Compute scavenging activity from corrected absorbance readings. Track Trolox equivalents, dilution effects, and sample basis. Save tables, print PDFs, and inspect response trends instantly.
| Sample | Control A | Sample A | Sample Blank | Reagent Blank | Dilution | Volume mL | Mass g | Slope | Intercept | Inhibition % | Equivalent per g |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Berry Extract | 0.820 | 0.410 | 0.030 | 0.020 | 5 | 10 | 1.5 | 0.045 | 0.010 | 52.50 | 303.70 µmol TE/g |
| Tea Infusion | 0.900 | 0.290 | 0.025 | 0.020 | 4 | 8 | 1.2 | 0.050 | 0.012 | 69.89 | 321.60 µmol TE/g |
| Herbal Powder | 0.760 | 0.520 | 0.040 | 0.015 | 3 | 12 | 2.0 | 0.040 | 0.008 | 35.57 | 115.65 µmol TE/g |
This table shows how corrected absorbance, dilution, and calibration can be combined into a comparable antioxidant capacity basis for different chemistry samples.
Corrected control absorbance = Control absorbance − Reagent blank
Corrected sample absorbance = Sample absorbance − Sample blank
Net response = Corrected control absorbance − Corrected sample absorbance
Percent inhibition = (Net response ÷ Corrected control absorbance) × 100
Equivalent concentration = (Net response − Intercept) ÷ Slope
Total equivalent in extract = Equivalent concentration × Dilution factor × Extract volume
Equivalent per gram = Total equivalent in extract ÷ Sample mass
Use a linear standard curve whose slope and intercept match the same response definition used here. The calculation works best for absorbance reduction assays such as DPPH or ABTS, where a lower corrected sample absorbance indicates stronger activity.
This approach is useful when you need a quick assay summary plus a mass-normalized equivalent value for comparing extracts, foods, beverages, plant materials, or formulation trials.
Antioxidant capacity describes how strongly a sample reduces an oxidant or quenches a reactive radical under defined assay conditions. In absorbance-based chemistry methods, activity is usually inferred from the drop between a corrected control signal and a corrected sample signal.
The calculator above combines two common reporting layers. First, it calculates percent inhibition, which is easy to compare within a single assay run. Second, it converts the net response into an equivalent concentration using a standard curve, then normalizes the result to sample mass.
This is helpful because percent inhibition alone does not account for sample amount, dilution, or extraction volume. Two samples can show similar inhibition yet differ greatly in equivalent content per gram. Mass-normalized reporting improves comparison across batches, preparation methods, and matrix types.
Blank correction is also important. A sample may contribute its own color or turbidity, while the reagent system may contribute a baseline signal. Subtracting these effects produces a cleaner response value and reduces overestimation or underestimation.
For best practice, keep standards and samples in the same working range, confirm that the linear model fits your calibration, and document the exact assay label, wavelength, solvent system, and reaction time used during measurement.
Here, it means the measured ability of a sample to reduce the assay signal compared with a corrected control. The calculator reports both inhibition and a calibration-based equivalent value.
It fits absorbance reduction assays that use control, sample, blanks, and a linear standard curve. DPPH and ABTS style workflows are the most direct matches.
Blanks correct background signal. Sample blank removes sample color or haze. Reagent blank removes baseline absorbance from solvent or reagent mixture.
They come from your standard curve. The slope shows response change per unit concentration, and the intercept represents the expected response when concentration is zero.
That usually signals mismatched blanks, absorbance drift, data entry mistakes, or a sample outside the reliable assay range. Recheck raw readings and the calibration model.
Use it whenever the measured solution was diluted before reading. It scales the equivalent concentration back to the original extract basis.
Yes. Keep the calibration consistent, then change the unit labels to match your chosen standard, such as gallic acid equivalents or ascorbic acid equivalents.
No. It is a calculation aid for laboratory interpretation. Formal claims require validated methods, quality controls, and the rules that apply to your field.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.