This mixture of anions—fluoride, chloride, bromide, and sulfate—finds application in analytical chemistry for ion interference studies and calibration of ion-selective electrodes. The combination helps assess the selectivity of sensors in multi-ion environments, simulating real-world samples such as environmental water or biological fluids. It is also used in water quality testing to evaluate the performance of purification systems in removing various ionic contaminants. In industrial processes, such mixtures can model complex brines for testing corrosion resistance of materials or optimizing separation techniques like ion exchange and electrodialysis.