SLRS-6: River Water Certified Reference Material for Trace Metals and other Constituents

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. A coverage factor of two (2) was applied for all elements. It is intended that UCRM accounts for every aspect that reasonably contributes to the uncertainty of the measurement. The density of SLRS-6 is 0.9985 g/mL at 21 °C.

Table 1: Certified quantity values for SLRS-6

Element Mass fraction
μg/kg
Mass concentration
μg/L
Aluminium (b,c,d) 33.9 ± 2.2 33.8 ± 2.2
Antimony (a,b) 0.3377± 0.0058 0.3372± 0.0058
Arsenic (b,c,e) 0.57 ± 0.08 0.57 ± 0.08
Barium (a,b,c,d) 14.30 ± 0.48 14.28 ± 0.48
Cadmium (a,b) 0.0063 ± 0.0014 0.0063 ± 0.0014
Calcium (c,d) 8770 ± 200 8760 ± 200
Chromium (a,b,d) 0.252 ± 0.012 0.252 ± 0.012
Copper (a,b,c,d) 24.0 ± 1.8 23.9 ± 1.8
Iron (a,b,c,d) 84.5 ± 3.6 84.3 ± 3.6
Lead (a,b) 0.170 ± 0.026 0.170 ± 0.026
Magnesium (c,d) 2137 ± 58 2133 ± 58
Manganese (b,c,d) 2.12 ± 0.10 2.12 ± 0.10
Molybdenum (a,b,d) 0.215 ± 0.018 0.215 ± 0.018
Nickel (a,b,d) 0.617 ± 0.022 0.616 ± 0.022
Potassium (c,d) 652 ± 54 651 ± 54
Sodium (c,d) 2770 ± 220 2760 ± 220
Strontium (a,b,c,d) 40.72 ± 0.32 40.66 ± 0.32
Uranium (a,b) 0.0699 ± 0.0034 0.0698 ± 0.0034
Vanadium (b,d) 0.352 ± 0.006 0.351 ± 0.006
Zinc (a,b,c,d) 1.76 ± 0.12 1.76 ± 0.12

Table 2: Reference values for SLRS-6

Element Mass fraction
μg/kg
Mass concentration
μg/L
Beryllium (b) 0.0066 ± 0.0022 0.0066 ± 0.0022
Cobalt (b) 0.053 ± 0.012 0.053 ± 0.012

Table 3: Information Values for SLRS-6

Compound Mass fraction
μg/kg
Mass concentration
μg/L
inorganic arsenic (f) 0.36 0.36
monomethylarsenic (as As) (f) 0.07 0.07
dimethylarsenic (as As) (f) 0.07 0.07
trimethylarsenic (as As) (f) 0.021 0.021

Coding

The coding refers to the instrumental method of analyte determination.

  • a – Isotope dilution inductively-coupled plasma mass spectrometry (ID-ICP-MS)
  • b – Standard addition inductively-coupled plasma mass spectrometry (SA-ICP-MS)
  • c – Inductively-coupled plasma mass spectrometry (ICP-MS)
  • d – Standard addition inductively-coupled plasma atomic emission spectroscopy (SA-ICP-AES)
  • e – Hydride generation SA-ICP-MS
  • f – Hydride generation cryo-trapping ICP-MS

Intended use

This certified reference material is primarily intended for use in the calibration of procedures and the development of methods used for the analysis of water for trace metals. A minimum sample mass of 10mL is recommended.

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 in Table 4.

Table 4: Uncertainty Components for SLRS-6

Element Uc
μg/kg
uchar
μg/kg
uhom
μg/kg
umethod
μg/kg
Aluminium 1.1 1.0 0.0 0.5
Antimony 0.0029 0.0026 0.0013 0.0000
Arsenic 0.04 0.04 0.00 0.00
Barium 0.24 0.21 0.11 0.00
Cadmium 0.0007 0.0007 0.0001 0.000
Calcium 100 90 40 0
Chromium 0.006 0.006 0.000 0.000
Copper 0.9 0.9 0.2 0.0
Iron 1.8 1.7 0.5 0.0
Lead 0.013 0.013 0.000 0.000
Magnesium 29 17 23 0
Manganese 0.05 0.05 0.00 0.00
Molybdenum 0.009 0.008 0.005 0.000
Nickel 0.011 0.008 0.008 0.000
Potassium 27 12 24 0
Sodium 110 100 40 0
Strontium 0.16 0.14 0.08 0.00
Uranium 0.0017 0.0017 0.0000 0.0000
vanadium 0.003 0.003 0.000 0.000
Zinc 0.06 0.05 0.03 0.00

Table 4 (continued): Uncertainty components for SLRS-6

Element Uc
μg/kg
uchar
μg/kg
uhom
μg/kg
umethod
μg/kg
Beryllium 0.0011 0.0011 0.0003 0.0000
Cobalt 0.006 0.006 0.000 0.000

Date of Issue: September 30 2015
Date of Expiry: September 30 2020
Revised: March 2016 (concentrations in Table 1 corrected and editorial update)); January 2017 (inorganic arsenic, monomethylarsenic, dimethylarsenic, and trimethylarsenic added)

Date modified: