A novel quality-by-design optimized spectrofluorimetric method for the sensitive determination of ricinine alkaloid in edible oils

Ricinine is an important biomarker used for detecting the exposure to castor bean products. The current study describes a highly sensitive and selective spectrofluorimetric approach to determine ricinine in various edible oils. It depends on measuring the native fluorescence of ricinine at 365 nm following excitation at 307 nm over a concentration range of 50.0-1200.0 ng/mL. The method displayed high sensitivity with quantitation and detection limits down to 19.56 and 6.46 ng/mL, respectively. The significant factors affecting the fluorescence of ricinine were optimized using 22 full factorial design. The proposed approach was successfully employed for ricinine determination in three types of edible oils with high percent recoveries and low S.D. values. The most important advantage of the developed method is the reduction of sample preparation steps, analysis time, and cost. Hence, it can be better suited for routine analysis and quality control of cooking oils adulterated with castor oil.