Abstract

Background and Objective: Laser spectroscopy is becoming an increasingly paramount analytical tool. Scientists today have at their disposal many various types of laser-based analytical techniques. In this article, the possibility of using capabilities of a laser to analyze and find the concentration of Serum Total Protein (STP) was studied.

Materials and Methods: The laser system includes a diode laser with 532 nm wavelength, with maximum output power being 5 mW. Laser bandwidth ranges around (524 nm – 546 nm) experimentally justified using a monochromator. A simple variable resistance with a range from zero to10Ω for obtaining a range of laser output power, detector, parallel variable resistance with the range from zero to 5 kΩ and meter for measuring the percentage of transmittance. The absorption spectroscopy of STP samples was measured by double beam spectrophotometer.

Results: Maximum absorbance of STP is at the range (520-580 nm) and the peak at (500) nm. Laser system measurements included the study of absorbance of STP as a function of cuvet thickness, transmittance as a function of cuvet thickness and absorbance as a function of laser power. In order to ascertain our calculations, the results have been compared with the results of the spectrophotometer. The Relative Standard Deviation (RSD%) values are about (0.67-17.18).

Conclusion: The diode laser system is a highly efficient and easy system and allows access to a range of powers. Since the divergence of the laser beam is very low. All results are in good agreement with conventional double beam spectrophotometer.

Keywords: Absorption spectroscopy, blood, laser spectroscopy, serum total protein, spectrophotometer, transmittance.