Ontwsep™ TPR tea pesticide residue special column filler is made of three materials in a certain proportion and filled in layers. Its main function is to remove pigments and volatile organic compounds in tea leaves. It can remove organic acids, tea polyphenols, and other impurities without adsorbing target pesticides, thus ensuring the purification effect of samples and the recovery rate of target substances. 23204-2008, Determination of 519 pesticides and related chemical residues in tea by gas chromatography-mass spectrometry," and GB 23200.13-2016, 448 Pesticides and Determination of Relevant Chemical Residues by Liquid Chromatography-Tandem Mass Spectrometry.