DUWF-1: Durum Wheat Flour Reference Material for Trace Metals and other Constituents

DUWF‑1 is a Reference Material prepared from food grade durum wheat flour. Reference and information quantity values are provided in the following tables for trace metals and other constituents. Reference values are equally weighted means of results from at least two analytical methods and/or laboratories. Uncertainties are expressed as a 95% confidence interval. All values are expressed on a dry-mass basis.

Table 1: Reference values for DUWF‑1

Element Mass fraction, mg/kg
Aluminium 11.7 ± 4.7
Barium 2.11 ± 0.47
Cadmium 0.11 ± 0.05
Calcium 278 ± 26
Chromium 0.023 ± 0.009
Cobalt 0.008 ± 0.004
Copper 4.30 ± 0.69
Iron 41.5 ± 4.0
Lead 0.023 ± 0.006
Magnesium 1070 ± 80
Manganese 16.0 ± 1.0
Molybdenum 0.70 ± 0.12
Nickel 0.17 ± 0.08
Phosphorus 2900 ± 220
Potassium 3180 ± 140
Rubidium 2.0 ± 0.4
Sodium 16.0 ± 6.1
Sulfur 1930 ± 280
Strontium 1.19 ± 0.09
Vanadium 0.021 ± 0.006
Zinc 22.2 ± 1.7

Table 2: Information values for trace elements in DUWF‑1

Element Mass fraction, mg/kg
Arsenic 0.03
Bromine 6.6
Chlorine 680
Fluorine 0.1
Iodine 0.006
Nitrogen 27 000
Titanium 5

Table 2 (continued): Information values for DUWF‑1

Quantity Value Unit
Ash 1.364 g/(100 g), %
Protein 15.48 g/(100 g), %
Carbohydrate 80.34 g/(100 g), %
Total dietary fibre 4.61 g/(100 g), %
Energy content 408.6 kcal/(100 g)
Energy content 1709 kJ/(100 g)

The protein concentration was calculated from the nitrogen values using a conversion factor of 6.25; subsequent calculations of carbohydrates and calories were also based on these protein concentrations. The value for energy content is the mean of the individual caloric calculations. The mean proximate values were used for calculation, with caloric equivalents of 9, 4, and 4 for fat, protein, and carbohydrate, respectively.

Intended use

This Reference Material (RM) is intended for use in evaluating analytical methods and instruments used for the determination of major, minor, and trace constituent elements in flour and other similar food, agricultural, and biological materials. A minimum sample mass of 500 mg is recommended.

This material is intended for laboratory use, not for human consumption.

Uncertainty

Original uncertainty estimates for RM 8436 were verified at NRC and were retained in this report. As stated in the RM 8436 report [1], uncertainties are imprecision estimates expressed as a 95% confidence interval, based on a sample mass of at least 500 mg. These uncertainties, based on between-method and between-laboratory, between-unit and within-unit estimates of variances, include measures of analytical method and laboratory imprecisions and biases and material inhomogeneity.

DUWF-1
Date of Issue: September 2015
Date of Expiry: September 2025
Revised: March 2016 (editorial update)

Date modified: