A portable, inexpensive and microcontrolled spectrophotometer based on white LED as light source and CD media as...

Area of Science:

• Analytical Chemistry
• Instrumentation

Background:

• Spectrophotometry is crucial for chemical analysis.
• Existing commercial spectrophotometers can be expensive for small laboratories.

Purpose of the Study:

• To develop a portable, microcontrolled, and low-cost spectrophotometer (MLCS).
• To validate the MLCS for determining food colorants and Fe(2+) concentrations.

Main Methods:

• Utilized a compact disc (CD) as a diffraction grating and a light-emitting diode (LED) as a light source.
• Employed a phototransistor and a programmable interrupt controller (PIC) microcontroller.
• Analyzed synthetic food colorant samples and oral restorative solutions for Fe(2+).

Main Results:

• The MLCS demonstrated accurate determination of tartrazine, sunset yellow, brilliant blue, and allura red.
• Fe(2+) concentrations in oral solutions were reliably measured.
• No significant differences were found when compared to commercial spectrophotometers (HP and Micronal).
• High precision was achieved with a relative standard deviation (R.S.D.) below 1.0% for all analytes.

Conclusions:

• The proposed MLCS is a cost-effective and accurate instrument for spectrophotometric analysis.
• It is suitable for routine analysis, research, and educational purposes in resource-limited settings.
• The instrument's components are inexpensive and readily available.