3: Caffeine serial dilution and analysis using (UV-vis) spectroscopy
- Page ID
- 450907
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After completion of the UV-vis module you will be able to:
- Use analytical techniques to create a serial dilution starting from pure, solid material. (Use an analytical balance, volumetric glassware, and pipettes)
- Operate an Agilent Cary double beam UV-vis spectrometer and collect UV-visible absorption data.
- Use a UV-visible spectrometer to identify the wavelength of maximum absorption of a light-absorbing analyte, and select the appropriate wavelength for quantitative analysis.
- Create a series of standard solutions using serial dilution, generate a calibration curve, and validate the calibration using a validation standard (control) solution of the analyte.
- Determine if UV-vis is an appropriate technique to quantitate a single analyte in a mixture.
- 3.2: Absorbance and Beer's Law
- In absorption spectroscopy a beam of electromagnetic radiation passes through a sample. Much of the radiation passes through the sample without a loss in intensity. At selected wavelengths, however, the radiation’s intensity is attenuated. This process of attenuation is called absorption.
- 3.3: UV/Vis Instrumentation
- Earlier we examined Nessler’s method for matching the color of a sample to the color of a standard. Matching colors is labor intensive for the analyst and, not surprisingly, spectroscopic methods of analysis were slow to find favor. With the introduction of photoelectric transducers for ultraviolet and visible radiation, and thermocouples for infrared radiation, modern instrumentation for absorption spectroscopy routinely became available in the 1940s—further progress has been rapid ever since.