Calculate molar concentration, absorbance, extinction coefficient or optical path using Beer–Lambert law; use linear-fit coefficients or blank-corrected absorbance ratios for the separate calibration and preparation modes.

Use a method-validated wavelength, blank, matrix and linear range. Beer–Lambert assumes proportional response for the absorbing species; calibration and dilution assumptions are shown with the result.

Default 1 cm is a common cuvette path. Confirm the actual path.

Result unit

Concentration from Absorbance Formula

The following formula is used to calculate a concentration from absorbance.

C = A / (L × e)
  • Where A is the absorbance
  • L is the path length
  • e is the extinction coefficient

To calculate the concentration from absorbance, divide the absorbance by the product of the path length and extinction coefficient.

Concentration Definition

Molar concentration is the amount of a specified substance per solution volume, commonly expressed in mol/L. Use a species- and wavelength-specific molar coefficient and a method-validated blank, matrix and linear range.

Concentration from Absorbance Example

How to calculate concentration from absorbance?

  1. First, determine the absorbance.

    Calculate the absorbance.

  2. Next, determine the path length.

    Use the optical path length through the sample and its matching unit.

  3. Next, determine the extinction coefficient.

    Use a verified molar coefficient for the species, wavelength and conditions.

  4. Finally, calculate the concentration.

    Calculate the concentration using the equation above.

FAQ

What is a concentration?

Here, concentration means moles of the specified substance per solution volume.