Reference Material Institute for Clinical Chemistry Standards (ReCCS)
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Certified Reference Material for Blood Gases
JCCRM 621-4
Handling Instructions
■Properties and Intended Use
This Certified Reference Material (CRM) for Blood Gases is intended for use in verifying the accuracy of
blood gas (pH, pCO2, pO2) analysers in clinical testing. It is prepared from bovine hemoglobin.
The differences in the oxygen buffering capacities between human whole blood and bovine hemoglobin
have been corrected by the mean differences between these two detected by almost all pO2 instruments.
Therefore using the certified values, you can obtain virtually the same values as you would with human
whole blood.
Note: This CRM cannot be used for blood gas analysers not capable of measuring hemolysate.
■Instruction for Use
This CRM is supplied in an air-tight glass ampoule. Measurements of this material must be taken after
completely equilibrating gases in the ampoule at 37°C (or at 30°C).
Set the water bath temperature at 37°C (or 30°C) and follow the instructions below .
Constant Temperature
Water Bath
37°C ± 0.5°C
(or 30°C ± 0.5°C)
Place ampoule in water
bath and let stand for
about 15 minutes
①Position the ampoule on
its side and shake it
horizontally (about 30
times / 10 seconds)
②Return ampoule to water
bath and stir it in circular
motion for about 10
seconds. Let stand for
about 1 minute
Repeat step ① Repeat step ②
Tap ampoule with
finger tip to allow
content to collect at
the bottom.
Open ampoule and
take measurement
within 30 seconds of
opening.
Reference Material Institute for Clinical Chemistry Standards (ReCCS)
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■Caution
 This CRM is supplied in a glass ampoule. Applying excessive force to the ampoule can result in
breaking the ampoule. Exercise careful caution and wear protective gloves to avoid severe injury
in case of breakage.
 Although this CRM is prepared from hemoglobin of inspected healthy animals which passed
quarantine inspections, exercise caution by treating as if it were human blood and infection.
 In-Vitro Use Only
■Storage Temperature and Expiration Date
This CRM is shipped frozen (packed with dry ice). Store the product in a deep freezer or a refrigerator
upon receipt. Shelf life is shown below according to the specified storage temperatures. (Ship date is
indicated on the product label.)
Frozen (－70°C ~ －90°C): 9 months after the ship date.
Refrigerated (+2°C ~ +10°C): 4 days after placing it in a refrigerator.
■Specifications
Items Measured: pH, pCO2, pO2
Content: 3 levels, 2 ampoules for each level (1.5 ml / ampoule), total of 6 ampoules
Reference Material Institute for Clinical Chemistry Standards (ReCCS)
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Certified Reference Material for Blood Gas
JCCRM 621-4
Certificate of Analysis
■Certified Values and Expanded Uncertainties
Certified values and expanded uncertainties for this Certified Reference Material for Blood Gas (JCCRM
621-4) are shown below.
The certified values for pH, pCO2, pO2 differ depending on the gas equilibration temperature. Use the
certified values with the gas equilibration temperature of 37°C or 30°C.
Table 1 Gas equilibration temperature for the reference material: 37°C Measured temperature: 37°C
Item
Certified values & Expanded uncertainties
Unit of measure
Level 1 Level 2 Level 3
pH 7.339 ± 0.022 7.445 ± 0.023 7.546 ± 0.022 -
pCO2 54.5 ± 1.3 38.5± 1.4 27.3± 1.1 mmHg
pO2 40.6 ± 1.4 61.7± 2.0 81.4± 3.0 mmHg
Differences in the oxygen buffering capacities of human blood and the bovine hemoglobin liquid by the mean values of the
differences detected by various measuring electrodes are corrected (The mean values for correction obtained using 7 blood gas
analysers were 0.5 (0.2 ~ 0.8), 0.7 (0.4~1.0), and 1.0 (0.7 ~ 1.3) mmHg for each respective levels, 1, 2, and 3).
Table 2 Gas equilibration temperature for the reference material: 37°C Measured temperature: 37°C
Item
Certified values & Expanded uncertainties
Unit of measure
Level 1 Level 2 Level 3
pH 7.299 ± 0.023 7.414 ± 0.024 7.526 ± 0.023 -
pCO2 61.3 ± 1.9 41.9 ± 1.7 29.4 ± 1.2 mmHg
pO2 47.0 ± 1.1 79.3 ± 2.7 105.1 ± 2.5 mmHg
Differences in the oxygen buffering capacities of human blood and the bovine hemoglobin liquid by the mean values of the
differences detected by various measuring electrodes are corrected (The mean values for correction obtained using 7 blood gas
analysers were 0.5 (0.2 ~ 0.8), 1.0(0.7~ 1.3), and 2.0 (1.5 ~ 2.5) mmHg for each respective levels, 1, 2, and 3).
Reference Material Institute for Clinical Chemistry Standards (ReCCS)
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The uncertainties shown in Table 1 and Table 2 are expressed as expanded uncertainties (U, 95%
confidence level) estimated according to ISO GUM: Guide to the Expression of Uncertainty in
Measurement. REFERENCE [4]. U were calculated by U = k x Uc, where Uc is the combined standard
uncertainty, and k is the coverage factor (k = 2.0). Here, Uc represents combined standard uncertainty
derived from measurements, homogeneity gas equilibration process, and between ampoule variation,
stability during storage, and correction to whole blood.
Note: Please refer to the ADDENDUM on page 4 for the maximum allowable limits of bias from certified
values for routine blood gas analysers.
■Measurement Method Used for the Certified Values
The certified values of pH were assayed using a pH electrode with a reference cell. This is the standard
reference method prescribed by the IFCC (REFERENCE [2]). The certified values of pCO2 and pO2
were measured using a standard blood gas analyzer calibrated by the standard tonometry method
according to the IFCC’s reference method procedure (REFERENCE [3]). Measurements were protormed
at the Reference Material Institute for Clinical Chemistry Standards (ReCCS).
■Preparation
Hemoglobin obtained by hemolysis of washed bovine red cells was sealed in an air-tight ampoule after
stabilizing its partial gas pressure. Its ionic strength, bicarbonate concentration, BE (Base Excess), and
total hemoglobin level were adjusted as to meet the specifications of this CRM (REFERECE [1]).
■Traceability
As a reference material for measuring the certified values of pH, we used a pH standard solution (pH
6.8408 ± 0.010 at 37°C, pH 7.3940 ± 0.010 at 37°C) prepared from the NIST Standard Reference
Materials (SRM 186-I-g, KH2PO4; SRM 186-II-g, Na2HPO4). For the tonometry of pCO2 and pO2, we
used 3 levels of primary standard gases (CO2 + O2, balance N2) certified by the accreditation body of
JCSS (Japan Calibration Service System). We also used a platinum resistance reference thermometer
calibrated by JCSS for standard tonometry and gas equilibration.
■Date of Certification
July 27 , 2016
Reference Material Institute for Clinical Chemistry Standards (ReCCS)
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ADDENDUM
 pO2 difference between human whole blood and bovine hemoglobin .
We used 7 different blood gas analysers from 3 different manufacturers (A ~ G). Human whole
blood and bovine Hb liquid were tonometered using the same standard gases. These samples were
measured and evaluated to determine the effect of the different oxygen buffering capacities on the
pO2 measuring electrodes. The charts below show the different pO2 values from the 2 different
tonometry gases. The results indicated that the differences between human whole blood and bovine
Hb were 0.3 ~ 0.8 mmHg and 0.5 ~ 2.4 mmHg for the theoretical pO2 values of 37 mmHg and 72
mmHg, respectively.
 Biases range from the certified values of routine blood gas analysers.
Table 3 Bias test results (see Reference [1])
pH pCO2 (mmHg) pO2 (mmHg)
≤ 30 30 ~ 50 50 ≤ ≤ 40 40 ~ 100 100 ≤
± 0.04 ± 2.0 ± 3.0 ± 4.0 ± 3.0 ± 5.0 ± 6.0
 Properties
Properties of this CRM are shown in the table below. The values were obtained by measuring the
level 2 of this CRM using a routine test method to verify that they meet the specifications for the
reference materials (Reference [1]).
theoretical value
pp
p O2
（theoretical value：37 mmHg)
30
35
40
45
A B C D E F G
Measuring devices
Bovine Hb
Human whole blood
pO2measured values（mmHg）
theoretical value
p O2
(theoretical value：72 mmHg)
65
70
75
80
A B C D E F G
Measuring devices
pO2measured values（mmHg）
Bovine Hb
Human whole blood
Reference Material Institute for Clinical Chemistry Standards (ReCCS)
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Table 4 Properties of JCCRM 621-4
Item Standards Reference Value Unit of Measure Method Used
Ion Strength 160 ± 20 151 mmol/kg Calculated from electrolytic concentration
Base Excess 0 ± 4 －1 mmol/L Nomogram
Total Hb Level 140 ± 20 140 g/L ICSH method (cyanmethemoglobin method)
MetHb Content Ratio ≤ 6 0.6 % Absorptiometry
REFERENCES
[1] Committee on Blood Gases and Electrolytes, Japan Society of Clinical Chemistry. Approved
Recommendation on JSCC Methods on the Preparation of Working Reference Material and
Evaluation and Calibration for the Determination of the Blood Gas Measurement, Clinical
Chemistry, 34, 148-159 (2005)
[2] Approved IFCC methods. Reference method (1986) for pH measurement in blood. Clin Chim
Acta 165:97-109 (1987)
[3] IFCC Method (1988) for tonometry of blood: Reference materials for PCO2 and PO2. J Clin
Chem Clin Biochem 27:403-408 (1989)
[4] Guide to the Expression of Uncertainty in Measurement, ISBN 92-67-10188-9, 1st Ed. ISO,
Geneva, Switzerland (1995)
Provider of JCCRM 621-4:
Reference Material Institute for Clinical Chemistry Standards (ReCCS)
Hirohito Umemoto, President
http://www.reccs.or.jp/
1-3-3 Azaminominami, Aoba-ku, Yokohama
225-0012 , Japan
Tel (general inquiry and orders): 81-44-850-3140 Fax: 81-44-850-3141
Tel (technical inquiry): 81-45-507-6145 Fax: 81-45-530-9036
*No part of this Certificate of Analysis shall be reproduced without prior approval.