2017-12-28

Urban Aerosols

This environmental certified reference material (CRM) was developed and certified by the National Institute for Environmental Studies (NIES) for the determination of multi-elements in aerosol particulate matter.

Preparation of the CRM

The origin of this material is atmospheric particulate matter collected on filters in a central ventilating system in a building in Beijing city center. The collection period was 10 years, from 1996 to 2005. The particulate matter was recovered from the filters by mechanical vibration; a total of 3 kg was collected. The recovered material was sieved using a 32 μm sieve, and then homogenized. The sieved material (2 kg) was subdivided into 1031 pre-washed amber glass bottles with each bottle containing 1.5 g material. Then material was stabilized by 60Co irradiation (2.5 Mrad). The CRM production was conducted in accordance with ISO Guide 34.

Homogeneity

Twelve bottles were randomly selected from the entire batch and elemental analyses were carried out on the contents of each bottle using ICP-AES. The between-bottle standard deviation for each element was less than 3%. It was adjudged that the prepared material was sufficiently homogeneous for its intended use as a reference material.

Stability

The results of stability tests demonstrated that any long-term variations in the values of all the measured elements in the material were insignificant.

Certified and Reference Values

Elemental analyses were reported by 17 organizations (see below). Certified values are given for element mass fractions that were determined by at least two analytical methods, and were decided in accordance with ISO Guide 35 (Table 1). The uncertainty attached to the certified values is the expanded uncertainty using a coverage factor k = 2, corresponding to a confidence interval of approximately 95%. Reference values are given for elements with relative standard deviations of the mean of the analytical laboratory means of 6-10%, or with 3-9 laboratories contributing to the mean (Table 2). All certified and reference values were determined on an "as received" basis, that is, the values were determined without drying the material.

Table 1 Certified values of NIES CRM No. 28 Urban Aerosols

Element Unit Mass fraction Analytical method
Na % 0.796 ± 0.065 AAS, ICP-AES, INAA, XRF
Mg % 1.40 ± 0.06 ICP-AES, ICP-MS, XRF
Al % 5.04 ± 0.10 ICP-AES, ICP-MS, INAA, XRF
K % 1.37 ± 0.06 AAS, ICP-AES, XRF
Ca % 6.69 ± 0.24 ICP-AES, ICP-MS, INAA, XRF
Ti % 0.292 ± 0.033 ICP-AES, ICP-MS, INAA, PIXE, XRF
Fe % 2.92 ± 0.17 ICP-AES, ICP-MS, INAA, XRF
Zn % 0.114 ± 0.010 ICP-AES, ICP-MS, INAA, PIXE, XRF
 
V mg/kg 73.2 ± 7.0 ICP-AES, ICP-MS, INAA
Mn mg/kg 686 ± 42 ICP-AES, ICP-MS, INAA, PIXE, XRF
Ni mg/kg 63.8 ± 3.4 AAS, ICP-AES, ICP-MS
Cu mg/kg 104 ± 12 ICP-AES, ICP-MS, PIXE, XRF
As mg/kg 90.2 ± 10.7 HG-AAS, HG-ICP-AES, ICP-AES, ICP-MS, INAA, XRF
Sr mg/kg 469 ± 16 ICP-AES, ICP-MS, XRF
Cd mg/kg 5.60 ± 0.43 ICP-AES, ICP-MS
Ba mg/kg 874 ± 65 ICP-AES, ICP-MS, INAA
Pb mg/kg 403 ± 32 ICP-AES, ICP-MS, XRF
U mg/kg 4.33 ± 0.26 ICP-MS, INAA

AAS: atomic absorption spectroscopy
HG-AAS: hydride generation - atomic absorption spectroscopy
HG-ICP-AES: hydride generation-inductively coupled plasma-atomic emission spectrometry
ICP-AES: inductively coupled plasma-atomic emission spectrometry
ICP-MS: inductively coupled plasma-mass spectrometry
INAA: instrumental neutron activation analysis
PIXE: proton induced X-ray emission spectrometry
XRF: X-ray fluorescence spectroscopy

Table 2 Reference values of NIES CRM No. 28 Urban Aerosols

Element Unit Mass fraction Analytical method
Si % 14.9 Gravimetry, PIXE, XRF
P % 0.145 ICP-AES, XRF
S % 3.91 ICP-AES, PIXE
Cl % 0.807 INAA, PIXE
 
Be mg/kg 5.09 ICP-AES, ICP-MS
Sc mg/kg 10.7 ICP-AES, INAA
Cr mg/kg 65.6 ICP-AES, ICP-MS, INAA, PIXE
Co mg/kg 22.0 ICP-AES, ICP-MS, INAA
Se mg/kg 14.4 HG-AAS, HR-ICP-MS, ICP-AES, ICP-MS, INAA
Rb mg/kg 64.1 ICP-MS, INAA, XRF
Y mg/kg 21.9 ICP-AES, ICP-MS
Mo mg/kg 28.4 ICP-AES, ICP-MS, INAA
Sn mg/kg 21.5 ICP-MS
Sb mg/kg 20.1 HG-ICP-AES, ICP-MS, INAA
La mg/kg 32.7 ICP-AES, ICP-MS, INAA
Th mg/kg 11.1 ICP-MS, INAA

HG-AAS: hydride generation - atomic absorption spectroscopy
HG-ICP-AES: hydride generation-inductively coupled plasma-atomic emission spectrometry
HR-ICP-MS: high resolution inductively coupled plasma-mass spectrometry
ICP-AES: inductively coupled plasma-atomic emission spectrometry
ICP-MS: inductively coupled plasma-mass spectrometry
INAA: instrumental neutron activation analysis
PIXE: proton induced X-ray emission spectrometry
XRF: X-ray fluorescence spectroscopy

Precautions for Storage and Handling for Analysis

  1. This CRM should be kept tightly closed in its original bottle and stored in a desiccator at room temperature (≤30 ℃).
  2. Prior to weighing aliquots for analysis, the contents of the bottle should be shaken gently.
  3. A minimum sample intake of 0.02 g is recommended.
  4. Precautions should be taken to avoid inhalation of the material.
  5. Do not use for purposes other than research. When disposing of the material, adhere strictly to local laws concerning processing and disposal of waste materials.

Expiration Date of Certification

The expiration date for the certified values of this CRM is January 2028 assuming that the above mentioned storage conditions are adhered to. NIES will notify via its website if any changes in the values are recognized within the term of validity.

Collaborating Laboratories in Analysis

The certified and reference values for this CRM were based on the analytical values from the following participating organizations:
National Institute for Environmental Studies; Chikyu Kagaku Kenkyusho Co., Ltd; China Institute of Atomic Energy; Environmental Control Center Co., Ltd.; Green Blue Corporation; Idea Consultants Inc.; Japan Chemical Analysis Center; Japan Environmental Sanitation Center; Murata Keisokuki Service Co. Ltd; Musashi Institute of Technology; Naitoh Environmental Science Co., Ltd.; Nittech Research Inc.; Norwegian University of Science and Technology; Shimadzu Techno-Research Inc.; Sumika Chemical Analysis Service, Ltd.; University of Sheffield; University of Shizuoka, Institute For Environmental Science.

Organizations Cooperating in the Preparation of the Material

Institute for Reference Materials of the State Environmental Protection Administration, P.R. China; Japan International Cooperation Agency (JICA), The Shino-Japan Friendship Center for Environmental Protection Project Phase III JICA Expert Team.

Organization Responsible for Preparation, Certification, and Distribution

The Environmental Analytical Chemistry Research Laboratory within the Laboratory of Intellectual Fundamentals for Environmental Studies, NIES, takes entire responsibility for this CRM. Technical information and the latest research reports regarding this material can be obtained from the following address.

Reference

1 Development and certification of the new NIES CRM 28: urban aerosols for the determination of multielements
Anal. Bioanal. Chem., 391: 1997-2003 (2008)
Ikuko Mori, Zijie Sun, Miyuki Ukachi, Kimiyo Nagano, Cameron W.McLead, Alan G. Cox, Masataka Nishikawa

Appendix

Information that could be useful for handling this material is provided, though the values are non-certified.

Appendix:Fig. & Table