Method and apparatus for spectrophotometry of turbid media

An apparatus for analysis of light that has passed through a turbid sample in a cuvette, said turbid sample having a wavelength-dependent absorption coefficient and a wavelength-dependent reduced scattering coefficient, said apparatus comprising:

• a self-calibrating hybrid spectrophotometer that comprises:
• a receptacle for receiving said cuvette,
• first and second optodes that are configured to permit light to enter said cuvette when said cuvette has been received in said receptacle,
• third and fourth optodes that are configured to permit light to leave said cuvette when said cuvette has been received in said receptacle, and
• an illumination controller that is configured to control delivery of light to a selected one of said first and second optodes,
• wherein light entering at a source optode selected from the group consisting of said first and second optodes is received at said third and fourth optodes after having interacted with said turbid sample along different inter-optode paths having different path lengths,
• wherein measurements made at said third and fourth optodes in response to having selected said first optode for delivery of light into said cuvette provide a first slope of optical transmittance as a function of path length,
• wherein measurements made at said third and fourth optodes in response to having selected the second optode for delivery of light into said cuvette provide a second slope of optical transmittance as a function of path length, and
• wherein said self-calibrating hybrid spectrophotometer is configured to use said first and second slopes to identify a third slope, said third slope being indicative of said absorption coefficient and said reduced scattering coefficient of said turbid sample.