Fenazaquin solution in methanol is primarily used as an analytical standard in laboratory settings for the detection and quantification of fenazaquin residues in environmental and agricultural samples. It serves as a reference material in chromatographic techniques such as HPLC and GC-MS to ensure accurate measurement of the active ingredient in formulations or on treated crops. This solution is also utilized in research to study the stability, degradation, and distribution of fenazaquin in various matrices. Due to its solubility in methanol, it allows for precise dilution and consistent delivery in analytical workflows, making it essential for quality control in pesticide testing and regulatory compliance.