What is Mixed-Mode SPE? Mixed-mode solid-phase extraction (SPE) represents a sophisticated analytical technique that combines two or more distinct retention mechanisms within a single sorbent material. Unlike conventional SPE cartridges that rely on a single interaction type—such as reversed-phase (hydrophobic) or ion-exchange—mixed-mode sorbents integrate multiple binding mechanisms to achieve superior selectivity and cleanup for complex

Principles of Ion Exchange Chemistry Ion exchange solid phase extraction (SPE) represents one of the most selective and powerful sample preparation techniques available to analytical chemists. Unlike traditional reversed-phase SPE that relies on hydrophobic interactions, ion exchange SPE utilizes electrostatic interactions between charged analytes and oppositely charged functional groups on the sorbent surface. This fundamental

Chemical Design of HLB Polymer Hydrophilic-Lipophilic Balance (HLB) sorbents represent a breakthrough in solid-phase extraction (SPE) technology, first introduced in 1996 with Waters’ Oasis HLB. Unlike traditional silica-based sorbents, HLB polymers are constructed from a unique water-wettable copolymer that maintains stability across the entire pH range from 0 to 14. This innovative design eliminates the