Lanthanide Label Array Method for Identification and Adulteration of Honey and Cacao

A generic, cost-effective, and simple method has been developed to fingerprint liquids to differentiate food brands and ingredients. The method is based on a label array using nonspecific long lifetime unstable luminescent lanthanide labels. The interaction between the liquid sample and the label is typically detrimental to the luminescence of the unstable chelate leading to a sample-dependent luminescence-intensity array. The label-array method is a unique approach as the array of unstable chelates is extremely inexpensive to produce and possesses high sensitivity due to spectral as well as unstable structural properties of the lanthanide label. The global method has been applied to distinguish commercial honey and cacao brands to demonstrate its feasibility as honey and cacao are among the most adulterated food products.