A dual-mode spectrophotometer for measuring an optical property of a sample, comprising: a first optical conduit having a transmitting end; a first pedestal having a first pedestal surface (A') coupled to said first optical conduit having a transmitting end; a base plate; a second optical conduit having a receiving end; a second pedestal having a second pedestal surface (A") mechanically coupled to said base plate and configured to receive a first liquid sample, said second pedestal surface (A") being coupled to said second optical conduit having a receiving end, wherein said second pedestal surface (A")is further operable so as to adjust a separation between said first and said second pedestal surfaces at a variable distance to pull said first liquid sample into a column so as to be contained by surface tension, thereby providing an optical path with said transmitting end of said first optical conduit and said receiving end of said second optical conduit for photometric or spectrometric measurement; a linear actuator having a shaft, the second pedestal being coupled to the shaft so as to enable translation of the second pedestal and provide for said variable distance with respect to said first pedestal to enable differential absorbance path lengths; a configured plate; a sensor arranged to sense a distance to said configured plate so as to enable computation of a resultant translation indicative of the said variable distance; a vessel holder configured with a recessed guide means, said vessel holder configured to be removably coupled to said base plate; and a sample vessel configured to be resiliently secured within said recessed guide means, said sample vessel being configured for containing a second liquid sample therein and configured with at least two window means therein, thereby also providing an optical path for photometric or spectrometric measurement. a first optical conduit having a transmitting end; a first pedestal having a first pedestal surface (A') coupled to said first optical conduit having a transmitting end; a base plate; a second optical conduit having a receiving end; a second pedestal having a second pedestal surface (A") mechanically coupled to said base plate and configured to receive a first liquid sample, said second pedestal surface (A") being coupled to said second optical conduit having a receiving end, wherein said second pedestal surface (A")is further operable so as to adjust a separation between said first and said second pedestal surfaces at a variable distance to pull said first liquid sample into a column so as to be contained by surface tension, thereby providing an optical path with said transmitting end of said first optical conduit and said receiving end of said second optical conduit for photometric or spectrometric measurement; a linear actuator having a shaft, the second pedestal being coupled to the shaft so as to enable translation of the second pedestal and provide for said variable distance with respect to said first pedestal to enable differential absorbance path lengths; a configured plate; a sensor arranged to sense a distance to said configured plate so as to enable computation of a resultant translation indicative of the said variable distance; a vessel holder configured with a recessed guide means, said vessel holder configured to be removably coupled to said base plate; and a sample vessel configured to be resiliently secured within said recessed guide means, said sample vessel being configured for containing a second liquid sample therein and configured with at least two window means therein, thereby also providing an optical path for photometric or spectrometric measurement.