Contaminant analysis in complex matrices

This sheet was designed as a board game. The aim is to conduct an investigation in order to solve the conundrum.

Conundrum:
A cargo of green coffee beans from Latin America was refused on arrival in the port of Le Havre. Indeed, customs officers took a sample in order to verify if the shipment complied with European legislation, particularly with regard to pesticide residues and mycotoxins. As the results of the test revealed an abnormally high content of ochratoxin A (17.3 µg/kg), the cargo could not be unloaded. The company which had ordered this import contests these results. It has therefore requested a second opinion from an independent laboratory.
You are the person from this laboratory in charge of verifying the non-compliance of this cargo: it is up to you to conduct the investigation properly... Several clues will help you to make progress in this meticulous work.