Ciba-geigy Corporation

Beat Krattiger

Alfredo E Bruno

Carlo S Effenhauser

Hans Peter Herzig

Francois Maystre

Martial Geiser

Philippe Nussbaum

An optical detection arrangement for small volume chemical analysis comprises a light source (22), a capillary tube (23) and a photoelectric detector (24). The arrangement of the light source (22) relative to the capillary tube (23) is such, that probing light (P) emitted from the light source (22) strikes a sample (S) to be analyzed, which is flowing through the capillary tube (23), whereas the photoelectric detector (24) is arranged relative to the capillary tube (23) such, that it is capable of detecting light comming from the capillary tube. The photoelectric detector (24) is connected with an evaluation electronics. Between the light source (22) and the capillary tube (23)the probing light (P) is guided essentially in a guiding means (26) which is made of a material having a refractive index gradient about perpendicular to the direction of propagation of the probing light (P), and which is connected to the capillary tube (23) such that probing light (P) exiting the guiding material (26) strikes the capillary tube (23). Preferably light emitting diodes (LEDs) or laser diodes are used as light source (22).

Optical detection arrangement for small volume chemical analysis of

An interferometric apparatus for monitoring changes of the refractive index of An interferometri1capillary tubes comprising a source of coherent light, which is arranged with respect to a capillary tube which is part of a capillary liquid chromatographic system or a capillary electrophoretic system, such that the coherent light beam strikes the capillary tube about perpendicular to its longitudinal extension. In the forward direction of the coherent light beam, behind the capillary tube, the apparatus comprises a photoelectric detector for monitoring a resulting interference fringe pattern and the shifts thereof, which is connected to an evaluation electronics. Between the light source and the capillary tube there is arranged a beam splitting optical element for generating a converging probe beam, which travels along a probe beam axis and strikes the capillary tube at its bore, and a converging reference beam, which travels along a reference beam axis, that extends generally parallel to the probe beam axis and is located in close vicinity to the probe beam axis, and which does not strike the capillary bore.

Interferometric apparatus for monitoring changes of the refractive index

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Riehen, Switzerland

Beat Krattiger