System and Method of Measuring Contaminants in a Substantially Translucent Material, Such as Water

A method of measuring the quantity of analyte in at least partly translucent material, wherein both an absorption and a phase difference for different wavelengths one after the other is measured such that a composition and quantity of different analytes can be determined, the method comprising:

• successively providing light radiation, from one or more light radiation sources, at a first wavelength and a second wavelength;
• simultaneous transmitting, by a first waveguide and a second waveguide, the light radiation at each wavelength provided from the one or more light radiation sources, wherein the first waveguide is a reference waveguide and the second waveguide is a sensing waveguide;
• and
• measuring, by a measuring means, a phase difference between light radiation waves from the reference waveguide and the sensing waveguide after passage of the light radiation waves in a single direction through the reference waveguide and the sensing waveguide, wherein:
• the sensing waveguide extends to the measuring means through a quantity of analyte in at least partly translucent material;
• and
• the reference waveguide extends to the measuring means through a reference environment external to the quantity of analyte in the at least partly translucent material, wherein the reference environment does not include the analyte or another instance of the analyte or the at least partly translucent material or another instance of the at least partly translucent material.