A spectrophotometer, often referred to simply as a "spec" is a highly versatile piece of equipment that can be found in many different types of labs. Spectroscopy is the study of the interaction of light (reflectance or transmittance) with compounds. A spec is able to very finely measure the intensity of light at specific wavelenths, which will change in direct relation to the compounds within a solution. Each aspect that may be measured on a spectrophotometer will involve specific protocols for extraction. Often a technician will build a calibration curve by measuring absorbance values of known dilutions of the substance of interest. Unknown samples can then be measured and the reported absorbance for each sample will directly correlate back to the standard curve.

Spectrophotometer station

Our spec is considered a UV/Vis instrument, meaning that it can measure in wavelengths both in the UV and visible ranges of the light spectrum. Ours is also special because it can measure both via a cuvette (single sample) or a plate (able to hold 96 samples which are all read within a brief moment). Here the instruement is shown with the plate ready to be read. 

Spectrophotometer

table

 

Tests we currently run on our spec can be found in the table below:

  Wavelength 1 Wavelength 2 Wavelength 3 Cuvette or Plate Aspect Measured
Soluble protein  215 nm 225 nm  ...  Cuvette % S. Protein
 Wort & Beer Color  430 nm  ...  ...  Cuvette Color (SRM)

a & b acids (hops) 

 275 nm  325 nm 355 nm  Cuvette

% a acids

% b acids

Hop Storage Index

Anthocyanin

(purple antioxidant found in some colored barleys)

  535 nm ...  ...  Plate  Antocyanin (mg/kg)