CCQM-K6 and CCQM-K6.2

MEASURAND : Mass fraction of cholesterol in human serum
2.2 mg/g to 2.3 mg/g (Matrial "A")

Degrees of equivalence Di and expanded uncertainty Ui (95% level of confidence) expressed in mg/g 

CCQM-K6
CCQM-K6.2

MEASURAND : Mass fraction of cholesterol in human serum
Material B : physiological range, ~1.7 mg/g

Degrees of equivalence Di and expanded uncertainty Ui (95% level of confidence) expressed in mg/g (xR = 1.726 mg/g, UR = 0.013 mg/g)

CCQM-K6 and CCQM-K6.2

MEASURAND : Mass fraction of cholesterol in human serum
2.2 mg/g to 2.3 mg/g (Matrial "A")

CCQM-K6
CCQM-K6.2

The full matrix of equivalence is available in Summary Results (summary of the results as a .PDF file).

MEASURAND : Mass fraction of cholesterol in human serum
Material B : physiological range, ~1.7mg/g

   
Lab iDiUi
 / (mg/g)/ (mg/g)
LGC0.0060.017
NARL0.0510.038
NIST0.0090.013
NMi-VSL0.0030.014
NMIJ-0.0080.014
NRCCRM0.0100.017
PTB-0.0210.020

The full matrix of equivalence is available in Summary Results (summary of the results as a .PDF file).

Comparison
Comparison close
CC comparison
Linked comparison
CCQM-K6
Metrology area, Sub-field Chemistry and Biology, Organics
Description Cholesterol in human serum
Time of measurements 2000
Status Approved for equivalence
Final Reports of the comparisons
Measurand Mass fraction: ~2.2 mg/g and ~1.7 mg/g
Transfer device Samples from two frozen human serum pools
Comparison type Key Comparison
Consultative Committee CCQM (Consultative Committee for Amount of Substance)
Conducted by CCQM (Consultative Committee for Amount of Substance)
Comments

Results published on 24 January 2002

Cholesterol in human serum

The CCQM-K6.2 results are linked to the CCQM-K6 results.

Pilot institute NIST
National Institute of Standards and Technology
United States
Contact person M.J. Welch

+1 301 975 3100
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
NIST

National Institute of Standards and Technology, United States, SIM

LGC

Laboratory of the Government Chemist, United Kingdom, EURAMET

NARL

National Analytical Reference Laboratory; became National Measurement Institute, Australia, NMIA in 2004, Australia, APMP

NMIJ AIST

National Metrology Institute of Japan, Japan, APMP

NMi-VSL

Nederlands Meetinstituut - Van Swinden Laboratorium (became VSL in 2009), Netherlands, EURAMET

NRCCRM

National Research Centre for Certified Reference Materials, merged in NIM (National Institute of Metrology) starting 1st January 2006, China, APMP

PTB

Physikalisch-Technische Bundesanstalt, Germany, EURAMET

CCQM-K6 and CCQM-K6.2

MEASURAND : Mass fraction of cholesterol in human serum
2.2 mg/g to 2.3 mg/g (Matrial "A")

 

The key comparison reference value, xR, is calculated as the mean of the participant results excluding NARL and NMi-VSL; xR = 2.200 mg/g.
The expanded uncertainty of the key comparison reference value at a 95% level of confidence is: UR = 0.019 mg/g.

The degree of equivalence of each laboratory with respect to the key comparison reference value is given by a pair of terms: Di = (xi - xR) and Ui, its expanded uncertainty corresponding to a 95% confidence interval, both expressed in mg/g.

 

Linking of CCQM-K6.2 to CCQM-K6

The linking was made via NIST, participating in both comparisons. Regarding the long time laps between the CCQM-K6 and CCQM-K6.2, a consensus value was applied as the key comparison reference value.

 

MEASURAND : Mass fraction of cholesterol in human serum
Material B : physiological range, ~1.7mg/g

The key comparison reference value, xR, is calculated as the mean of the participant results excluding NARL; xR = 1.726 mg/g.
The expanded uncertainty of the key comparison reference value at a 95% level of confidence is: UR = 0.013 mg/g.

The degree of equivalence of each laboratory with respect to the key comparison reference value is given by a pair of terms: Di = (xi - xR) and Ui, its expanded uncertainty corresponding to a 95% confidence interval, both expressed in mg/g.

The degree of equivalence between two laboratories is given by a pair of terms:
Dij = Di - Dj = (xi - xR) - (xj - xR) = (xi - xj) and Uij, its expanded uncertainty corresponding to a 95% confidence interval, both expressed in mg/g.

CCQM-K6 and CCQM-K6.2

MEASURAND : Mass fraction of cholesterol in human serum
2.2 mg/g to 2.3 mg/g (Matrial "A")

xi : result of measurement carried out by laboratory i
ui
: combined standard uncertainty of xi

CCQM-K6

CCQM-K6.2

MEASURAND : Mass fraction of cholesterol in human serum
Material B : physiological range, ~1.7 mg/g

xi : result of measurement carried out by laboratory i
ui
: combined standard uncertainty of xi

 Lab i xi
/ (mg/g)
ui
/ (mg/g)
 LGC 1.732 0.0066
 NARL 1.777 0.0170
 NIST 1.735 0.0033
 NMi-VSL 1.729 0.0045
 NMIJ 1.718 0.0039
 NRCCRM 1.736 0.0062
 PTB 1.705 0.0086