Opaque additive to block stray light in teflon® af light-guiding flowcells
First Claim
Patent Images
13. A light-guiding apparatus comprising:
- a fluid channel bounded by at least one wall, the composition of said at least one wall having an index of refraction lower than an index of refraction of a fluid in said fluid channel and having an absorption coefficient sufficient to substantially attenuate light propagating through said walls;
an entrance for light, said entrance perpendicular to an axis of said channel;
an exit for light, said exit perpendicular to said axis; and
fluid inlet and outlet ports, whereby said walls and fluid effect guiding of said light by attenuated total reflection, said walls having minimal absorptive effect on the guided light.
2 Assignments
0 Petitions
Accused Products
Abstract
The present invention is directed to the use of a light absorbing wall material to eliminate stray light paths in light-guiding structures, such as those used for HPLC absorbance detection. More specifically, the present invention relates to the use of carbon-doped Teflon® AF, or “black Teflon® AF,” for all or part of the walls of a light-guiding flowcell adapted for use in HPLC absorbance detection.
31 Citations
30 Claims
-
13. A light-guiding apparatus comprising:
-
a fluid channel bounded by at least one wall, the composition of said at least one wall having an index of refraction lower than an index of refraction of a fluid in said fluid channel and having an absorption coefficient sufficient to substantially attenuate light propagating through said walls;
an entrance for light, said entrance perpendicular to an axis of said channel;
an exit for light, said exit perpendicular to said axis; and
fluid inlet and outlet ports, whereby said walls and fluid effect guiding of said light by attenuated total reflection, said walls having minimal absorptive effect on the guided light. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. An apparatus for housing a liquid sample and for exposing said liquid sample to light, said apparatus comprising:
a conduit having a wall formed of an amorphous fluoropolymer having a refractive index less than the refractive index of water and having an absorption coefficient of a magnitude such that when said conduit is filled with water, visible light and ultra-violet light can be transmitted, substantially without loss, along an axis of said conduit by attenuated total reflection and visible light and ultra-violet light are substantially completely absorbed in passage through the wall of said conduit.
-
24. A method of performing photometric analysis of a liquid sample comprising:
-
introducing said liquid sample into a conduit having a wall formed of an amorphous fluoropolymer having a refractive index less than a refractive index of water and having an absorption coefficient sufficient to substantially attenuate light propagation through said wall;
shining light axially onto said conduit filled with sample liquid;
receiving light transferred through said liquid sample at a detector; and
determining a concentration of said sample in said liquid by light absorption by the sample, whereby linearity of detection is improved. - View Dependent Claims (25, 30)
-
-
26. A set of light-guiding flowcells for a fluid comprising:
-
a set of channels formed in a substrate of material having an index of refraction lower than an index of said fluid and an absorption coefficient sufficient to substantially attenuate light propagating through said material;
a set of channel covers formed in a section of material having an index of refraction identical to said substrate material and an absorption coefficient sufficient to substantially attenuate light propagating through said material, said set of channel covers fixed to said set of channels forming a set of covered channels;
at least one covered channel having a fluid inlet and outlet port configured off an axis of said covered channel;
at least one covered channel having a source of light at a light entrance end and having a light exit end;
whereby said at least one covered channel and fluid effect guiding of said light by attenuated total reflection and said at least one covered channel has minimal absorptive effect on said light guided by internal reflection. - View Dependent Claims (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 27, 28, 29)
-
-
28-1. The set of light-guiding flowcells of claim 26 wherein at least one covered channel is configured as a separation column.
Specification