Project code: BfR-LMS-08-1322-281
Contract period: 01.01.2007
Purpose of research: Basic research
Malachite green (MG) is a triphenylmethane dye used to color materials such as cotton, silk, leather, and paper. MG is also used as a veterinary drug applied as topical antiseptic or to treat parasites, fungal infections, and bacterial infections in fish and fish eggs. Other applications are uses as biological stain, gain medium, to detect latent blood in forensic medicine, as pH indicator compound or even for the illegal coloring of foodstuffs. The metabolite leucomalachite green (LMG) is formed by the reduction of malachite green chloride and persists in the tissues of exposed fish. Legally, zero tolerance applies to all residues of MG and LMG in foodstuffs as MG is not registered for use with food producing animals worldwide. Nevertheless, consumers are exposed to residues of MG as demonstrated by frequent detects of MG residues in fish and fish products that may be due to illegal use but maybe also derive from additional environmental sources. In the EU, a legally non-binding “minimum required performance limit” (MRPL) of 2 µg/kg has been set as action limit for internationally traded food consignments. But technical feasibility alone and not potential health risks is the yardstick for the establishment of a MRPL which has never as a rule undergone a risk assessment! Thus, current data suggests that MG and especially LMG may be carcinogenic and also provided some evidence that they are in vivo mutagens. Information on practical importance and multiple uses and on possible environmental background contamination is missing. The project should provide some information about the accumulation of MG and LMG in eels from municipal waters, herrings from the Baltic Sea and mackerels from the Celtic Sea. Fishes are analyzed for residues of MG and LMG by using a validated, robust and highly sensitive method applying HPLC-MS/MS with SRM acquisition. The goal of this project is to exclude that represents a significant impact to the consumer’s exposure to MG residues and to get a comprehensive overview on the degree of contamination of wildlife fish by MG residues.