Kendrick Mass

Kendrick Mass (wikipedia)

• Kendrick mass: Defined as setting the mass of a molecular fragment to an Da (dalton).
• Dalton: Da symbol, unit of mass, defined as $\frac{1}{12}$ of the mass of carbon-12.

Definition

The mass of $CH_2$ is defined as 14 Da, rather than the IUPAC value of 14.01565 Da. The conversion is done as: $Kendrick mass = {IUPAC} {mass} \times \frac{14.00000}{14.01565}$

Kendrick mass defect

The exact Kendrick mass subtracted from the nominal Kendrick mass: $\text{Kendrick mass defect} = \text{nominal Kendrick mass - Kendrick mass}$ But due to rounding errors has become: $\text{Kendrick mass defect} = \text{nominal mass} - \text{Kendrick exact mass}$