be analysed at a level of 0.01 mg/kg [or 10 parts per billion, the Food and Drug Administration's (FDA's) maximum residue level or MRL] with faster and more precise analysis compared to the QUECHERS (Quick, Easy, Cheap, Effective, Rugged and Safe) technique,” they added.

Discussing the carbendazim issue, Vincent Paez, director of food safety programme at Thermo Fisher Scientific, said in a company podcast: “We think that this is a global issue, not just between Brazil and the US.

Significant economic issue

Paez added: “Everyone is looking at orange juice coming from Brazil. So we thought that this was global in nature, it halts trade in orange juice, so it’s significant economically. We thought that the number of samples that would be analysed to get all this resolved would be siginificant.”

Explaining the advantages of the new TLX method, he said: “We developed a method and validated it [following IUPAK and AOAC protocols for single laboratories], and it’s a very fast method compared to the methods that are used today."

“There is an existing validated method out there today that’s being used by the FDA and others, and it has a sample preparation technique called QUECHERS.”

“This analytical technique is called LC-MS/MS, which is a very common technique in laboratories," Paez added.

“It is easy, cheap and reliable, but it’s very manual. What we did with this method in the FSRC is automate it with a sample preparation instrument called Turboflow. It’s a way to do online sample preparation.

Automated process

Paez said Thermo Fisher used the same technique – liquid chromatography with triple quadrupole mass spectrometry - but had automated the process.

“Instead of shaking the tube with your hands, you introduce the sample into the Turboflow instrument, and it will do the online extraction and sample clean up, then you introduce the clean extract mass spectrometer (the triple quadrupole),” he said.

Paez added: “Automating things enables the laboratory to analyse many samples in a day. There is also also a quality advantage. Think of the things that can go wrong when you have a manual process. When you have a machine doing it, it’s more repeatable.”

As a chemical fungicide, carbendazim is used to control fungus and mould growth, but is not registered for use with US citrus crops.

Source: Thermo Fisher Scientific