| 摘要 |
The subject of the present licence is based on the use of a potent oxidant, chromium peroxide (Cr(02)2. H20, or briefly CrO5) This compound is a product of the following reaction : Chemical Compound + ammonium salt (reaction 1) Chromium peroxide isa deep blue product, relatively stable in polar organic solvents, with a maximum absorption at = 569 nm in isoamyl alcohol, and at = 566 nm in propylene carbonate. The acidic environment for the reaction was provided by acids such as H2SO4 andHCIO4. When the products of the reaction `1 are mixed with an organic solvent (eg. isoamyl alcohol), then the formed CrOs moves and dissolves in the organic phase (solution 1) of the bi-phasic solution, the aqueous phase of the solution containing the reagents. The antioxidant compounds of a certain substance or biological sample, added to the above solution 1, inhibit the formation of the deep blue CrOs. The extent of the inhibition of the color formation in solution 1, measured by means of a spectrophotometer, represents the antioxidant capacity (or the oxidative status) of the sample under measurement. Initially, if hydrogen peroxide (H2O2J is not added to the solution 1 , then chromium peroxide is not produced (see reaction 1) and the organic solution is not coloured deep blue (solution 2). If in this colourless solution 2 is added a substance or a biological sample containing hydrogen peroxide or other peroxides, then it becomes deep blue , due to the formationof chromium peroxide by the reaction of ammonium dichromate with the sample peroxide, in the presence of H2SO4 (see reaction 1). The intensity of the formatted blue colour, spectrophotometrically measured, reflects the sample content in peroxide compounds and its oxidant capacity. With the above information in mind, the assay was graded , regarding the antioxidant capacity (solution 1), in correlation with various concentrations of a- tocopherol (vitamin - ), and regarding the oxidant capacity (solution 2) of various samples, in correlation with various concentrations of hydrogen peroxide (H2O2). The assay displays the lowest detection level of the antioxidant capacity of sample equal to 10 10 -tocopherol, and the lowest detection level of the oxidant capacity of a sample equal to 10 `9 H2O2 ( sensitivity of the assay). |
