Chapter 2. Colorimetric reactions in soil allelochemical analysis

SAMPIETRO, D.A.; SGARIGILA, M.A.; SOBERÓN , J.R.; VATTUONE, M.A.

Soil Allelochemicals

Studium Press LLC

Lugar: Houston; Año: 2011; p. 25 - 53

Ultraviolet and visible (UV-Vis) absorption spectrophotometry refers to techniques that measure the attenuation of a beam of light after it passes through a sample. UV and Vis light regions are a small section of the electromagnetic spectrum and cover wavelenghts from 185 to 380 nm and from 380 to 800 nm, respectively. Spectrophotometers, photoelectrically measure the amount of light absorbed by a sample with respect to an appropriate “blank”. Modern spectrophotometers split the incident light into different wavelengths and measure the intensity of that radiation. Colorimetric measurements often involve the reaction of colourless substances under analysis with specific reagents. This allows the formation of coloured complexes with absorbance maxima at wavelengths comprised in the visible light. This chapter provides general spectrophotometric/colorimetric based methods available for analysis of soil allelochemicals and related substances.