Technique and system for coding and identifying materials
AssigneeCalifornia Institute of Technology
InventorsFrederick H. Shair, Peter G. Simmonds, Robert B. Leighton, Peter J. Drivas
Life of this patent
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Abstract
Microencapsulated spheroids containing a coded, volatile electron absorbing substance are dispersed into a material to be regulated such as crude oil in a tanker. Samples of the material such as an oil spill are collected and the source of the material is determined by electron capture gas chromatographic detection of the electron absorbing substance.
Claims12
A method of tagging a material for future identification, said material being selected from the group consisting of petroleum crude oil and refined liquid products thereof, comprising the steps of adding to said material microcapsules encapsulating a detectable amount of a readily analyzable coded substance not normally present as a component of said material, dispersing said microcapsules uniformly throughout said material, said microcapsules having low solubility in said material and low permeability to said substance, collecting a sample of said material containing said microcapsules dispersed therein, concentrating said microcapsules, releasing said tag substance from said microcapsules and analyzing said substance by electron-capture gas chromatography.
A composition of matter comprising a material to be identified in the future containing a dispersion of microcapsules encapsulating a coded, active tag substance consisting essentially of a compound not normally present as a component of the material and being readily detectable and analyzable when released from said microcapsule, wherein said material is selected from crude petroleum oil and refined liquid products thereof, said material contains no more than 10.sup..sup.-8 parts of said substance and said substance is a mixture of electron absorbing compounds each containing at least one electrophore selected from --CO.sup.. CO--, --CO.sup.. CH:CH--CO--, quinone, --NO.sub.2 and halogen, each of said compounds having a specific response to electron capture-gas chromatographic detection, and wherein said microcapsules have a wall thickness between 0.5 and 2 microns and a well characterized particle size between 5-50 microns, and said microcapsules have a density between 0.9 and 1.5 grams per cubic centimeter.
A composition of matter comprising a material to be identified in the future containing a dispersion of microcapsules encapsulating a coded, active tag substance consisting essentially of a compound not normally present as a component of the material and being readily detectable and analyzable when released from said microcapsule, wherein said material is selected from crude petroleum oil and refined liquid products thereof, said material contains no more than 10.sup..sup.-8 parts of said substance and said substance is a mixture of electron absorbing compounds each containing at least one electrophore selected from --CO.sup.. CO--, --CO.sup.. CH:CH--CO--, quinone, --NO.sub.2 and halogen, each of said compounds having a specific response to electron capture-gas chromatographic detection, and wherein said microcapsules have a particle size between 5-500 microns and a density between 0.9 and 1.5 grams per cubic centimeter.
A method of tagging a plurality of separate quantities of a material for future identification comprising the steps of
- preparing a plurality of separate quantities of encoded, detectable amounts of readily analyzable, volatile, electron absorbing, tag materials, each said tag material differing from every other tag material by the presence or absence of a selected number of substances having specific responses to electron capture-gas chromatographic detection,
- encapsulating each separate quantity of tag material in separate pluralities of microspheres,
- adding each separate plurality of microspheres to each separate quantity of material to be tagged, and dispersing said microspheres substantially uniformly throughout each said separate quantity of material.
A composition of matter comprising a material to be identified in the future containing a dispersion of microcapsules encapsulating a coded, active tag substance, said material having no more than 10.sup..sup.-8 parts of said substance, said substance comprising a mixture of electron absorbing compounds each containing at least one electrophore selected from --CO.sup.. CO--, --CO.sup.. CH:CH--CO--, quinone, --NO.sub.2, and halogen, each of said compounds having a specific response to electron capture-gas chromatographic detection.
A composition of matter comprising a material to be identified in the future containing a dispersion of microcapsules encapsulating a coded, active tag substance which is formed of telomers of the formula:
- SF.sub.5 (CF.sub.2).sub.n Z
- where n is an integer from 0-25 and Z is selected from F, Br or I.
Dependencies are inferred from the claim text.