Evaluation of an analytical method for cyanogenic compounds in beans and surveillance of cyanogenic compounds in beans.

The performance characteristics of an analytical method for cyanogenic compounds were evaluated. Specifically, we tested the trueness, repeatability and intermediate precision of the method using a spectrophotometric-based detection system for 4-pyridinecarboxylic acid and pyrazolone after steam distillation. The pH adjustment of the distillate was revealed to affect the trueness of the measurements. A pH of approximately 6 was found to be optimal. The targeted quantitation limit of the cyanide ion was set to 5 mg/kg. The performance of the method was evaluated using beans spiked with cyanide ion at one to two times the quantitation limit (5-10 mg/kg). The trueness of the method was between 78-90%, and the repeatability and intermediate precision were between RSD 1.2% to 6.0%. A surveillance of cyanogenic compounds in beans retailed in Japan was then carried out. All the results were below the quantitation limit of 5 mg/kg.