Michael Thomas
4/13/2015
Professor: Dr. Allen
Introduction
Instrument Schematic
Agilent 9459
PerkinElmer Lamda 20
The instrument used to conduct this experiment are the Agilent 9459 and the Lambda 20.The Agilent 9459 light source for the UV wavelength range is a deuterium lamp. As a result of plasma discharge in a low pressure deuterium gas, the lamp emits light over the 190 nm to approximately 800 nm wavelength range.The Lambda 20 spectrometer features a scanning double-beam, all-reflecting optical system with microprocessor. The monochromator is a holographic concave grating with 1053 lines/mm in the center. It contains two light sources a deuterium lamp and a halogen lamp. The wavelength range of the Lambda 20 is 190 to 1100nm. UV-Vis spectrometry is governed to comply with Beer’s law, which states that absorbance of light is directly proportional to the thickness of the media through which the light is being transmitted multiplied by the concentration of absorbing chromophore; that is, A = εbc where A is the absorbance, ε is the molar extinction coefficient, b is the thickness of the solution, and c is the concentration.
Beer’ law can also be described as A = abc = log(100/%T) 2 - log %T
A = absorbance a = absorptivity b = light path of the solution in cm c = concentration of the substance of interest
%T = per cent transmittance—the ratio of transmitted light to incident light
Chromophores are electrons and a series of atoms that form a specific portion of an organic molecule that causes a unique color orientation. A know chromophore is chlorophyll, the unique color specified for chlorophyll is green. Chlorophyll is the molecule that absorbs sunlight and uses its energy to synthesize carbohydrates from CO2 and water. There is a relationship that exists between chromophore and chlorophyll. Chromophore is the pigment molecule that is responsible for the chlorophyll color. It possesses two orbital’s that determines the difference in which energy falls within the light spectrum. Isotonix is an example of a chromophore. The Isotonix OPC-3 supplements are scientifically-advanced formulas designed to give your body the maximum benefit from vitamins and minerals. Isotonix offers a complete array of products designed to improve and maintain human health. An example of how Isotonix improves and maintains human health is that its aids in the maintenance of maintaining healthy cholesterol levels. The purpose of this lab is to obtain absorbance of various pigments using UV-Vis spectrophotometry. My hypothesis states if dilutions occur then the absorption and concentration of that sample will decrease.
Materials
Isotonix OPC-3
Standard solution prepared in 1.0582g in 250mL
6 cubits
Agilent 8453 UV-visible spectroscopy system
Tape
Marker
Distilled water
Graduated cylinder
Beakers
Pipettes
Methodology
1.) Took 3mL of standard solution and put it in a graduated cylinder.
2.) Took 1mL out of the 3mL in the graduated cylinder and placed the 1mL into a cubit.
a. Labeled the cubit as 1
3.) Transferred 1mL of standard solution from the graduated cylinder into a flask and filled the flask up to the line with distilled water.
a. Took 1mL of this solution and placed it into a cubit.
b. Labeled cubit as 2
4.) Took 1mL of the dilute and transferred it into another flask then filled it up to the line with distilled water.
a. Took 1mL of this solution and placed it into a cubit.
b. Labeled cubit as 3
5.) Took 1mL of the dilute and transferred it into another flask then filled it up to the line with distilled water.
a. Took 1mL of this solution and placed it into a cubit.
b. Labeled cubit as 4
6.) For sample A
a. Took 1mL of standard solution and transferred it into a beaker and added 1mL of distilled water.
b. Took 1mL of this solution and placed it into a cubit.
c. Labeled cubit as A
7.) For sample B
a. Tooke 1mL of sample A and transferred it into a beaker and added 1mL of