The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1994
Filed:
Jul. 23, 1993
Joseph Stefkovich, Franklin, NJ (US);
Alfonso Liu, Boonton, NJ (US);
Whatman, Inc., Clifton, NJ (US);
Abstract
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.