Development and validation of HPLC method for the determination of ferrocyanide ion in food grade salts

A rapid, simple, and reliable HPLC method was developed and validated to determine the presence of ferrocyanide ions (FeCNs) in food grade salts. An analytical column coupled with a guard column and mobile phase comprised of sodium perchlorate and sodium hydroxide (NaOH) were employed at a detection wavelength of 221nm. Samples were dissolved in 0.02M NaOH solution and filtered. For processed salts including herbs and spices, a C₁₈ cartridge was applied to minimize interference from salt matrices. The method validation was based on linearity, accuracy (recovery), precision, LOD, LOQ, and measurement uncertainty. This method exhibits good linearity from 0.1-10mg/L (r²=0.9999). The LOD and LOQ values were determined to be 0.02 and 0.07mg/kg, respectively. The FeCN recoveries in six salt matrices ranged from 80.3-102.2% (RSD=0.3-4.4%). These results indicate that the proposed method is suitable for FeCN ion determination in various food grade salts.