[1] Chem & Vet Untersuchungsamt Sigmaringen, HPLC LC MS, D-72488 Sigmaringen, Germany
[2] Univ Hohenheim, Inst Lebensmitteltechnol, D-70593 Stuttgart, Germany
[3] Eotvos Lorand Univ, Dept Organ Chem, H-1518 Budapest 112, Hungary
[4] Univ Hohenheim, Inst Chem, D-70593 Stuttgart, Germany