الفهرس 
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Abstract
In this thesis, an innovative, homemade, low-cost, portable, precise and accurate camera-based platform was designed, and successfully applied to the assessment of iron and speciation of chromium, in environmental samples. Iron was determined based on its reactions with 1,10-phenanthroline, 2,4,6-Tris(2-pyridyl)-s-triazine (TPTZ) or salicylate; while chromium was determined based on its reaction with Diphenylcarbazide (DPC), following the recommendations of ASTM, standard methods for the examination of water and wastewater, or alike reference protocols. The platform design, evaluation, optimization, application and validation have been thoroughly investigated and incorporated in respective recommended procedures.
The current work opens a new era in analytical laboratories by introducing and comparing for the first time the application of various non-uniform color spaces (RGB, CMY, XYZ, Yxy) and uniform color spaces (L*a*b*, LUV, Hunter LAB, LCH, HSL, HSV, ELab and ELUV) as signaling tools.
Images were captured using a digital camera, a smartphone camera or a computer scanner. Captured digital images were analyzed initially based on the standard RGB color mode. The obtained RGB intensities were then converted into the corresponding color absorbance values of various non-uniform and uniform color spaces. A plot of Iron or chromium concentration versus color absorbance, derived from digital images, gave linear relationships, limit of detections and limits of quantifications competing with and sometimes surpassing the corresponding data obtained with sophisticated UV-Vis or flame atomic spectrometers.
The proposed platform was conveniently applied to the assessment of Iron in various environmental samples such as natural water, soils, pharmaceutical preparations, plant materials and food samples. Moreover, the developed platform was applied to the speciation of chromium in natural and wastewaters. Analytical data obtained with the proposed platform were validated by comparison with the corresponding spectrophotometric data of the respective standard method. Moreover, the camera-based platform was successfully applied to the study of the composition and formation constants of the formed iron(II)-phenanthroline, iron(II)-TPTZ and iron(III)-salicylate complexes using the molar ratio and continuous variation methods, thus adding another originality aspect to our camera-based platform.