The organization of national PTs in China - Wang Hong, Institute of Agricultural Resources and Regional Planning (IARRP) of Chinese Academy of Agricultural Sciences (CAAS) 4th Asian Soil Laboratory Network (SEALNET) meeting (online), 30 June - 2 July 2020

1. The organization of national PT in China
Dr. Wang Hong
Institute of Agricultural Resources and Regional Planning,
Chinese Academy of Agricultural Sciences
E-mail: wanghong01@caas.cn；gjhf@caas.cn
Tel: 86-10-82108648；86-10-82106196
June 30-July 2, 2020

2. CNCA is the management department of the qualification certification of
national inspection and testing institutions.
It’s role is to exercise administrative responsibilities of undertaking unified
management, supervision and overall coordination of certification and
accreditation activities across the country.
Certification and Accreditation Administration of
the People’s Republic of China (CNCA)
Main Operation
•China Compulsory Certification
•Voluntary Product Certification
•Management System Certification
•Service Certification
•Accreditation work

3. In March 2006, CNCA announced the implementation measures
of laboratory proficiency testing, which provides institutional
guarantee for the establishment of a national management and
standardization of PT.
Two kinds of National projects of PT
A projects (Compulsory)
The qualification certificate for inspection and testing institutions
issued by CNCA must participate in it.
B projects (Voluntary)
CNCA encourages inspection and testing institutions to participate
voluntarily in it.

4. China National Accreditation Service for Conformity
Assessment(CNAS)
China implements a unified accreditation system in
accordance with international practice. CNAS is the
national accreditation body established and authorized by
CNCA to take overall responsibility for the accreditation
on certification bodies, laboratories, inspection bodies and
other conformity assessment bodies under the provisions
of Regulations of the People’s Republic of China on
Certification and Accreditation.

5. CNAS is the member of International Accreditation Forum (IAF) and
International Laboratory Accreditatin Cooperation (ILAC), and has signed the
IAF Mutilateral Recognition Agreement (IAF MLA) and ILAC Mutual
Recognition Arrangement(ILAC MRA).
CNAS for conformity assessment has been a part of
international accreditation multilateral recognition
system, and is playing an important role in it.

6. Accredited Bodies by CNAS in China
◆ Accreditation of Testing Laboratories
◆ Accreditation of Calibration Laboratories
◆ Accreditation of Medical Laboratories
◆ Accreditation of Proficiency Testing Providers
◆ Accreditation of Reference Material Producers
◆ Accreditation of Laboratory Safety
◆ Evaluation of Good Laboratory Practice

7. CNAS’s documents in accordance with the relevant international
standards and technical requirements

8. Which laboratories or companies can provide PT?
ISO/IEC 17043:2010“Conformity
assessment - General requirements for
proficiency testing”
Accreditation Criteria and Rules for PT Providers in China

9. China NIL Research Center for PT

10. Proficiency Testing Providers
ISO/IEC 17043:2010“Conformity assessment - General requirements
for proficiency testing”

12. Problem：PT providers can not supply enough items of
agricultural soils to the testing laboratories

13. The requirements of samples for PT

15. The following are industry accepted values for evaluating Z-scores
and En numbers.
Z-scores
|z| ≤ 2 = satisfactory performance
2 < |z| < 3 = questionable performance
|z| ≥ 3 = unsatisfactory performance
En:
En ≤ 1 = satisfactory performance
En > 1 = unsatisfactory performance
If PT performance results are satisfactory?
Where U²lab = participant laboratory
test data uncertainty,
U²ref = independent laboratory test
artifact assigned value uncertainty.
Where x = participating laboratory
test data, X = test artifact assigned
value,s = measure of variability

16. 1) CNAS encourages the testing laboratories to attend PT verification to prove
their ability.
2) The testing laboratories should report to CNAS information on its
participation in PT.
3) CNAS set a rule to stipulate the minimum requirements for the testing
laboratories to participate in PT verification.
PT POLICIES
The requirements of CNAS
Soil chemical analysis : one
times/item/2year

17. The flow chart showing the activities of PT
http://www.eeaa.gov.eg/eimp/index.html

18. • Soil PT organized by Ministry of Agriculture and
Rural Affairs
Year Items
2007 Total N and K, heavy metals Pb and Cd
2008 Heavy metals Hg and As
2009 Heavy metals Hg and As
2010 Heavy metals Pb and Cd
2011 Heavy metals Pb , As, Cu and Cd
2012 Heavy metals Pb and Hg. Available Fe and Zn
2013 Heavy metals Pb , As, Cu and Cd
2014
Available Fe and B
Heavy metals Pb and As
2015 Heavy metals Pb , Cd, Zn and Hg
2016 Heavy metals Cd and As
2017 Heavy metals Cd,Pb and Ni
2018 Heavy metals Zn, Cu and Hg
2019 Heavy metals Cd, Ni and Hg

19. From 2007 to 2019, Ministry of Agriculture and Rural Affairs
provided PT for the technical capability of detecting soil
heavy metals and nutrient in different laboratories
36 38
32
26 25
34 32
27
33
47
61
96
125
0
20
40
60
80
100
120
140

20. Soil samples of PT
performance in our
lab, which is stored in
the dryer

21. Sample No.
N Kjeldahl (%) pH
Replicate Mean Replicate Mean
G-L0-1-033
0.056
0.055
5.33
5.34
0.054 5.34
0.054 5.35
0.055 5.34
G-L0-1-133
0.174
0.176
5.26
5.26
0.175 5.26
0.179 5.27
0.176 5.25
G-L0-1-233
0.273
0.272
6.68
6.68
0.273 6.68
0.272 6.67
0.270 6.67
CRM1 test
0.078
0.077
7.98
7.99
0.076 8.00
CRM2 test
0.202
0.201
6.00
5.99
0.200 5.97
Certified value
CRM1
0.077±0.003 8.15±0.08
Certified value
CRM2
0.197±0.006 6.08±0.06
FAO PT’s results of Total N and pH by our lab in 2019
CRM, Certified Reference Material

22. PT is a scientific and effective technical means for the
testing laboratories to prove the testing ability.
In China, CNAS has set series rules to manage PT
providers and PT Implementation mainly according to ISO
standards and guidelines.
There are compulsory and voluntary projects of PT for the
testing laboratories.
Summary

23. Thanks for your attention