Material: PP columns with PE filter elements. Further attractive products to complete your chromatography laboratory can be found on our Chromatography page! SPE polypropylene columns ROTI ® X Bond PSA (Diamino - QuEChERS) Ethylenediamine- n -propyl modified silica gel (PSA = Primary-Secondary Amine), weak anion exchanger (WAX). Similar to ROTI ® X Bond NH2. For the extraction of strong acids and polyacidic compounds from aqueous samples. Alternatively, it can be used as a polar sorbent to extract polar analytes from non-aqueous matrices. Also suitable for complexation with certain metal cations. Alkylated amine sorbent that contains two different amino functionalities. Due to the presence of primary and secondary amino groups (with pKa values of 10.1 and 10.9 respectively), PSA has higher ion exchange capabilities and strong hydrogen bonds. PSA has a significantly higher carbon load than most amino functional sorbents and is a good choice for polar compounds.