Entitic amount-of-substance (entitic am.s.) - Dynamic NPU Manual

Entitic amount-of-substance (entitic am.s.)


Entitic am.s.

Definition in words

Amount-of-substance of component B divided by the number of entities

Alternative expression: Amount-of-sustance of component B per entity

Note: Entity is a particle, molecule or a cell.

Definition by equation

Systematic terms

Entitic amount-of-substance of component B per entity in a system

Result type

Rational scale
  • Value sets are positive numerical values
  • Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞


amol, fmol, pmol, nmol etc.

Note: The correct unit is e.g. “amol/1” but “1” is omitted.

Special rule(s) in the NPU syntax

The entity is the system 1 in the NPU syntax.


Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p.

Laboratory field


Clinical Chemistry


Example 1
Generic abbreviated
NPU17007 Rtcs(B)—Haemoglobin(Fe); entitic am.s. = ? fmol
Full result NPU17007 Reticulocytes(Blood)—Haemoglobin(Fe); entitic amount-of-substance = 2  fmol per Reticulocyte
Abbreviated result NPU17007 Rtcs(B)—Haemoglobin(Fe); entitic am.s. = 2 fmol
Written expression The entitic amount-of-substance of Haemoglobin(Fe) per Reticulocyte in Mr. Smith’s blood is [2.0] fmol.


“Fe” is the IUPAC symbol for iron atom.
Example 2
Generic abbreviated
NPU02320 Ercs(B)—Haemoglobin(Fe); entitic am.s. = ? fmol
Full result NPU02320 Erythrocytes(Blood)—Haemoglobin(Fe); entitic amount-of-substance = 1.8 fmol per Erythocyte
Abbreviated result NPU02320 Ercs(B)—Haemoglobin(Fe); entitic am.s. = 1.8 fmol
Written expression The entitic amount-of-substance of Haemoglobin(Fe) per Erythrocyte in Mr. Smith’s blood is [1.8] amol.

The popular name and abbreviation for this examination is “mean corpuscular hemoglobin” and “MCH”

“Fe” is the IUPAC symbol for iron atom.

Thrombosis and Haemostasis

Example 3
Generic abbreviated
NPU02384 Trcs(B)—Histidine-rich glycoprotein; entitic am.s. = ? amol
Full result NPU02384 Thrombocytes(Blood)—Histidine-rich glycoprotein; entitic amount-of-substance = 20 attomol per Thrombocyte
Abbreviated result NPU02384 Trcs(B)—Histidine-rich glycoprotein; entitic am.s. = 20 amol
Written expression The entitic amount-of-substance of Histidine-rich glycoprotein per Thrombocyte in Mr. Smith’s blood is [20] amol.


NPU database, https://www.ifcc.org/ifcc-scientific-division/sd-committees/c-npu/npusearch/ and http://www.labterm.dk/default.aspx
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Entitic amount-of-substance


  • Dybkaer R. Concept system on ‘quantity’: formation and terminology. Accredit Qual Assur. 2013;18(3):253-60.
  • Dybkaer R. ISO terminological analysis of the VIM3 concepts ‘quantity’ and ‘kind-of-quantity’. Metrologia. 2010;47(3):127-34.
Date Term Note
1996-01-01 Entitic amount-of-substance Term established