Abstract: 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.

Abstract: 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.

Abstract: Cell-specific ligands comprising conjugates of saccharides and amino acids or peptides are synthesized from amino acids such as ornithine, lysine, peptides such as dilysine, diornithine or oligolysine and selected saccharides having reactive functional groups protected by appropriate blocking groups. Such glycopeptides are useful as tissue specific substances, which when coupled with bioactive materials through metabolizable or hydrolyzable linkages, deliver such bioactive materials to the selected site. In this manner, antiinflammatory drugs such as dexamethasone are linked through a metabolizable or hydrolyzable linkage and on administration to an animal suffering from inflammatory disease carries the drug to the site of inflammation for intracellular release. Other examples include the macrophage ligand N.sup.2 -N.sup.2, N.sup.6 -Bis-[3-(.alpha.-D-mannopyranosylthio)propionyl]-6-lysyl-N.sup.6 -[3-(.alpha.-D-mannopyranosylthio)propionyl]-L-lysine, 5, which when coupled to .beta.