Sørensen formol titration
![Formol titration equation for amino acids in general](/Images/godic/202501/14/Formol_titration-normal4853.png")
![Formol titration equation for proline](/Images/godic/202501/14/Formol_titration-proline4853.png")
The Sørensen formol titration(SFT) invented by S. P. L. Sørensen in 1907 is a titration of an amino acid with potassium hydroxide in the presence of formaldehyde. It is used in the determination of protein content in samples.
If instead of an amino acid an ammonium salt is used the reaction product with formaldehyde is hexamethylenetetramine: