DORM-4: Fish protein certified reference material for trace metals

The following table shows those elements for which certified values have been established for this reference material. Certified values are based on results from data generated at NRC. The expanded uncertainty (UCRM) in the certified value is equal to U = kuc where uc is the combined standard uncertainty calculated according to the JCGM Guide and k is the coverage factor. It is intended that UCRM encompasses every aspect that reasonably contributes to the uncertainty of the measurement. A coverage factor of 2 was applied for all elements. The table below lists certified values for DORM‑4 expressed on a dry mass basis.

Table 1: Certified quantity values

Element Mass fraction,
(mg/kg)
Arsenic (b,d,f) 6.87 ± 0.44
Cadmium (a,d) 0.299 ± 0.018
Calcium (d,e) 2360 ± 140
Chromium (a,d,e) 1.87 ± 0.18
Copper (a,d,e) 15.7 ± 0.46
Iron (a,d) 343 ± 20
Lead (a,b,d) 0.404 ± 0.062
Magnesium (d,e) 910 ± 80
Manganese (b,d,e) 3.17 ± 0.26
Mercury (a,c,g) 0.412 ± 0.036
Nickel (a) 1.34 ± 0.14
Potassium (d,e) 15 500 ± 1000
Selenium (a,d,f) 3.45 ± 0.40
Silver (a,d) 0.0252 ± 0.0050
Strontium (d,e) 10.1 ± 0.8
Vanadium (d,e) 1.57 ± 0.14
Zinc (a,d) 51.6 ± 2.8
Substance Mass fraction,
(mg/kg)
Arsenobetaine (as As) (h,i) 3.95 ± 0.36
Methylmercury (As Hg) (j,k) 0.355 ± 0.028

Table 2: Reference Values

Element Mass fraction,
(mg/kg)
Aluminium (b,d,e) 1280 ± 340 Footnote 1
Sodium (d,e) 14 000 ± 2400
Tin (a,d) 0.061 ± 0.018

Footnotes

Footnote 1

Note: The mass fraction of aluminium is obtained without the use of hydrofluroic acid.

Return to footnote 1 referrer

Table 3: Information Values

Element Mass fraction,
(mg/kg)
Cobalt (d) 0.25
Lithium (d) 1.21
Molybdenum (d) 0.29
Phosphorus (d) 8 000
Uranium (d) 0.050
Substance Mass fraction,
(mg/kg) (as Sn)
Monobutyltin (j) < 0.05
Dibutyltin (j) < 0.005
Tributyltin (j) < 0.005

Coding

The coding refers only to the instrumental method used for quantitation.

  • a – Isotope dilution inductively-coupled plasma mass spectrometry (ID‑ICP‑MS)
  • b – Standard addition inductively-coupled plasma mass spectrometry (ICP‑MS)
  • c – Inductively-coupled plasma mass spectrometry (ICP‑MS)
  • d - Inductively coupled plasma atomic emission spectroscopy (ICP‑AES)
  • e – Standard addition inductively-coupled plasma atomic emission spectroscopy (ICP‑AES)
  • f – Hydride generation graphite furnace atomic absorption spectroscopy
  • g – Cold-vapour atomic absorption spectroscopy (CV‑AAS)
  • h – Standard addition liquid chromatography ICP‑MS (LC‑ICP‑MS)
  • i - Isotope dilution liquid chromatography Orbitrap mass spectrometry
  • j - Isotope dilution gas chromatography ICP‑MS (ID‑GC‑ICP‑MS)
  • k - Isotope dilution gas chromatography mass spectrometry (ID‑GC‑MS)

Uncertainty

Included in the overall combined uncertainty estimate (uc) are uncertainties in the batch characterization (uchar), uncertainties related to possible between-bottle variation (uhom), and uncertainties related to inconsistency between the various measurement methods (umethod). Expressed as standard uncertainties, these components are listed below:

Table 4: Uncertainty Components

Element uc,
mg/kg
uchar,
mg/kg
uhom,
mg/kg
umethod,
mg/kg
Arsenic 0.22 0.11 0.19 0.00
Cadmium 0.009 0.005 0.007 0.000
Calcium 70 30 60 0
Chromium 0.09 0.05 0.08 0.00
Copper 0.23 0.07 0.22 0.00
Iron 10 5 9 0
Lead 0.031 0.007 0.030 0.000
Magnesium 40 40 20 0
Manganese 0.13 0.09 0.10 0.00
Mercury 0.018 0.009 0.016 0.000
Nickel 0.07 0.05 0.05 0.00
Potassium 500 300 400 0
Selenium 0.20 0.10 0.17 0.00
Silver 0.0025 0.0014 0.0020 0.0004
Strontium 0.4 0.3 0.3 0.0
Vanadium 0.07 0.07 0.01 0.0
Zinc 1.4 0.8 1.1 0.0
Substance uc,
mg/kg
uchar,
mg/kg
uhom,
mg/kg
umethod,
mg/kg
Arsenobetaine (as As) 0.18 0.17 0.05 0.00
Methylmercury (as Hg) 0.014 0.007 0.012 0.000
Element uc,
mg/kg
uchar,
mg/kg
uhom,
mg/kg
umethod,
mg/kg
Aluminium 170 40 50 160
Sodium 1200 200 200 1200
Tin 0.009 0.003 0.004 0.007

Intended use

This reference material is primarily intended for use in the calibration of procedures and the development of methods for the determination of trace metals in marine fauna and materials of similar matrix.

Date of issue: June 2012
Revised Date: February 2015
Date of expiry: June 2022