A tag is added to an asphalt additive, typically an anti-stripping agent. The additive dye is mixed with other components of an asphalt composition and melt processed at 300°F (149°C) or above to produce an asphalt composition. Presence of the tag to identify presence of the additive is performed by dissolving the asphalt portion of the composition in a water-immiscible solvent and then extracting the tag in an acidic aqueous solution and developing a color with a diazo compound.
Method for determining whether a fluid in an air-conditioning or refrigeration system has been altered
申请人:——
公开号:US20030096419A1
公开(公告)日:2003-05-22
A method for determining whether a fluid in an air-conditioning or refrigeration system has been altered is revealed. The method comprises preparing a non-radioactive label for a fluid used in the system, where the fluid is selected from a lubricant, a fluorescent dye and combinations thereof; adding a known quantity of the label to the fluid to form a labeled mixture of the fluid; performing an analysis of the labeled mixture to obtain a base-line profile of the labeled mixture; adding the labeled mixture to the system; providing the system to a user or customer; thereafter, performing an analysis of the fluid in the system to obtain a test profile; and determining whether the fluid in the system has been altered by comparing the base-line profile with the test profile of the fluid in the system.