1 Reply Latest reply on Nov 22, 2011 5:08 PM by Maysoon Al-Hafez

    How do we choose the standard for calibration curves?

    Maysoon Al-Hafez

      For example, if I waned to make a calibration curve for calculating total phenols by Folin assay, I should use Gallic acid as a standard. that's what most papers say, but why to use Gallic acid not any other phenol??? and in general, on what basics do we say that a substance is a standard?

      please, I want answers with references...ASAP.

        • Re: How do we choose the standard for calibration curves?
          Maysoon Al-Hafez

          Hello everyone:

          I found the answer for my own question....

          The exact reasons of choosing Gallic acid as a standard are:

            -Partly for historical reasons,

            -Inexpensive,

            -Soluble in water,

            -Recrystallized easily from water,

            -Readily dried, and

            -Stable in the dry form.

          for these reasons Gallic acid is #1, but catechin can also be used as standard in Folin-Ciocalteu assay.

           

          So I think that there isn't a general rule but every standard has different reasons for choosing it.

          Hope you find it useful......