GLUT-1: Wheat Gluten Reference Material for Trace Metals and other Constituents

GLUT‑1 is a Reference Material prepared from food grade wheat gluten. 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 GLUT‑1

Element Mass fraction, mg/kg
Barium 1.53 ± 0.26
Cadmium 0.064 ± 0.022
Calcium 369 ± 35
Chromium 0.053 ± 0.013
Cobalt 0.010 ± 0.006
Copper 5.94 ± 0.72
Iron 54.3 ± 6.8
Magnesium 510 ± 47
Manganese 14.3 ± 0.8
Molybdenum 0.76 ± 0.09
Nickel 0.13 ± 0.04
Lead 0.10 ± 0.05
Phosphorus 2 190 ± 150
Potassium 472 ± 61
Selenium 2.58 ± 0.19
Sodium 1 420 ± 110
Sulfur 8 450 ± 850
Strontium 1.71 ± 0.26
Zinc 53.8 ± 3.7

Table 2: Information values for GLUT‑1

Element Mass fraction, mg/kg  
Aluminium 10.8
Antimony 0.01
Arsenic 0.02
Boron 0.4
Bromine 3.6
Fluorine 0.43
Chlorine 3 600
Iodine 0.06
Rubidium 0.4
Nitrogen 146 000
Titanium 2
Vanadium 0.04

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

Quantity Value Unit
Ash 0.937 g/(100 g), %
Protein 82.7 g/(100 g), %
Carbohydrate 11.1 g/(100 g), %
Fat 5.2 g/(100 g), %
Energy content 422.2 kcal/(100 g)
Energy content 1766 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 8418 were verified at NRC and were retained in this report. As stated in the RM 8418 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.

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

Date modified: