Used as a reference standard in analytical chemistry for the accurate identification and quantification of trans-1,4-Dichloro-2-butene in environmental and industrial samples. Commonly employed in gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) to calibrate instruments and validate testing methods. Particularly useful in monitoring air and water pollutants, as this compound may appear as a byproduct in chemical manufacturing or as a degradation intermediate of certain chlorinated solvents. Ensures precision in quality control and regulatory compliance testing.