Whatman Gmbh

Joseph Stefkovich

Alfonso Liu

James C Robbins

Walter Leon Jones, Jr

In accordance with the invention, an SPE extraction apparatus is provided with a new SPE disk which eliminates radial wicking and weeping and new disk holding apparatus which minimizes the indirect flow region and minimizes the number of sample transfers required. The new SPE disk encapsulates the sorbent/fiber matrix between two porous outer layers which can be filters, united into an essentially non-porous rim around the disk perimeter. The disk holder and ring seal against this disk rim so that the active central portion of the disk is held entirely within the direct flow path. Thus weeping and indirect flow loss are virtually eliminated. In a preferred embodiment, the apparatus eliminates the need to manually disassemble the apparatus while in use. Advantageously a flow control mechanism is incorporated into the disk holder to further minimize the amount of solvent needed for extraction.

Solid phase extraction disk and apparatus for enhanced recovery and

Solid phase extraction apparatus for enhanced recovery and precision

A solid phase extraction device has a solvent-compatible permeable membrane with a bubble point greater than the normal operating pressure differential used and a sorbent material retained by two disks or frits so that when pressure is applied, the sample to be processed will pass through the membrane, but the membrane will not permit air to pass therethrough, and the sorbent remains wet throughout the process. The device has an input port and an output port and operates to maintain a pressure differential between the ports. Sorbent material is entrapped between two disks or frits. Located above the sorbent material is a support having a grid surface. The support prevents the frit from 'riding up' the column of the barrel. Ultrasonically welded to the support is a solvent-compatible permeable membrane. The membrane is hermetically sealed to the support and the support is self-locked to the interior barrel of the device. When wetted, the membrane allows for the passage of matter, but prevents air from passing therethrough to the sorbent material. The sorbent material remains wet. With the sorbent material retained by the frits, the sorbent material will not escape to contaminate the filtrate.

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Franklin, NJ, United States of America

Joseph Stefkovich