Substance concentration (subst.c.) - Dynamic NPU Manual

Substance concentration (subst.c.)


Amount-of-substance concentration, molar concentration



Definition in words

Amount-of-substance of component B divided by volume of system 1

Definition by equation

Systematic terms

Substance concentration of component B in system 1

Result type

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


fmol/L, pmol/L, nmol/L, μmol/L, mmol/L, mol/L, etc.

Non-recommended term

Molarity, molecular concentration


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. doi:10.1039/9781782622451.

Laboratory field



Example 1
Generic abbreviated
NPU08941 P—Eosinophil peroxidase; subst.c. = ? nmol/L
Full result NPU08941 Plasma—Eosinophil peroxidase; substance concentration = 13 nanomol per litre
Abbreviated result NPU08941 P—Eosinophil peroxidase; subst.c. = 13 nmol/L
Written expression The substance concentration of Eosinophil peroxidase in Mr. Smith’s plasma is [13] nmol/L.

Clinical Chemistry

Example 2
Generic abbreviated
NPU01443 P—Calcium(II); subst.c. = ? mmol/L
Full result NPU01443 Plasma—Calcium(II); substance concentration = 2.21 millimol per litre
Abbreviated result NPU01443 P—Calcium(II); subst.c. = 2.21 mmol/L
Written expression The substance concentration of Calcium(II) in Mr. Smith’s plasma is [2.21] mmol/L.

Notes The roman numeral “II” indicates the oxidation number of calcium. It represents calcium in ionic and chelate forms.

Clinical Immunology and Biobanking

Example 3
Generic abbreviated
NPU01720 P—Complement C1 esterase inhibitor; subst.c.(proc.) = ? µmol/L
Full result NPU01720 Plasma—Complement C1 esterase inhibitor; substacnce concentration(procedure) = 4.0 micromol per litre
Abbreviated result NPU01720 P—Complement C1 esterase inhibitor; subst.c.(proc.) = 4.0 µmol/L
Written expression The substance concentration of Complement C1 esterase inhibitor in Mr. Smith’s plasma is [4.0] µmol/L.

Clinical Pharmacology

Example 4
Generic abbreviated
NPU01886 P—Digoxin; subst.c. = ? nmol/L
Full result NPU01886 Plasma—Digoxin; substance concentration = 3.0 nanomol per litre
Abbreviated result NPU01886 P—Digoxin; subst.c. = 3.0 nmol/L
Written expression The substance concentration of Digoxin in Mr. Smith’s plasma is [3.0] nmol/L.

Clinical Toxicology

Example 5
Generic abbreviated
NPU29964 U—6-O-Monoacetylmorphine; subst.c. = ? nmol/L
Full result NPU29964 Urine—6-O-Monoacetylmorphine; substance concentration = 0.5 nanomol per litre
Abbreviated result NPU29964 U—6-O-Monoacetylmorphine; subst.c. = 0.5 nmol/L
Written expression The substance concentration of 6-O-Monoacetylmorphine in Mr. Smith’s urine is [0.5] nmol/L.

Molecular Biology and Genetics

Example 6
Generic abbreviated
NPU58306 B—2-Decenoyl carnitine; subst.c. = ? µmol/L
Full result NPU58306 Blood—2-Decenoyl carnitine; substance concentration = 15 micromol per litre
Abbreviated result NPU58306 B—2-Decenoyl carnitine; subst.c. = 15 µmol/L
Written expression The substance concentration of 2-Decenoyl carnitine in Mr. Smith’s blood is [15] µmol/L.

Reproduction and Fertility

Example 7
Generic abbreviated
NPU02097 SemP—Fructose; subst.c. = ? mmol/L
Full result NPU02097 Seminal Plasma—Fructose; substance concentration = 15 millimol per litre
Abbreviated result NPU02097 SemP—Fructose; subst.c. = 15 mmol/L
Written expression The substance concentration of Fructose in Mr. Smith’s seminal plasma is [15] mmol/L.

Thrombosis and Haemostasis

Example 8
Generic abbreviated
NPU02050 P—Fibrinogen; subst.c.(coag.; proc.) = ? µmol/L
Full result NPU02050 Plasma—Fibrinogen; substance concentration(coagulation; procedure.) = 25 micromol per litre
Abbreviated result NPU02050 P—Fibrinogen; subst.c.(coag.; proc.) = 25 µmol/L
Written expression The substance concentration of Fibrinogen in Mr. Smith’s plasma is [25] µmol/L. The measurement is performed according to a coagulation procedure defined by the laboratory.


   NPU database, and
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Substance concentration


  • 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 Substance concentration Term established