Sørensen formol titration
Encyclopedia
The Sørensen formol titration invented by S. P. L. Sørensen
in 1907 is a titration
of an amino acid
with formaldehyde
in the presence of potassium hydroxide
.
An unknown sample is reacted with a known amount of base
. The remaining base is titrated with acid
to determine the amount of excess base. The difference (total base minus excess) is equal to the amount of amino acid present in the original sample.
S. P. L. Sørensen
Søren Peder Lauritz Sørensen was a Danish chemist, famous for the introduction of the concept of pH, a scale for measuring acidity and basicity. He was born in Havrebjerg, Denmark....
in 1907 is a titration
Titration
Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the...
of an amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
with formaldehyde
Formaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
in the presence of potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
.
- RCH(NH2)COOH + HCHO + KOH → RCH(NHCH2OH)COOK + H2O
An unknown sample is reacted with a known amount of base
Base (chemistry)
For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...
. The remaining base is titrated with acid
Acid-base titration
An acid-base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid or base solution...
to determine the amount of excess base. The difference (total base minus excess) is equal to the amount of amino acid present in the original sample.