This mixture of anions—fluoride, chloride, nitrate, and sulfate—is commonly encountered in environmental and industrial water systems. It is particularly relevant in wastewater analysis, where the presence and ratio of these anions help assess contamination sources, such as industrial discharge, agricultural runoff, or seawater intrusion. Fluoride and chloride are often monitored in drinking water to ensure safety and compliance with health standards. Nitrate levels indicate potential agricultural pollution or sewage contamination, posing risks to human health and aquatic ecosystems. Sulfate is significant in corrosion studies and in the treatment of water due to its role in microbial sulfate reduction. The combined analysis of these anions is essential in environmental monitoring, water treatment processes, and quality control in chemical manufacturing. Ion chromatography is typically used to separate and quantify them accurately in complex matrices.