Investigation of the herbicide glyphosate and the plant growth regulators chlormequat and mepiquat in cereals produced in Denmark.
An LC-MS/MS method for analysing glyphosate and aminomethylphosphonic acid (AMPA) in cereals was developed. The method is based on extraction with water and detection of the ions from the fragmentation m/z 170-->88 (glyphosate) and m/z 112-->30 (AMPA), using electrospray interface in the positive mode. Investigation from the harvests of 1998 and 1999 showed residues of glyphosate and/or its degradation product AMPA in more than half of the cereal samples produced in Denmark. The average concentration of glyphosate in 46 samples from the 1999 harvest was 0.11 mg/kg compared with 0.08 mg/kg for the 1998 harvest (n = 49). Thus, the figures were well below the maximum residue limit (MRL) and no violations were observed. The plant growth regulators chlormequat and/or mepiquat were investigated in cereals from the Danish harvest of 1999 where 83% of the samples contained chlormequat (n = 46) compared with 87% of the samples from the 1997 harvest (n = 52). The average concentration of chlormequat in 1999 was 0.32 mg/kg compared with 0.23 mg/kg in 1997. At 2.9 mg/kg, one sample of wheat bran was exceeding the MRL of 2 mg/kg for wheat. The intakes of the pesticides through the diet of cereals were estimated to comprise 0.04% of the acceptable daily intake (ADI) for glyphosate and 1% of the ADI for chlormequat for an adult Dane.
Granby
K
K
Institute of Food Research and Nutrition, Danish Veterinary and Food Administration, Søborg. kgr@fdir.dk
Vahl
M
M
D002716:Chlormequat / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003718:Denmark; D002523:Edible Grain / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives / Q000032:analysis*; D006540:Herbicides / Q000032:analysis*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008452:Maximum Allowable Concentration; D010880:Piperidines / Q000032:analysis*; D010937:Plant Growth Regulators / Q000032:analysis*; D015203:Reproducibility of Results; D000097797:Glyphosate
D002716:Chlormequat; D005998:Glycine; D006540:Herbicides; D010880:Piperidines; D010937:Plant Growth Regulators; D000097797:Glyphosate; C049449:mepiquat