CDS Empore 2240 Environmental SDB-XD Disks are made of polystyrenedivinylbenzene (SDB-XD) with a 12 μm particle size for solid phase extraction (SPE) of non-ionic surfactants. These disks offer broad chemical compatibility and are suitable for environmental sample preparation across a wide pH range from 1 to 14. Ideal for samples requiring retention of non-polar and non-ionic analytes.