isotopes and impurities in water used for water triple point cells

NMi - the Art of Measurement

1

ISOTOPES AND IMPURITIES IN WATER USED FOR

WATER TRIPLE POINT CELLS

EUROMET project 732

WP3: Water Triple Point Cells


2

WP3: participants and contributors

Participants:• Andrea Peruzzi (NMi VSL)• Steffen Rudtsch (PTB)• Miruna Dobre (SMD)• Davor Zvidic (DZM-LPM)• Aliye Kartal Dogan (UME)

External Contributors:• Harro Meijer (CIO Univ. Groningen)• Detlev Schiel and Reinhard Jaehrling (PTB

Braunschweig)• Ken Hill (NRC Ottawa)


3

Summary

• Water triple point cells manufactured at NMi VSL

Isotopes:• Basic definitions to describe isotopic content of water• Isotopic analysis of water samples• Isotopic corrections• Fractionation effects during fabrication process• Temperature differences between the manufactured cells

before and after applying the isotopic corrections

Impurities:• ICPMS analysis at PTB• Overall Maximum Estimate (OME) method


4

Manufactured Water Triple Point Cells

• 15 water triple point cells manufactured

• Borosilicate vs quartz

• HF vs HNO3

• What is the difference between high-silica glass, fused quartz glass, fused silica glass?

WTP cell ID Type Shell MaterialShell

Cleaning Date of sealing Destination

VSL03T026 3 Borosilicate HF 23-09-2003 Sold

VSL03T028 3 Borosilicate HF 11-09-2003 Sold

VSL03T029 3 Borosilicate HF 03-12-2004 EUROMET-899

VSL03T030 3 Borosilicate HF 26-11-2004 EUROMET-899

VSL03T032 3 Borosilicate HNO3 16-02-2006 EUROMET-899

VSL03T033 2 Borosilicate HF 08-05-2004 Research

VSL03T038 2 Borosilicate HF 03-11-2003 broken

VSL03T039 2 Borosilicate HF 13-06-2003 Research

VSL03T040 3 Quartz HNO3 23-02-2006 broken

VSL06T001 3 Quartz HNO3 30-03-2006 EUROMET-899

VSL06T002 3 Quartz HNO3 23-03-2006 Sold






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Expressing the isotopic composition• Natural water is a mixture of the following 4 isotopologues:

1H216O 1H2

17O 1H218O 2H2

16O

• The triple point temperature of any sample of natural water depends on the relative concentrations of the 4 isotopologues

• Ttp = 273.16 K only for Vienna Standard Mean Ocean Water (VSMOW) :

• In practice, the water contained in a WTPC always deviates from VSMOW.

• The isotopic composition of a sample of natural water is described in terms of its departure from VSMOW (delta-values):

0003799.0/

00200520.0/

00015576.0/

1617

1618

12

VSMOW

VSMOW

VSMOW

OO

OO

HH

VSMOW

VSMOWsample

OO

OOOOO

1618

1618161818

/

//


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Isotopic content of WTPCs

Starting water

Receiver water

Bulb water

u18O = 0.08 permil (k=1)u2H = 0.8 permil (K=1)

• Samples taken at different stages while fabricating the cell

• Isotopic analysis of samples performed by CIO (Univ. Groningen)

• 18O and 2H measured for each sample

O

/(permil) 2H /(permil) 18O /(permil) 2H /(permil) 18O

/(permil) 2H /(permil)

VSL03T026 -6.93 -51.1

VSL03T028 -6.30 -45.5

VSL03T029 -6.15 -43.0 -8.93 -68.8 -8.60 -66.9

VSL03T030 -6.15 -43.0 -8.84 -67.4 -8.51 -65.8

VSL03T032 -5.95 -39.4 -2.93 -19.9

VSL03T033 -3.93 -29.1

VSL03T038 -6.09 -42.0 -4.66 -32.7

VSL03T039 -6.22 -47.1

VSL03T040 -2.38 -11.3 -9.54 -74.7

VSL06T001 -6.36 -45.2 -3.19 -31.4 -8.51 -64.8

VSL06T002 -6.20 -44.9 -9.19 -72.6 -9.21 -70.5

VSL06T003 -4.27 -15.4 -4.71 -22.5 -4.86 -20.5

VSL06T004 -4.27 -15.4 -6.05 -35.0 -6.35 -36.7

VSL06T006 -6.55 -42.9 -8.47 -63.1

VSL06T007 -6.55 -42.9 -8.33 -63.1

Bulb water

WTP cell ID

Starting water Receiver water


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WTPC water and Global Meteoric Water line

For precipitation water: 2H = 8 18O + 10 (GMWL in permil)

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

-10 -8 -6 -4 -2 0 2

18O /(permil)

2H

/(p

erm

il)

Starting w ater

Receiver w ater

Bulb w ater

Hart Scientif ic

Isotech

Curacao

Atlantic Ocean

Brazil

GMWL

VSMOW

GMWL


8

Hart Scientific cell

-6

-4

-2

0

-2 -1 0

18O /(permil)

2H

/(p

erm

il)

Univ. Utah CIO (Univ. Groningen)

Agreement between different labs

(K = 2)

Isotech cell

0

2

46

8

10

1214

16

18

0 1 2 3

18O /(permil)

d2H

/(p

erm

il)

Unknown CIO (Univ. Groningen)

(K = 2)

Isotech cell:CIO analysis:18O = (2.02 0.14) permil2H = (4.9 2.0) permil

Isotech analysis:18O = (1.10 0.21) permil2H = (6.09 6.0) permil

Hart Scientific cell:CIO analysis:18O = (-0.93 0.12) permil2H = (-2.1 2.0) permil

Utah Univ. analysis:18O = (-0.6 0.21) permil2H = (-3.0 6.0) permil


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Applying isotopic corrections

OAOAHATTOOHVSMOWsample

1718217182

KA

KA

KA

O

O

H

257

23641

6628

17

18

2

WTP cell ID

2H bulb water /mmol/mol

18O bulb water /mmol/mol

17O bulb water /mmol/mol

Temperature deviation from

2H / K


18O / K


17O / K

Total Temperature

deviation / K

VSL03T026 -51.1 -6.93 -3.67 -32.09 -4.44 -0.21 -37

VSL03T028 -45.5 -6.30 -3.33 -28.57 -4.04 -0.19 -33

VSL03T029 -66.9 -8.60 -4.55 -42.01 -5.51 -0.26 -48

VSL03T030 -65.8 -8.51 -4.50 -41.32 -5.45 -0.26 -47

VSL03T032

VSL03T033 -29.1 -3.93 -2.08 -18.27 -2.52 -0.12 -21

VSL03T038 -32.7 -4.66 -2.46 -20.54 -2.99 -0.14 -24

VSL03T039 -47.1 -6.22 -3.29 -29.58 -3.99 -0.19 -34

VSL03T040 -74.7 -9.54 -5.05 -46.91 -6.12 -0.29 -53

VSL06T001 -64.8 -8.51 -4.50 -40.69 -5.45 -0.26 -46

VSL06T002 -70.5 -9.21 -4.87 -44.27 -5.90 -0.28 -50

VSL06T003 -20.5 -4.86 -2.57 -12.87 -3.12 -0.15 -16

VSL06T004 -36.7 -6.35 -3.36 -23.05 -4.07 -0.19 -27

VSL06T006 -63.1 -8.47 -4.48 -39.63 -5.43 -0.26 -45

VSL06T007 -63.1 -8.33 -4.41 -39.63 -5.34 -0.25 -45

17O estimated from relation: (Meijer, 1998)528.01817 )1(1 OO


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Isotope fractionation

-60

-50

-40

-30

-20

-10

0

starting water receiver water bulb water

Te

mp

era

ture

de

pre

ss

ion

/ K

VSL03T026 VSL03T028 VSL03T029 VSL03T030 VSL03T032



• Double distillation globally depletes the water (about 20 K)• Degassing enriches the water (only 1-2 K)• UHP water is preferable to filtered tap water

UHP water

Filtered tap water


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Realized triple point temperatures

0

20

40

60

80

100

120

VS

L0

3T

1

VS

L0

3T

2

VS

L0

3T

3

VS

L0

3T

4

VS

L0

3T

5

VS

L0

3T

7

VS

L0

6T

1

VS

L0

6T

2

VS

L0

6T

3

VS

L0

6T

4

VS

L0

6T

5

VS

L0

6T

6

Tem

per

atu

re d

iffer

ence

fro

m o

ld n

atio

nal

ref

eren

ce /m

icro

kelv

in

• Blue: no correction applied • Red: isotopic correction applied

Kduncorrecte 3.37Kcorrected 6.43

(K = 1)


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IMPURITIES (CHEMICAL ANALYSIS)

• ICPMS at NMi VSL, PTB and NRC (to investigate level of agreement between different labs)• Analysis performed on starting, receiver and bulb water (to investigate contaminations from fabrication process)

CellStarting water

Receiver water Bulb water

VSL03T026 VSL-2004VSL03T028 VSL-2004

VSL03T029PTB-2005 NRC-2007

PTB-2005 NRC-2007 NRC-2007

VSL03T030PTB-2005 NRC-2007

PTB-2005 NRC-2007 NRC-2007

VSL03T033 VSL-2004

VSL03T038PTB-2005, VSL-2004 NRC-2007

VSL06T001 PTB-2006VSL06T002 PTB-2006VSL06T003 PTB-2006 PTB-2006VSL06T004 PTB-2006VSL06T006 PTB-2006VSL06T007 PTB-2006


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ICPMS ANALYSIS RESULTS (PTB)

• Concentration (mass fraction in pg/g) for 60 to 70 elemental impurities

• Mass fraction converted into molar fraction (mol/mol)


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OME (Overall Maximum Estimate)

A

c

T ii

MaxOME

• Depending on the cell:

KTK MaxOME 81

• Correction not applied

isotopes and impurities in water used for water triple point cells

Documents

art of measurementwtpc

hbulb water delta18

sample of natural water

bulb water vsl03t0281

water triple point cellsnmi

cio analysis

art of measurementwp3

art of measurementchart16