The safety evaluation of food contact materials requires excluding mutagenicity and genotoxicity in migrates. Testing the migrates using in vitro bioassays has been proposed to address this challenge. To be fit for that purpose, bioassays must be capable of detecting very low, safety relevant concentrations of DNA-damaging substances. There is currently no bioassay compatible with such qualifications. High-performance thin-layer chromatography (HPTLC), coupled with the planar SOS Umu-C (p-Umu-C) bioassay, was suggested as a promising rapid test (~6 h) to detect the presence of low levels of mutagens/genotoxins in complex mixtures. The current study aimed at incorporating metabolic activation in this assay and testing it with a set of standard mutagens (4-nitroquinoline-N-oxide, aflatoxin B1, mitomycin C, benzo(a)pyrene, N-ethyl nitrourea, 2-nitrofluorene, 7,12-dimethylbenzanthracene, 2-aminoanthracene and methyl methanesulfonate). An effective bioactivation protocol was developed. All tested mutagens could be detected at low concentrations (0.016 to 230 ng/band, according to substances). The calculated limits of biological detection were found to be up to 1400-fold lower than those obtained with the Ames assay. These limits are lower than the values calculated to ensure a negligeable carcinogenic risk of 10⁻⁵. They are all compatible with the threshold of toxicological concern for chemicals with alerts for mutagenicity (150 ng/person). They cannot be achieved by any other currently available test procedures. The p-Umu-C bioassay may become instrumental in the genotoxicity testing of complex mixtures such as food packaging, foods, and environmental samples.

Preschool-aged children and non-pregnant women of reproductive age particularly in countries of a lower socio-demographic index may experience insufficient dietary vitamin A. Fortifying staple foods such as edible oils with vitamin A is a useful approach to reduce malnutrition. To enable better quality oil fortification, producers need reliable and inexpensive tools for assessment of the vitamin A contents of their products. A simple reversed-phase high-performance thin-layer chromatography fluorescence detection (RP–HPTLC–FLD) method was developed and studied for the quantification of vitamin A palmitate (VAP) in five edible plant oils. The challenging matrices of non-refined palm kernel oil and soybean oil, which are known to interfere with the accuracy of some easy-to-use test kits, were separated from VAP using the new RP–HPTLC–FLD method. The standard addition method provided good accuracy and acceptable calibration curves (coefficients of determination R² between 0.9874 and 0.9999) even for manual application. The developed RP–HPTLC–FLD method proved simple, robust, sustainable, cost-efficient, and suitable for low-tech (minimum equipment) on-site analysis. Graphical Abstract