Pesticides in Food

Pesticides in the broader sense are considered all crop protection products and all other pesticides. More understandable are maybe the terms with the following examples: to combat blight on grape vines a crop protection product is used, and to combat worms in apples, pears or the cankers in cabbage, a pesticide is used. Each analysis requires the provision of a representative sample from the entire sample amount. Therefore, as a rule larger amounts of the product are usually available and it has to be ensured that through comminution and sample dividing, that a representative sample is added to the analysis instrument.

Tomato plants are treated with various pesticides. Hereby the spray chemicals end up on directly on the fruit, as well as directly in the soil and therefore indirectly via the transport of nutrients into the fruit. The consumer though desires unpolluted food. The production of food in the demanded quality is without the use of pesticides impossible. Consequently the necessity arises to inspect food in regards to possible residues. Often the sought after substances are temperature sensitive. This plays a major part during the preparation of the sample.

Preparing tomatoes for analytical purposes is possible with the Mortar Mill PULVERISETTE 2, if the tomatoes are chopped into small chunks and embrittled with liquid nitrogen. For this application, the Fritsch GmbH offers as accessories for the Mortar-Mill, a grinding bowl completely made of stainless steel. This bowl can be cooled down with liquid nitrogen and during the comminution liquid nitrogen may also be added. Therefore an absolutely cryogenic comminution in liquid nitrogen is possible. After a few minutes a fine homogenous powder is obtained and a small sample amount can be weighed in for analysis.