Pyrrolizidine Alkaloids in the Food Chain: Development, Validation, and Application of a New HPLC-ESI-MS/MS Sum Parameter Method

Contamination of food and feed with pyrrolizidine alkaloids is currently discussed as a potential health risk. Here, we report the development of a new HPLC-ESI-MS/MS sum parameter method to quantitate the pyrrolizidine alkaloid content in complex food matrices. The procedure was validated for honey and culinary herbs. Isotopically labeled 7-O-9-O-dibutyroyl-[9,9-H-2(2)]-retronecine was synthesized and utilized as an internal standard for validation and quantitation. The total pyrrolizidine alkaloid content of a sample is expressed as a single sum parameter: retronecine equivalents (RE). L-d/L-q for honey was 0.1 mu g RE/kg/0.3 mu g RE/kg. For culinary herbs, 1.0 mu g RE/kg/3.0 mu g RE/kg (dry weight, dw) and 0.1 mu g RE/kg/0.3 mu g RE/kg (fresh weight, fw) were determined, respectively. The new method was applied to analyze 21 herbal convenience products. Fifteen products (71%) were pyrrolizidine alkaloid positive showing pyrrolizidine alkaloid concentrations ranging from 0.9 to 74 mu g RE/kg fw.