Post-Lab 6: Determination of Fructose Content in Honey

69% glucose + fructose

Honey contains _____

Diastase, catalase, β-glucosidase

Common enzymes of honey

Ketohexose

Fructose is a _____

Spectroscopy

Deals with the production, measurement, and interpretation of spectra arising from the interaction of electromagnetic radiation (light) with matter

UV-Vis Spectroscopy

Spectroscopy utilizing radiation in the UV-Vis range

200 nm to 700 nm

Electromagnetic radiation in the UV-Vis portion of the spectrum ranges in wavelength from _____ to _____

200-350 nm; 350-700 nm

The UV range runs from _____; the Vis range runs from _____

Cuvette

A sample-holding cell or _____ should be chosen after the general spectral region to be used in a spectrophotometric measurement has been determined

does not absorb radiation

The sample-holding cell should be composed of a material that _____ in the spectral region being used

Quartz or fused silica

Sample-holding cells that do not absorb radiation may be composed of _____

Silicate glass

For the Vis range, cells made of _____ are appropriate and inexpensive plastic cells are also available for some application

Directly

Under appropriate conditions, absorbance is (directly/inversely) proportional to the concentration of the absorbing species in the solution

• This relationship is only applicable to dilute solutions, up to approx. 10mM for most analytes

Calibration curve

• Used to determine the concentration of unknown sample solution by measuring its absorbance

• Used to establish the relationship between analyte concentration and absorbance

• Constructed by plotting the absorbance (y-axis) against the corresponding concentrations (x-axis)

  • under appropriate conditions, it should be linear