Vial Caps-Membrane Combination
Original Publication Date: 1988-Feb-01
Included in the Prior Art Database: 2005-Feb-14
Vials containing chemical samples to be analyzed are used in liquid chromatography automatic sampling devices. Such vials must be easily, but properly, sealed to prevent both evaporation and contamination of the chemical compounds contained within each vial. For a vial that is to be used one time, the vial cap can include a simple thin seal of a chemically inert material, as shown in Fig. 1. In this case, it is not important that the seal within the vial cap will be broken by a single needle puncture. Specifically, Fig. 1 shows a cross-section of vial cap 10 which includes molded membrane 12 that is made of a chemically-inert material, such as TEFLON* or polypropylene. Membrane 12 is approximately 1.8 mils thick at its center and gradually becomes thicker (along its radius) until it becomes approximately 3.