Instrumental neutron activation analysis and particles induced x-ray emission for monitoring airborne particulate matter in Indonesia

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1 M. Santoso et al. Proceeding of The International Seminar on Chemistry 28 (pp. 3-8) ISBN Instrumental neutron activation analysis and particles induced x-ray emission for monitoring airborne particulate matter in Indonesia Muhayatun Santoso *, Philip K Hopke 2, Andreas Markwitz 3, Diah Dwiana Lestiani Center of Nuclear Technology for Materials and Radiometry, Jln. Tamansari 7 Bandung 2 Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY , United States 3 Institute of Geological and Nuclear Sciences (GNS), 3 Gracefield Road, P.O Box 3-32, Lower Hutt, New Zealand * hayat@bdg.centrin.net.id Abstract Nuclear techniques have been used in quantification of environmental pollutant. Instrumental neutron activation analysis (INAA) and Particle Induced X-ray Emission (PIXE) have been turned out to be particularly useful in the analysis of airborne particulate matter. Nuclear Energy Agency of Indonesia has carried out the monitoring air quality especially for airborne particulate matter using nuclear analytical techniques. Sampling of airborne particulate matter was done twice a week for 24 hours in an urban area Bandung and in a suburban area Lembang, Indonesia. The samples were collected using a Gent stacked filter unit sampler in two size fractions of < 2.5 µm (fine) and 2.5 to µm (coarse). The samples were analyzed for elemental concentrations by INAA at TRIGA 2 Bandung reactor and PIXE at Institute of Geological and Nuclear Sciences, New Zealand. The validation of INAA method was done using NIST SRM 648 airborne particulate matter. Both techniques provide more than 2 significant elements for identification the possible sources of atmospheric aerosol.. The results demonstrated that INAA and PIXE have a high sensitivity, very precise value for many trace elements in APM samples. Keywords: instrumental neutron activation analysis, particle induced X-ray emission, airborne particulate matter Introduction Urbanization, industrial development and growth in mobility have deteriorated air quality. Urban air pollution poses significant threats to human health and the environment and the quality of life of millions of people. Particulate matter has adverse health effects, affecting both the respiratory and cardiovascular systems (Dockery et al., 993; Katouyanni, 25). They also have serious influence on climate forcing, global warming and visibility. (Albriton, 2; Cohen et al., 24). In Indonesia, there is some routine air pollution monitoring, but the focus is still in total suspended particulate (TSP) or PM (particles with aerodynamic diameters less than µm). The long term published data on PM 2.5 concentrations and compositions of airborne particulate matter is still scarce. Kim Oanh et al., (26) presents summaries of PM 2.5 and PM in six cities in Asia, namely Bandung, Indonesia, Bangkok, Thailand, Beijing, China, Chennai, India, Manila, Philipina, and Hanoi, Vietnam. Other also reported on the composition and source apportionment of fine and coarse particle samples collected in Bandung and Lembang, Indonesia between 22 and 24 (Santoso et al., 28). However, particulate matter compositional data has seen only limited use for the determination of possible sources. For appropriate air quality management, the source of particles air pollution must be known qualitatively. For this reason, the nuclear analytical techniques such as instrumental neutron activation analysis (INAA) and particle induced X-ray emission (PIXE) is widely used to analysis the filter samples of airborne particulate matters. Nuclear techniques have been applied to the characterization of particulate matter from air pollution in around the world (e.g Cohen et al., 24; Biswas et al.,23; Chueinta et al., 2; Begum et al., 25; Hien et al., 25; Chung et al., 25; Trompetter et al., 22) Their simultaneous measurement, multi-elemental capabilities, high sensitivity, short analysis time and non destructive properties make them ideal for this type of work. The air particulate samples in filter may only contain a total sample mass of µg, thus providing an extremely small sample for analysis by other more conventional method. Furthermore, the large numbers of samples obtained from air quality monitoring can be most efficiently characterized by multi-elemental techniques such as INAA and PIXE. This technique can produce large data sets for statistically 3

2 M. Santoso et al. Proceeding of The International Seminar on Chemistry 28 (pp. 3-8) characterizing pollution sources as well as estimating different source contributions which is critical to understanding air pollution and air quality management. This paper discussed the application of INAA and PIXE in characterization the airborne particulate matter in Bandung and Lembang, Indonesia. The work focused on particles with aerodynamic diameter less than 2.5 µm (fine particles FPM) and between 2.5 and µm (coarse particles CPM). Sampling and elemental concentration determination Sampling for urban site was conducted in Nuclear Technology Center for Materials and Radiometry in Bandung at The roof height is 4.3 m above ground level and the intake nozzle of the sampler is located.8 m above the roof. The intake is about 6 m away from the roadside. Bandung is located at latitude 6.53 S, longitude 7.36 E and 63 m above sea level. It is a province city of West Java categorized as industrial city with high population more than 2.6 million inhabitants in area of approximate km 2. Many small scale factories are also located around the city. Fig. shows the location of the sampling sites in Bandung and its surrounding area. Sampling at the suburban site was conducted in Lembang (6.49 S and 7.36 E) on the roof of Beareau of Meteorological and Geophysical s building about 6 m above ground level and about km from nearby street and 5 km from Tangkuban Perahu Volcano. Whereas Lembang is a small village about 6 km from sampling site in Bandung, 3 m above sea level, close to Boscha observatory. Samples of FPM and CPM were collected twice a week for 24 hours at a flow rate of 5-8 L/min at both sites from January 24 to December 25, using a Gent stacked filter unit sampler in two fractions of < 2.5 µm fine and 2.5 µm coarse sizes [Hopke et al., 997]. Airborne particulate samples were stored in clean polyethylene bag and placed in clean room at the relative humidity below 6% and temperature of 8 25ºC for mass stabilization. The samples collected in 24 were analyzed for elemental concentration by INAA. The irradiation procedure and the counting have been written elsewhere (Santoso et al., 26). Elemental analysis of samples collected in 25 was performed using PIXE at the Institute of Geological and Nuclear Sciences (GNS), New Zealand. The X-ray spectra were analyzed using the computer code GUPIX (Maxwell et al., 995). Calibration of the PIXE system was performed by irradiating the suitable MicroMatter thin target standards (Begum et al., 24). Results and Discussion The NIST standard reference material SRM 648 airborne particulate matter were analyzed in the same experimental conditions used in the sample analysis as method validation to evaluate the precision and accuracy of the results by INAA. The result of SRM 648 analyses were consistent with the value quoted in the NIST certificate, are shown in Figure 2. All samples are collected during the weekdays. The elemental concentration measured in FPM Bandung and Lembang are shown in Figure 3, 4, 5 and 6. The INAA technique was used to analyse for the 24 elements Al, Ag, As, Br, Ca, Cl, Co, Cr, Cs, Fe, Hg, I, K, La, Mg, Mn, Na, Sb, Sc, Se, Sm, Ti, V, and Zn. While, the PIXE technique was used to analyse for the 2 elements Al, As, Br, Ca, Cl, Co, Cr, Cu, Fe, I, K, Mg, Mn, Na, Pb, Sc, Ti, V and Zn. The result showed that by INAA and PIXE, these methods can determine more than 2 elements altogether. Figure Map of sampling site 4

3 the M. Santoso et al. Proceeding of The International Seminar on Chemistry 28 (pp. 3-8), Concentration (mg /kg),, Al As Br Cl Co Cr Fe I La Mn Na Sb Sm Ti V Zn Element Figure 2 SRM 648 Airborne particulate matter result analysis Some elements that can not easily be analyzed by INAA such as Si and Pb are well analyzed by PIXE. On the contrary, other element such as I, Na and K by INAA is better than PIXE. By PIXE, the fit error has resulted more than 5% for I, Na, V and Co. Elements Cs, Co, Sb, Sc, Se, SM, La, Hg were also well analyzed by INAA. Those elements that have been determined have significant role to understand and observed the indication of potential source by correlating each elements. Furthermore, the range of elements observed indicates a variety of different fine particle sources. For Examples, Al, Si and Ti from windblown soil, Na and Cl from seasalt, Mn, Fe, Cu and Zn from industry, Pb and Br from motor vehicles, and K from wood burning. 8 Elemental conc. (ng/m3) Al Ag As Br Ca Cl Co Cr Cs Fe Hg I K La Mg Mn Na Sb Sc Se Sm Ti V Zn Figure 3 Whisker plot of elemental concentration di FPM Bandung 24 by INAA 8 Elemental conc (ng/m3) Al Ag As Br Ca Cl Co Cr Cs Fe Hg I K La Mg Mn Na Sb Sc Se Sm Ti V Zn Figure 4 Whisker plot of elemental concentration di FPM Lembang 24 by INAA 5

4 M. Santoso et al. Proceeding of The International Seminar on Chemistry 28 (pp. 3-8) In Figure 3 and 4, the analyzed data for elemental concentration by INAA is presented. By making two different irradiation condition and four gamma-ray counts after appropriate decay times, up to 2 elements could be determined. By INAA major elemental species like S and Si are not measured. In order to obtain a chemical fingerprint of a given fine particle source, two things must be determined firstly which elements characterize the fingerprint and secondly the relative proportions of each of those elements which provide the signature for the fingerprint at a sampling site. The results obtained by INAA shows that fine paticulate samples have high concentration of K, Al, Ca, Fe, Na, Br and Cl. High concentration of K is assigned as emissions from biomass burning; Al, Ca and Mg are estimated as soil dust sources; Br is characterized from vehicle source; while Na and Cl from sea salt. Even though in this research, INAA method did not measure Pb concentration but characterization of vehicle sources can be done using concentration of bromine. In Figure 5 and 6 the analyzed data for elemental concentrations by PIXE is presented. They provided elemental information on a broad range of elements including F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Mo, I, Hg and Pb. Since some elements had a large number of fit error (%) or values below detection limit, data for only 2 measured elements were used in the data analysis. 24 Elemental Conc (ng/m3) Al Br Ca Cl Cr Cu Fe Ga I K Mg Mn Na Ni Pb S Si Ti V Zn Element Figure 5 Whisker plot of elemental concentration di FPM Bandung 25 by PIXE 24 Elemental conc (ng/m3) Al Br Ca Cl Cr Cu Fe I K Mg Mn Na Pb S Si Ti V Zn Element Figure 6 Whisker plot of elemental concentration di FPM Lembang 25 by PIXE 6

5 M. Santoso et al. Proceeding of The International Seminar on Chemistry 28 (pp. 3-8) (X ) 4 Elemental Conc (ng/m3) 3 2 Al As Br Ca Cl Co Cr Fe Hg I K La Mg Mn Na Sb Sc Sm Ti V Zn Figure 7 Whisker plot of elemental concentration di CPM Bandung 24 by INAA (X ) 6 5 Elemental Conc (ng/m3) Al Br Ca Cl Cr Cu Fe I K Mn Na Ni P Pb S Si Ti Zn Figure 8. Whisker plot of elemental concentration di CPM Bandung 25 by PIXE The results show that S is the major elemental spesies in fine particulate samples. High concentration of S is identified as secondary sulfate and motor vehicle sources. For CPM Bandung that analyzed by PIXE and NAA are also shown ini Figure 7 and 8. These results showed that PIXE and NAA have a high sensitivity, very precise value for many trace elements in APM samples. Other publication also made comparison between PIXE and NAA (Cohen et a., 996), the ratio of the fit for NAA to PIXE on the same samples is.97±. with coefficient of least squares fit R 2 =.99. This was excellent agreement as the analyses were carried out in different laboratories. This and other published studies (Cohen et al., 24: Cohen et al, 996) provides great confidences that the nuclear techniques are suitable for filter samples analysis. Conclusions In summary, PIXE and INAA techniques provides a very powerful, routine multi-elemental analysis method for particulate aerosol studies. The ability to provide elemental concentration information on all of the most significant elements can be applied for further information on source fingerprints and hence possible sources of particles in the atmosphere. 7

6 M. Santoso et al. Proceeding of The International Seminar on Chemistry 28 (pp. 3-8) Acknowledgements This study is supported by International Atomic Energy Agency (IAEA) and National Nuclear Energy Agency Indonesia (BATAN). References Begum, B.A., Kim, Eugene., Biswas, S.K., Hopke, P.K. 24. Investigation of sources of atmospheric aerosol at urban and semi-urban areas in Bangladesh. Atmospheric Environment 38: Begum, B.A., Biswas, S.K., Kim, E., Hopke, P.K., Khaliquzzaman, M. 25. Investigation of sources of atmospheric aerosol at hot spot area in Dhaka, Bangladesh. J. Air Waste Manage. 55: Biswas, S. K., Tarafdar, S. A., Islam, A., Khaliquzzaman, M., Tervahattu, H.and Kupiainen, K. 23. Impact of unleaded gasoline introduction on the concentration of lead in the air of Dhaka, Bangladesh. J. Air and Waste Management Association. 53: Chueinta, W., Hopke,P.K., Paatero, P. 2. Investigation of sources of atmospheric aerosol at urban and suburbun residential areas in Thailand by Positive matrix factorization. Atmospheric Environment 34: Chung, Y.S., Kim, S.H., Moon, J.H., Kim, Y.J., Lim, J.M., Lee, J.H. 25. Source identification and long term monitoring of airborne particulate matter PM2.5/PM in an urban region of Korea. J Radioanal Nucl Chem. 267: Cohen D.D, Gorton D., Stelcer E., Hawas, O. 24. Accelerator based studies of atmospheric pollution processes, Radiation Physics and Chemistry 7: Cohen D.D, Grahama M.B, Kondepudi R. 996 Elemental Analysis by PIXE and other IBA techniques and their application to source fingerprinting of atmospheric fine particles pollution, Nucl. Instr. and Meth. B 9: D.L. Albritton, L.G Meira Filho. 2. The third assessment report of working groups I of the intergovernmental panel on climate change, technical summary, IPCC, Shanghai, 7 2 January 2 Dockery, D.W, Pope, C.A, Xu, X., Spengler, J.D., Ware, J.H, Fay, M.E., Ferris, B.G.,Speizer,F.E., 993. An association between air pollution and mortality in six US cities, New England.Journal of Medicine 329: Hien, P.D., Bac, V.T., Thinh N.T.H. 25. Investigation of sulfate and nitrate formation on mineral dust particles by receptor modeling. Atmos Environ. 39: Hopke, P.K., Xie, Y., Raunemaa, T., Bieglski, S., Landsberger, S., Maenhaut, W., Artoxo, P., Cohen, D Characterization of Gent stacked filter unit PM sampler. Aerosol Science and Technology 27: Katouyanni K, 25. Long term effect of air pollution in Europe, Occupational and Environmental Medicine 62: Kim Oanh, N.T., Upadhayay, N., Zhuang, Y.H., et al. 26. Particulate air pollution in six cities: spatial and temporal distributions, and associated sources. Atmos Environ. 4: Maxwell, J.A., Teesdale, W.J. The GUELPH-PIXE Software Package II. Nucl Instrum Methods Phys Res B Beam Interact Mater Atoms.95: Santoso, M., Hopke, P.K., Hidayat, A., Dwiana, D., 28. Source identification of atmospheric aerosol at urban and suburban sites in Indonesia by positive matrix factorization. Science of Total Environ. 397: Santoso, M., Hidayat, A., Dwiana, D., 26. Instrumental Neutron Activation Analysis for Characterization of Airborne Particulate Matter. Proceeding of the Environmental and Technology Management Conference 26. Institute of Technology Bandung, Bandung, Indonesia Trompetter, W.J., Markwitz, A. 22. The New Zealand Ion Beam Analysis facility plays a key role in the analysis of ambient particulate matter, 6th Clean Air and Environment Conference, 8-22 August 22. 8