you should not store DPPH for longer than a day as it degrades rapidly. But I would guess that a glass bottle should suffice
To prepare a DPPH radical solution, dissolve DPPH powder in a solvent like methanol or ethanol to a concentration of around 0.1-0.2 mM. Mix well until the solution is completely dissolved. The solution can be stored in the dark and at low temperature to protect it from light.
To prepare a 1 mM DPPH radical solution, dissolve 3.94 mg of DPPH (2,2-diphenyl-1-picrylhydrazyl) in 1 liter of solvent (typically methanol or ethanol). This will result in a concentration of 1 mM (molecular weight of DPPH is approximately 394.3 g/mol).
To prepare a 0.1M DPPH (2,2-diphenyl-1-picrylhydrazyl) solution, you would weigh 3.83 grams of DPPH powder and dissolve it in 1 liter of solvent (typically ethanol or methanol). Make sure to wear appropriate personal protective equipment and handle the chemical in a well-ventilated area.
To prepare a 0.2 millimolar (mM) DPPH solution in ethanol, you need to dissolve 0.2 millimoles of DPPH in a final volume of 1 liter of ethanol. First, calculate the molecular weight of DPPH (usually around 394.33 g/mol) to determine the mass needed to dissolve in ethanol. Then add this mass of DPPH to ethanol and make up the volume to 1 liter.
I really dont know people
Common reagents used in the estimation of antioxidants include DPPH (2,2-diphenyl-1-picrylhydrazyl) reagent, Folin-Ciocalteu reagent, and Trolox standard. These reagents are utilized in assays such as DPPH radical scavenging assay, total phenolic content assay, and oxygen radical absorbance capacity (ORAC) assay to measure the antioxidant capacity of compounds.
Scavenging capacity (%) = 100 - [(absorbance of sample - absorbance of blank) × 100/absorbance of control] The tests were done in triplicate. The IC50 values were calculated by linear regression of plots, where the abscissa represents the concentration of the tested plant extracts and the ordinate the average percent of scavenging capacity. The concentration of sample required to scavenge 50% of DPPH (IC50) were determined.
For corn syrup: it is fructose and glucose - C6H12O6Canadian maple syrup: Twenty-three phenolic compounds were isolated from a butanol extract of Canadian maple syrup (MS-BuOH) using chromatographic methods. The compounds were identified from their nuclear magnetic resonance and mass spectral data as 7 lignans [lyoniresinol (1), secoisolariciresinol (2), dehydroconiferyl alcohol (3), 5′-methoxy-dehydroconiferyl alcohol (4), erythro-guaiacylglycerol-β-O-4′-coniferyl alcohol (5), erythro-guaiacylglycerol-β-O-4′-dihydroconiferyl alcohol (6), and [3-[4-[(6-deoxy-α-l-mannopyranosyl)oxy]-3-methoxyphenyl]methyl]-5-(3,4-dimethoxyphenyl)dihydro-3-hydroxy-4-(hydroxymethyl)-2(3H)-furanone (7)], 2 coumarins [scopoletin (8) and fraxetin (9)], a stilbene [(E)-3,3′-dimethoxy-4,4′-dihydroxystilbene (10)], and 13 phenolic derivatives [2-hydroxy-3′,4′-dihydroxyacetophenone (11), 1-(2,3,4-trihydroxy-5-methylphenyl)ethanone (12), 2,4,5-trihydroxyacetophenone (13), catechaldehyde (14), vanillin (15), syringaldehyde (16), gallic acid (17), trimethyl gallic acid methyl ester (18), syringic acid (19), syringenin (20), (E)-coniferol (21), C-veratroylglycol (22), and catechol (23)]. The antioxidant activities of MS-BuOH (IC50 > 1000 μg/mL), pure compounds, vitamin C (IC50 = 58 μM), and a synthetic commercial antioxidant, butylated hydroxytoluene (IC50 = 2651 μM), were evaluated in the diphenylpicrylhydrazyl (DPPH) radical scavenging assay. Among the isolates, the phenolic derivatives and coumarins showed superior antioxidant activity (IC50 < 100 μM) compared to the lignans and stilbene (IC50 > 100 μM). Also, this is the first report of 16 of these 23 phenolics, that is, compounds 1, 2, 4−14, 18, 20, and 22, in maple syrup.
Besides (-)-epicatechin, epicatechin-(4β-8)-epicatechin (procyanidin B2), epicatechin-(4β-6)-epicatechin (procyanidin B5), epicatechin-(4β-8, 2β-O-7)-epicatechin (proanthocyanidin A2) and epicatechin-(4β-8)-epicatechin-(4β-8)-epicatechin (procyanidin C1), which were isolated before from Adansonia digitata [1], in this work an A-type proanthocyanidin trimer, i.e. epicatechin-(4β-8)-epicatechin-(4β-8, 2β-O-7)-epicatechin, tetrameric procyanidin D1, i.e. epicatechin-(4β-8)-epicatechin-(4β-8)-epicatechin-(4β-8)-epicatechin and a polymeric compound were isolated from the pericarp (fruit wall) of the fruits for the first time from this plant [2]. The antioxidant activity of different fractions and pure compounds was experimentally evaluated in the DPPH· assay. The ethyl acetate fraction, and most of the isolated compounds displayed a high activity (IC50 2.40-9.60µg/ml) compared with the reference antioxidant [3] Trolox (IC50 12.18µg/ml) as a standard.Acknowledgements: University of Antwerp Belgium, Prof. Dr. Pieters L. and Prof. Dr. Apers S. for NMR and MS spectra measurements.References: 1. Escribano-Bailon, T., et al. (1992)J. Agric. Food Chem. 40: 1794-1799.2. Esterhuyse, N. et al. (2001) Remarkable Trees of South Africa. Briza Publications, Pretoria.3. Cos, P. et al. (2002). Free Rad. Res. 36: 711-716.