AQUA-1: Drinking water Certified Reference Material for trace metals and other constituents

The following tables show those constituents for which certified, reference and information values have been established for this river water certified reference material (CRM).

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 [1] 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 AQUA-1 is 0.9991 g/mL at 21 oC.

Table 1: Certified values for AQUA-1

Element Mass fraction,
μg/kg
Mass concentration,
μg/L
International recognition of
measurement capability (CMC)
aluminium (b,c,d) 54.6 ± 1.6 54.6 ± 1.6 TEW01
antimony (a,b) 0.0683 ± 0.0056 0.0682 ± 0.0056 TEW02
arsenic (b,c) 0.222 ± 0.014 0.222 ± 0.014 TEW03
barium (a,b,c,d) 11.88 ± 0.36 11.87 ± 0.36 TEW04
cadmium (a,b) 0.0044 ± 0.0014 0.0043 ± 0.0014 TEW06
calcium (c,d) 8250 ± 140 8240 ± 140 TEW32
chromium (a,b,c) 0.087 ± 0.008 0.087 ± 0.008 TEW07
cobalt (b,c) 0.0271 ± 0.0028 0.0271 ± 0.0028 TEW08
copper (a,b,c,d) 7.46 ± 0.12 7.46 ± 0.12 TEW09
iron (a,b,c,d) 38.0 ± 1.2 38.0 ± 1.2 TEW10
lead (a,b,c) 1.365 ± 0.034 1.364 ± 0.034 TEW11
magnesium (a,c,d) 1945 ± 40 1944 ± 40 TEW34
manganese (b,c,d) 2.42 ± 0.08 2.42 ± 0.08 TEW12
molybdenum (a,b) 0.189 ± 0.008 0.189 ± 0.008 TEW13
nickel (a,b,c,d) 0.447 ± 0.030 0.447 ± 0.030 TEW14
potassium (b,c,d) 670 ± 10 670 ± 10 TEW33
sodium (b,c,d) 13 730 ± 340 13 710 ± 340 TEW35
strontium (a,b,c,d) 36.05 ± 0.48 36.02 ± 0.48 TEW15
uranium (a,b) 0.006 96 ± 0.000 52 0.006 95 ± 0.000 52 TEW16
vanadium (a,b,c) 0.152 ± 0.008 0.152 ± 0.008 TEW17
zinc (a,b,c) 0.97 ± 0.08 0.97 ± 0.08 TEW18

Table 2: Information values for AQUA-1

Compound Mass fraction,
μg/kg
Mass concentration,
μg/L
inorganic arsenic (e) 0.124 0.124
monomethylarsenic (as As) (e) 0.036 0.036
dimethylarsenic (as As) (e) 0.028 0.028
trimethylarsenic (as As) (e) 0.010 0.010

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 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 volume of 10 mL is recommended.

Storage and sampling

It is recommended that the material be stored at +4 oC temperature. The bottles should be opened only in a clean area with precautions taken against contamination during sampling.

Uncertainty

Included in the overall combined uncertainty estimate (uc) are uncertainties in the batch characterization (u,char), 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 3.

Table 3: Uncertainty components for AQUA-1

Element uc,
μg/kg
uchar,
μg/kg
uhom,
μg/kg
umethod,
μg/kg
aluminium 0.8 0.8 0.0 0.0
antimony 0.0028 0.0028 0.0000 0.0000
arsenic 0.007 0.007 0.000 0.000
barium 0.18 0.18 0.00 0.00
cadmium 0.0007 0.0007 0.0000 0.0000
calcium 70 70 0 0
chromium 0.004 0.004 0.002 0.000
cobalt 0.0014 0.0014 0.0000 0.0000
copper 0.06 0.06 0.00 0.00
iron 0.6 0.6 0.0 0.0
lead 0.017 0.015 0.007 0.000
magnesium 20 18 0 9
manganese 0.04 0.03 0.00 0.02
molybdenum 0.004 0.004 0.000 0.000
nickel 0.015 0.007 0.004 0.013
potassium 5 5 0 0
sodium 170 170 0 0
strontium 0.24 0.24 0.00 0.00
uranium 0.000 26 0.000 22 0.000 14 0.000 00
vanadium 0.004 0.004 0.000 0.000
zinc 0.04 0.02 0.00 0.03

Date of issue: January 2017
Date of expiry: January 2022

Date modified: