Used as a reference standard in analytical laboratories for the accurate identification and quantification of 3,4-xylenol in environmental, industrial, or biological samples. Commonly applied in gas chromatography (GC) and high-performance liquid chromatography (HPLC) to calibrate instruments and validate test methods. Ensures reliability in monitoring xylene-derived phenolic compounds, which may arise from industrial emissions, chemical degradation, or metabolic processes. Also supports quality control in chemical manufacturing and environmental testing where precise concentration measurements are critical.