<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">solid-phase microextraction</topic></authority><related type="broader"><topic>analysis and testing techniques</topic></related><related type="broader"><topic>sampling</topic></related><variant type="other"><topic>SPME</topic></variant><variant type="other"><topic>microextraction, solid-phase</topic></variant> <note xml:lang="en"><![CDATA[ Sample extraction technique used for chromatographic analysis of dilute solutions in difficult matrices, liquid and gaseous. Solid-phase microextraction (SPME) has two discrete steps. Extraction is achieved by solute absorption from the sample matrix into a thick layer of silicone or related adsorptive material. Analytes are then transferred into a chromatography inlet system by gaseous or liquid means.  ]]></note></mads>