Optical detection arrangement for small volume chemical analysis of fluid samples

摘要

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).