Quantitative evaluation of sanguinarine as an index of argemone oil adulteration in edible mustard oil by high performance thin layer chromatography

A simple analytical procedure based on HPTLC method was developed for the detection of argemone oil adulteration in edible mustard oil using sanguinarine as an index of argemone oil adulteration (measured as % adulteration). The methodology required no elaborate extraction procedure. The quantitation was achieved by densitometric scanning of the chromatogram in fluorescence/reflectance mode. Dihydrosanguinarine concentration was determined after its conversion to sanguinarine by UV (366 nm) irradiation, for a period of 15 min. The limit of detection (LOD) of sanguinarine in argemone oil was estimated as 1 ng per 6 mm band with a signal-to-noise ratio of 3:1 and limit of quantitation in the samples was estimated as 3 ng per 6 mm band with a signal-to-noise ratio of 10:1. The total content of sanguinarine (sanguinarine + dihydrosanguinarine) in argemone oil samples were in the range of 4.84-5.79 mg/ml of oil. Standard sanguinarine was spiked to edible mustard oil at two levels (50 and 100 microgram/ml) and recoveries were found to be 79% and 82%, respectively. A linear regression plot (y = 40.44 (+/-0.014)x - 5.81 (+/-0.078)) was generated between the percent adulteration of argemone oil in edible mustard oil and the concentration of sanguinarine in the edible mustard oil spiked with various levels of argemone oil (1-30%). Analyzing the adulterated edible mustard oil samples collected from the area, wherein an outbreak of epidemic dropsy was reported in the recent past, validated this linear regression plot. The percent adulteration in these samples was found to be in the range of 1.22-8.77%. Food and forensic laboratories can use this method routinely in order to assess the adulteration of edible oils by argemone oil and in poisoning cases due to argemone oil toxicity.