Authors:S. Waheed, S. Rahman, S. Husnain, and N. Siddique
Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy methodology was developed to characterize
the hazardous and other inorganic trace element constituents in new and used domestic plastic food containers. INAA due to
its non destructive, highly sensitive, multielement and low detection limits characteristics was found to be a good technique
for the characterization of polymeric products. Through the variation of irradiation, cooling and counting protocols Al, Ba,
Br, Co, Cr, Eu, Fe, Hg, K, Mn, Na, Nd, Sb, Sc, Th, Ti, V and Zn were determined, while Atomic Absorption Spectroscopy was
used as complementary technique to quantify toxic inorganic elements such as Cd, Pb and Cu. These elements are thought to
originate from the polymer manufacturing processes. It was found that there was gradual increase in the concentration of most
of these elements from new to used plastic samples. Moreover it was also observed that these inorganic elements are present
in higher concentrations in the lower grade containers as compared to the high quality containers. It was also observed that
the good quality containers even with the long usage do not degrade to such an extent as the low quality containers.
Authors:N. Siddique, A. Majid, M. Chaudhry, and M. Tufail
The elements Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in dust samples collected from air conditioner (AC) filters from
15 commercial sites of Lahore using flame atomic absorption spectroscopy (FAAS). The elements Cr, Mn and Zn were also determined
using instrumental neutron activation analysis (INAA). The results obtained showed that higher amounts of these metals were
measured in these dust samples than normally found in soil. This was especially true for Cd, Cu, Pb and Zn. Generally the
amounts of Cd, Cr and Mn did not vary throughout the city of Lahore but the amounts of the traffic related Cu, Pb and Zn elements
had the more variable ranges of 30–140, 30–230 and 74–2810 mg/kg respectively. The concentrations obtained for Cr, Mn and
Zn by INAA were found to be higher than those obtained using FAAS. Analysis of the data obtained showed the digestion procedure
employed to be the possible cause for this occurrence. It was also found that Mn was being over-estimated by INAA due to the
interference from the Mg peak.
Authors:N. Siddique, S. Waheed, M. Daud, A. Markwitz, and P. Hopke
Over a 1,000 pairs of coarse and fine filters were collected using Gent samplers and polycarbonate filters from three sites
in Islamabad from the period 1998 to 2010. The black carbon in these samples was determined by reflectance measurement while
their elemental composition were determined using the techniques of instrumental neutron activation analysis, ion beam analysis
and X-ray fluorescence spectrometry. Islamabad is a well planned and relatively small city as compared to Lahore or Karachi
therefore its air quality is better than the air quality of other major Pakistani cities. It was found that the new air quality
standards being implemented by the Pakistani government on the 1st of January 2012 may not be attained even in Islamabad without
the implementation of control and remedial measures. An overview of the elemental data obtained and calculation of enrichment
factors shows that the particles in Islamabad originate from re-suspended soil, vehicular emissions and coal combustion. However
further work is required for identification of pollution sources and their origin.
Authors:N. Siddique, S. Waheed, M. Daud, A. Rahman, and S. Ahmad
Tuna fish flesh homogenate, IAEA-436, was received under the IAEA Analytical Quality Control Services (AQCS) intercomparison
programme. Instrumental neutron activation analysis (INAA) was used to determine Al, As, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe,
Hg, K, Mg, Mn, Na, Rb, Se, Sb, Sm, and Zn in this proposed reference material (RM). IAEA-407 (Fish Homogenate) and NIST-SRM-1572
(Citrus Leaves) were used for quality assurance (QA) purposes. Due to the very low levels of most elements in IAEA-436, large
discrepancies were observed between our results for IAEA-436 and data cited by the IAEA.
Authors:S. Waheed, N. Siddique, Q. Hamid, and M. Chaudhry
INAA and AAS techniques have been employed to determine 40 elements in soil of a municipal waste dump in sector H-11, Islamabad.
Background soil was also analyzed to study the extent of contamination of the dump site soil. Most of the major elements in
these soils represented the geochemical composition of the soil in this area. The enrichment factors for quantified elements
identified high Sb and Mg contents that could be attributed to the presence of PET and food materials in the waste. Geo-accumulation
Index (Igeo), Pollution Index (PI) and the Integrated Pollution Index (IPI) have also been calculated for all elements. The values for
these indices show that municipal waste has distorted the soil ambiance and the soil of waste dump site is slightly to moderately
polluted as compared to the background soil. The dump soil was found to be moderately polluted by the elements Ba, Br, Ga,
Rb, Zn, Ni and Pb. Significantly high Cu, Mg and Sb contamination was observed for the waste soil that is likely to pose an
environmental issue if current waste disposal procedures are continuously employed.
Authors:N. Siddique, S. Waheed, A. Rahman, and S. Ahmad
A national intercomparison exercise was conducted to remove inconsistencies and improve analytical procedures in the measurement
of hafnium and zirconium in zirconium ores. The ZH-A series of reference samples, prepared at the Pakistan Institute of Nuclear
Science and Technology (PINSTECH), were used for this purpose. It was observed that measurement errors decreased with increasing
Hf concentration (~298-17500 ppm) for most techniques, especially for AAS due to the sample preparation procedure required
for this technique. Of all the tested techniques most reliable results were obtained with neutron activation analysis (NAA)
for the measurement of Hf and Zr in such matrices.
Authors:S. Waheed, N. Siddique, A. Rahman, J. Zaidi, and S. Ahmad
instrumental neutron activation analysis (INAA) has been employed to determine 19 essential and other trace elements of fourteen
fruits harvested in Pakistan. Most of the fruits investigated contain substantial Ca, Cl, Fe, Mg, K and Na concentration levels.
Fruits were found to be an adequate source of Co and Fe. Winter season provides a variety of fruits with highest adequacy
for most of the essential elements while the fruits ingested in the summer season provide the minimum nutrient adequacy for
these elements with the exception of Cl.
Authors:N. Siddique, Sabiha-Javied, S. Waheed, and M. Tufail
Analysis of geological materials requires the use of matrix specific reference materials (RMs). Phosphate rocks (PR), the
basic ingredient of phosphate fertilizers, are very important in agriculture. A project was undertaken to study the PRs of
the Hazara Deposits of Pakistan. Due to the unavailability of phosphate rock reference materials (PR-RMs) with a large number
of certified elements, validation of the results was problematic when carrying out elemental analysis of PR samples and their
derived products. Therefore a parallel study was performed to determine the composition of three phosphate based RMs; BCR-RM-032
(Natural Moroccan Phosphorite), IAEA-434 (Phosphogypsum) and PRH (a local PR-RM from the Hazara Deposits of Pakistan). Instrumental
Neutron Activation Analysis was used for this purpose and more than 30 elements including rare earth elements were determined
in the three PR samples.
Authors:S. Waheed, N. Siddique, M. Arif, M. Daud, and A. Markwitz
Size fractionated PM2.5 and PM2.5–10 airborne particulates collected from the airport housing society site in Rawalpindi were characterized using the non destructive
ion beam analysis method. Proton induced X-ray emission and Proton induced gamma ray emission were employed to quantify 28
trace elements in fine and coarse filter samples. The average PM2.5 and PM2.5–10 masses were found to be 15.7 and 144 μg/m3, respectively which, when combined exceed the Pakistani limit for PM10 of 100 μg/m3. The average black carbon (BC) content was found to be 3.49 and 5.95 μg/m3 corresponding to 23.8 and 4.30% of the fine and coarse masses, respectively. The reconstructed mass (RCM) was calculated
for both particle modes using 5 pseudo sources, namely soil, sulfate, smoke, sea salt and BC. It was found that 5 sources
could account for 80.6 and 49.0% of the fine and coarse masses, respectively. The low value of RCM for the coarse mode may
imply a much higher organic content. The major sources contributing to the fine mode were soil, sulfate and BC. Similarly
for the coarse mass fraction it was found that soil was the major source whereas the sulfate and BC sources did not contribute