1. 22nd Meeting of the CCU BIPM, Sèvres, France
CCQM Actions Taken Since the 20th Meeting of the CCU Relevant to the Adoption of the Revised SI
22nd Meeting of the CCU BIPM, Sèvres, France
Willie E. May
CCQM Chair
15-16 June 2016

2. Consultative Committee for Metrology in Chemistry and Biology (CCQM)
Established by the CIPM in 1993
40 Official member (28) and observer (12) organizations
10 Standing Working Groups and 3 ad hoc Working Groups
8 Standing Technical Working Groups, most meet twice a year
Attended by ~ 230+ experts from NMI’s and other expert institutes
Yearly meetings of CCQM plenary, attended by ~70 representatives from Member and Observer Institutes, stakeholder organizations and Guests
Figures of Merit
Over 6000 CMCs are currently published in 840 different analytes
( 3050 different analyte‐matrix combinations)
Number of analyte matrix combinations increasing at a rate of about 250 per year.
Over 380 comparisons (204 Key and 176 Pilot) have been conducted 2 2

3. CCQM –Terms of Reference
The CCQM is responsible for developing, improving and documenting the equivalence of national reference systems for chemical and biological measurements. It advises the CIPM on matters related to chemical and biological measurements including advice on the BIPM scientific program activities.
The responsibilities of the CCQM are:
to establish global comparability of measurements through promoting traceability to the SI, and where traceability to the SI is not yet feasible, to other internationally agreed references;
to contribute to the establishment of a globally recognized system of national measurement standards, methods and facilities for chemical and biological measurements;
to contribute to the implementation and maintenance of the CIPM MRA with respect to chemical and biological measurements;
to review and advise the CIPM on the uncertainties of the BIPM's calibration and measurements services as published on the BIPM website;
to act as a forum for the exchange of information about the research and measurement service delivery programs and other technical activities of the CC members and observers, thereby creating new opportunities for collaboration.

4. CCQM Organizational Structure
President: W. May, CIPM, NIST
Executive Secretary: R. Wielgosz, BIPM
10 permanent working groups and chairs
Organic Analysis (OAWG) L. Mackay NMIA
Gas Analysis (GAWG) J.S. Kim KRISS
Inorganic Analysis (IAWG) M. Sargent LGC
Electrochemical Analysis (EAWG) M. Mariassy SMU
Cells (CWG) A. Plant NIST
Nucleic Acids (NAWG) H. Parkes LGC
Protein Analysis (PAWG) S-R. Park KRISS
Surface Analysis (SAWG) W. Unger BAM
Key Comparison and CMC Quality (KCWG) W.M.(Della) Sin GLHK
Strategic Planning (SPWG) W. May NIST
3 current ad hoc groups:
ad hoc working group on the mole B. Güttler PTB
ad hoc steering group on microbial
measurements (MBSG) J. Morrow NIST
ad hoc working group on improvement of
CMC formulation and review R. Kaarls CCQM Immed.Past Pres.

5. CCQM ad hoc WG on Mole Responsibilities
draft a "mise‐en‐pratique" for the realization of the mole;
create awareness with respect to a possible redefinition of the mole .

6. More on this later in CCU Meeting

7. “Chemistry and the International System of Weights and Measures”
Symposium at American Chemical Society (ACS) National Meeting
Boston, MA, August 19, 2015
Introduction to symposium: Introduction to the International System of Weights and Measures W.E. May (NIST)
Session I: The Consultative Committee on Metrology in Chemistry and Biology: Who We are, What We Do, and Why You Should Care
The CCQM, What It Does, What It Has Achieved and Why It is Important to You R. Kaarls, CCQM Pres. Emeritus
CCQM Activities and Impact in Healthcare W. May, NIST
CCQM Activities and Impact in Environment and Climate R. Wielgosz, BIPM
CCQM Activities and Impact in Food Safety and Nutrition S. Wise, NIST
Session II: Redefinition of the International System of Units
Linking the International System of Units to Fundamental Constants J. Ullrich, PTB
Units and Accurate Measurements in Chemistry R. Wielgosz, BIPM
Progress in the redefinition of the Mole B. Guttler, PTB
Redefinition of the Kilogram R. Davis, BIPM
In Addition, The CCQM

8. Mise en pratique of the (new) definition of the mole
Richard Davis
member, CCQM AHWG on the mole
CCU June 2016

9. Mission statement
CCU June 2016

10. mise en pratique (quick review)
no of X entities
Si XRCD
(unique)
gravimetry
(most widely used)
gas analysis
electrolyis
amount of X
Avogadro constant
CCU June 2016

11. n equals volume, VS , divided by molar volume, NAa(28Si)3/8.
2. Realization of the definition of the mole with the smallest uncertainty
Silicon XRCD
determine a
determine VS
n equals volume, VS , divided by molar volume, NAa(28Si)3/8.
ur  2  10-8
CCU June 2016

12. 3. Common methods for the realization and dissemination of the mole
Gravimetric preparation
n equals total mass of X, w(X)m,
divided by molar mass of X, Ar(X)Mu.
ur > 10-6 is usual
CCU June 2016

13. 3. Common methods for the realization and dissemination of the mole
Use of the gas law
NOAA. relative mole fraction of CO2 in air; 1997-present
R (=NAk) has a fixed value
CCU June 2016

14. 3. Common methods for the realization and dissemination of the mole
Electrolysis
Bower&Davis 1980; last electro-chemical measurement of F
F (=NAe) has a fixed value
CCU June 2016

15. 5. Continuity with previous definition
The molar mass constant Mu no longer has a fixed value
Recall slide 5:
The mise en pratique shows the quantity relation
and states that Mu = 10-3 kg mol-1
with ur  10-9 (based on CODATA 2010; to be updated).
CCU June 2016

16. Next meeting of AHWG on the mole: TBD when needed.
(Next meeting of CCQM & WGs:
April 2017.)
CCU June 2016

17. Thank you for your interest
Discussion?