<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31317389</termId><termName>size exclusion chromatography</termName><termType>PT</termType><termNote><![CDATA[ Size exclusion chromatography (SEC) is a type of chromatography that separates compounds based on differences in molecular size in solution. It uses a separation column containing a porous, semisolid medium which retards transport of larger particle while allowing small molecules to pass quickly through. SEC (also known as gel permeation chromatography) is primarily used for characterizing molecular weight distribution of synthetic polymers. ]]></termNote><termCreatedDate>2026-03-30 20:25:28</termCreatedDate><relation><relationType>UF</relationType><termId>31317390</termId><termName>GPC</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31317391</termId><termName>SEC</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31317392</termId><termName>chromatography, size exclusion</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31317393</termId><termName>gel permeation chromatography</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31317394</termId><termName>size-exclusion chromatography</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31304416</termId><termName>chromatography</termName><termType>PT</termType></relation></term>  </Zthes>