1. Primäre Kalibriersubstanzen für die
Primary calibration substances to establish metrological traceability in the field of anorganic chemical analytics
Primäre Kalibriersubstanzen für die
metrologische Rückführung in der anorganischen chemischen Analytik
R. Matschat, H. Kipphardt, M. Czerwensky, S. Richter
Bundesanstalt für Materialforschung und -prüfung (BAM)
Fachgruppe I.1 Anorganisch-Chemische Analytik; Referenzmaterialien

2. Inhalt
- Notwendigkeit primärer Kalibriersubstanzen
in der Elementanalytik
- Zertifizierungsstrategien
- Das primäre Kalibriersystem der BAM
- Methoden zur Zertifizierung (Überblick)
- Einige methodische Besonderheiten
- Ergebnisse
* Einige Beispiele
* Überblick
- Zusammenfassung

3. Trends in Elemental Analysis
Increase of speed of analysis,
detection power, selectivity: ==>
extrusion of "classic" (partly "primary")
methods (titrimetry, coulometry,..)
Substitution by atomic spectrometric
methods
Partly in process:
Direct analysis/
solid samples:
spark-OES, XRF; (LIBS);
GD MS, LA-ICP MS
Others:
solution
analysis,
gen. after
digestion/dissolution:
AAS, ICP-OES,
ICP-MS (TXRF)
Verification of trueness:
matrix-CRM
Traceability
of calibration:
necessary:
Matrix-CRM
Primary pure materials
(matrix adapted solutions)
Causal: Signal (analyte and background) are dependent
from entire sample composition - and are in case of solid
sample technique influenced by further properties
of the sample

4. Traceability of
certified values of
Matrix CRMs

5. Metrological Pyramid
SI unit
BAM
certified
Uncertainty
PCRM
Matrix CRM
(secondary) RM
„In house“-RM

6. Certification Strategies
e.g. BCR, BAM (Matrix CRM)
Interlaboratory Cooperation Approach
Elite Group of Methods Approach
e.g. NIST ; BAM (Primary Pure Elements)
Primary Method Approach
e.g. Nuclear RMs (IDMS), Gas RMs (gravimetry)

7. BAM System of Primary Pure Substances
System of certified high purity substances representing
each element of periodic table (except radioactive and
gaseous ones)
Substances are pure elements or pure well defined compounds, if necessary
Material Basis of metrological traceability in the field of
elemental analysis to SI unit (mol, kg) with a well defined
low uncertainty budged
“National Standards for Elemental Analysis in Germany“
by contract with PTB, Germany
Cooperation with PTB and some other National Measurement Institutes

8. System of Primary Pure Substances
Developed by BAM
ANALYTE-CALIBRATION
Materials of type A:
The mass fraction of main component is certified, the uncertainty has to be one order of magnitude lower than for most accurate methods, as IDMS is: <0.01%
Certified by difference method: 100% minus sum
of all (metallic and non-metallic) traces.
Form: small ratio surface/volume:
pellets, wires, spheres, .... no powders
Cleaning procedure included in certificate

9. System of Primary Pure Substances
Developed by BAM
MATRIX ADAPTATION (Metrological Questions) Materials of type B:
All „metallic“ traces are separately certified at a
level of µg/kg
using different methods of highest sensitivity.
Form: no mechanical samle pretreatment:
powders, pellets, spheres, shots.....no wires or bars
Cleaning procedure: not applied

10. System of Primary Pure Elements Developed by BAM
Determination of
metallic traces
HR ICP-MS
continuous nebulization =
main method
ET-, HG-, CV AAS
supplementation, confirmation
metallic
traces in solid sample
LA-ICP-MS
Checking digestion
ICP OES, (INAA)
FI-ICP-MS
(and other special techniques)
decreasing LODs
gases
and non-metals
CGHE; PAA;
nuclear methods;
noble gas-MS
Certified Primary
Pure Element
(Type A)
Calculation of
content and
uncertainty
Scheme of Certification of a Primary Pure Element (Type A)
HR ICP-MS: high sensitivity, selectivity, multielement capability

11. System of Primary Pure Elements Developed by BAM
Some special aspects concerning ICP-mass spectrometry
- Laser - Ablation (Pressed doped metal powder for calibration)
- Flow injection technique (high matrix load up to 10 g/L)
- Preparation of cones with a protective coating:
Spraying of a solution of Silicon into ICP flame
See following explanations
- Using higher resolution for interpreting/avoiding
spectral interferences
See following examples

12. System of Primary Pure Elements Developed by BAM
Some special techniques applied with ICP-mass spectrometry
Laser ablation technique
- direct information about
solid sample
- assessment of losses and of
contamination
- decreasing LODs

13. Sampler Cone of ICP-Mass Spectrometer Element,
Protective Coating ( 30min Silicon Solution, 1000mg/L)
Pictures: Environmental Scanning Electron Microscopy (ESEM)

14. Skimmer Cone of ICP-Mass Spectrometer Element
Protective Coating (30 min Silicon Solution, 1000 mg/L)
Pictures: Environmental Scanning Electron Microscopy (ESEM)

15. without protective coating with protective coating
Protective coating of sampler and skimmer cones of
ICP-mass spectrometer „Element“
Investigations by EDX and by Raman spectroscopy O Ni Si
keV
EDX spectra
without protective coating
with protective coating
Raman spectra
For comparison
quartz glass
crystalline quartz
Protective Coating
amorphous

16. Protective coating of sampler and skimmer cones of
ICP-mass spectrometer „Element“, Analytical performance

17. Protective coating of sampler and skimmer cones of
ICP-mass spectrometer „Element“ - Analytical performance

18. Protective coating of sampler and skimmer cones of
ICP-mass spectrometer „Element“, Analytical performance

19. Using higher resolution for interpreting / avoiding spectral interferences

20. Using higher resolution for interpreting / avoiding spectral interferences

21. Example: Matrix solution Mo 1000 mg/L (Mo ==> 7 isotopes)
Using higher resolution for interpreting / avoiding spectral interferences
Example: Matrix solution Mo 1000 mg/L (Mo ==> 7 isotopes)

22. Currently Certified Mass Fraction:
Primary Copper (A) - BAM-A-Primary-Cu-1
Determined below limits of determinations: mg/kg
Determined above limits of determinations: mg/kg
Determination not relevant; estimated
Currently Certified Mass Fraction: %

23. Elements Developed by BAM
System of Primary Pure
Elements Developed by BAM
Primary Pure Copper (Type A)

25. Currently Certified Mass Fraction:
Primary Iron (A) - BAM-A-Primary-Fe-2 (ECRM 098-1)
Determined below limits of determinations: mg/kg
Determined above limits of determinations: mg/kg
Not yet determined
Determination not relevant; estimated
EURONORM certified before
Currently Certified Mass Fraction: %

26. Primary Iron (A) - BAM-A-Primary-Fe1 and Fe2
Comparison of results of HR ICP MS and ET AAS for both primary iron materials of type A

27. Preliminary Certified Value:
Primary Bismuth (A) - Current State
Determined below limits of determinations: mg/kg
Determined above limits of determinations: mg/kg
Not yet determined
Determination not relevant, estimated
Preliminary Certified Value: %

28. Sample Preparation Procedere
Primary Bismuth (A)
Sample Preparation Procedere
Bi-Material
Etching Procedure:
Sample preparation of 4 subsample was carried out on 3 days.
Etching with HNO3 conc, subb. for 2 min.
Rinsing with H20 in ultrasonic bath 3 times for 30 s
Rinsing with Ethanol
Drying in Laminar flow box
Dissolution Procedure:
Etched Sample is transfered in 100mL volumetric vessel
5mL H2O and 5 mL HNO3 conc., subboiling dest, are added
After complete disolution of the sample
the volumetric vessels were filled with water

29. Priliminary Certified Mass Fraction:
Primary NaCl (A) - BAM-A-Primary-NaCl-1
Determined below limits of determination: 58, mg/kg
Determined above limits of determination: mg/kg
Not yet determined
Determination not relevant; estimated
Priliminary Certified Mass Fraction: %
mass fractions in mg/kg

30. Primary NaCl (A) - BAM-A-Primary-NaCl-1 Thermogravimetry measurements
NaCl before drying:
Mass reduction about 0.2%;
maximum at 385°C
NaCl after drying (500°C, 3h):
No mass reduction is
detectable

31. Survey of Certified BAM Primary Calibration Substances - Current State

32. System of Primary Pure Elements Developed by BAM - National Standards for Elemental Analysis
Conclusion:
The Primary Calibration System of BAM is in progress;
Since 1994 worked on with a variety of different analytical methods
Materials of type A are certified before materials of type B
Co-operation with PTB for transmission of traceability to
laboratories via primary calibration solutions distribu-
ted to manufacturers of commercial calibration solutions.
Solid materials will be distributed to NMIs, only
Co-operation: JEPPIM Project (Joint European Project for
Primary Isotope Measurements): PTB, IRMM, EMPA

33. Thank you for your attention
The BAM System of Primary Pure Substances
R. Matschat, H. Kipphardt, M. Czerwensky, S. Richter
The authors thank:
Dipl.-Min. K. Adam (ESEM)
Dr. K.-W. Brzezinka (Raman sp.)
Dipl.-Ing. Th. Dudzus (PAA)
Dipl.-Chem H.-J. Heinrich (AAS)
Dr. U. Ott ( Noble Gas MS) MPI Mainz
Ing. Ch. Segebade (PAA)
Thank you for your attention