[en] Nuclear forensics refers to the application of science — in particular nuclear science —within the forensic science field. It is no longer a concept but a working tool, although it is still regarded by some as an emerging discipline that connects nuclear science and forensic science. Nuclear forensics is currently used effectively and reliably to prevent and respond to nuclear security events which involve nuclear and other radioactive material out of regulatory control. Its applications are critical in nuclear security systems to determine the data characteristics (i.e. signatures) of nuclear material subject to law enforcement investigations. This session was dedicated to papers on nuclear material signatures that highlighted and presented current work and developments or future expectations demonstrating the potential of nuclear forensic science

[en] Removal of known insecticide Heptachlor (HPTC) in methanol solution by gamma-rays under varied experimental conditions has been optimized. Air saturated solution of HPTC was irradiated at x-rays dose from 1 to 10 kGys. The extent of radiolytic degradation was monitored by reversed phase high performance liquid chromatography (HPLC) coupled with UV detector. At dose of 10 kGys gamma 98 % of HPTC was degraded. The degradation of HPTC occurs by CH/sub 3/O and CH/sub 2/OH radicals generated by methanol radiolysis. It is concluded that gamma-rays can remove Persistent Organic Pollutants (POPs) form environmental matrices. It can decrease the harmful properties of these POPs by their transformation into less resistant fragments to biological / natural elimination in the aquatic atmosphere. (author)

[en] A sensitive and specific method for uranium(6) determination using reverse phase ion-pair high performance liquid chromatography with UV detector has been developed. The developed method has been applied for the determination of uranium in a synthetic sample containing most of the interfering ions. Except iron most of the elements and anion which often interfere in uranium assay do not interfere in the present method. Interference of iron is masked by addition of 5mM/1 EDTA solution to the sample

[en] Monitoring, removal and management of toxic chemicals is an essential area of study regarding sustainable progress. Different approaches are adopted to eliminate these water born toxics from water and waste water. Among these gamma radiolytic is an emerging option. This ionization radiation generates highly reactive radicals that reacts with pollutants and hence eliminates these. A solid-phase micro-extraction (SPME) procedure has been developed for the successful preconcentration of organic pollutant irradiated water. A SPME fused-silica fiber coated with Polyacrylate was used as a probe to extract the organic pollutant after irradiation. In this reference, degradation of priority organic pollutant methoxychlor (1, 1, 1-Trichloro 2, 2-bis (p-methoxyphenyl) ethane, in water by gamma irradiation under varied experimental conditions has been investigated. The degree of gamma radiolytic degradation was monitored by HPLC-UV and GC-MS. For 4 kGy and 5 kGy gamma radiation dose at a rate of 200 kGyh/sup -1/ greater or equal to 95 % and 98 % MXC was degraded respectively. The degradation products were identified by Mass Spectrometry after comparing their MS spectras with the NIST 98 library. The major degradation occurs via dechlorination, dehydro chlorination, by the detachment of methoxyphenyl from MXC and by interaction of other radicals generated by the water radiolysis. (author)

[en] Application of gradient elution high performance liquid chromatography (HPLC) has been investigated for the probable analysis of PAHs in domestic and waste water. For this purpose extremely low quantities of four individual PAHs have been pre concentrated on polymeric resin and activated carbon. Various organic solvents have been tested as desorption solvents for the removal of PAHs. Recoveries of PAHs on both adsorbents have been evaluated for preconcentration and sample clean up purposes. (author)

[en] Ion selective electrode technique is an effective analytical approach for detecting or assaying various ions of interest. Broadly it can be classified into glass, liquid and polymer type membrane electrodes. Among these, polymer based membrane sensors are relatively easy to manufacture and can be designed as per requirement, particularly regarding miniaturization. The main source of ammonium ions in environment is the biodegradation of bio waste and chemical industry. Detection of ammonium ions is of primary importance regarding the biological activity of water reservoirs/marine life. The available photometric techniques can monitor ammonium ions effectively, however, disadvantages like sample processing and chances of contamination exist. In the present study a potentiometric ammonium ions transducer based on PVC-non actin membrane has been developed and optimized. Its effective use in the development of bio sensors has been proposed. These types of bio sensors are fabricated by immobilizing appropriate enzyme for a particular bio product. The end product of the catalysis is sensed by the transducer. (author)

[en] Acute and chronic effects of lead on human health are well documented. Tin is being used extensively for the protective coating/plating of cans, which are used in food preserving industry. Tin of different purity is available in the market and it is suspected that lead may be one of the major impurities which might contaminants the packed food on its long storage. Spectrophotometric method using dithizone as a chromagenic commercial tin samples was in the range of 300-600 micro g/g. Lead levels of the analyzed samples determined by spectrophotometric method, are in close agreement with the results obtained using atomic absorption spectrometry. (author)

[en] The gamma radiation-induced degradation of environmental pollutant methoxychlor in water was investigated. A ⁶⁰Co gamma radiation source with a dose rate of 372 Gy h^-1 was used for gamma irradiation of 1 mg L^-1 and 10 mg L^-1 methoxychlor in water with a varied absorbed dose of 1-5 kGy. A single step clean up and pre-concentration procedure based on solid phase micro-extraction was optimized. The extent of radiolytic degradation was monitored by reversed phase HPLC-UV and GC-ECD. The trace and ultra trace level degradation products were identified using GC-MS-SPME by comparing their mass spectra with the NIST 98 m mass spectral library. Most of the generated products for 4 kGy dose are substituted chlorophenols. The reaction pathways of these substituted chlorophenols and benzophenone formation are also proposed. However, generated chlorophenols disappeared along with methoxychlor for an absorbed dose of 5 kGy. The attained degradation of methoxychlor is ∝ 95% that reflects the potential use of ionization radiation for wastewater treatment. (orig.)

[en] The speedy industrialization and urbanisation without proper management of the general industrial and domestic waste have created at number of environmental problems. As alarming situation has been developed in the developing countries where domestic and in particular industrial waste is polluting surface and ground water including water reservoirs, which are the main sources of drinking water. According to safe drinking water act, EPA USA was classified in the twenty-three categories of organic pollutants, which are of main concern regarding quality of drinking water. Among these are also the polycyclic aromatic hydrocarbons (PAHs). Due to the carcinogenic and mutagenic character of PAHs, their presence in drinking and wastewater is of high concern regarding environmental investigations. Oil refineries, tanneries, electroplating units mainly discharge the pollutants, photographic processing labs and coal refining related industries. Due to their hydrophobicity, low solubility in water and high molecular weights, these accumulate in sediments and persist because of their stability. In spite of low solubility of PAHs in water relatively high level of these compounds have been found in water bodies. It might be due to adsorption of PAHs on particulate matter or their solubilization by micelles. (author)

[en] Monitoring of air-born organic and organic pollutants have always been a subject of concern to the environmentalists. Gases in particular Co/sub 2/, N/sub 2/O ad C/sub 4/ are responsible for global warming and have indirect impact on the environment. These gases are generally analyzed by gas chromatography. However on-site monitoring using this technique in rather difficult and it requires reasonable instrumental handling experience. The infrared-based technique is not only simple rather it also offers on advantage of on-site monitoring of a pollutant and eliminates the tedious job of sampling and its preservation. In the present work experimental conditions have been optimize for the selective detection of major global warming agents. Independent gas mixtures of Co/sub 2/, N/sub 2/O and C/sub 4/ have been prepared in pure helium gas by partial pressure method. The measured response of varied amount of each gas is found to be linear. The interference of these gases in presence of each other is also investigated. In this reference, gas mixtures of the gases are prepared considering the relevant concentration of each gas in the ambient air. The monitoring was found almost interference free at ambient concentration of these gases. The reliability can further be improved by incorporating the concentration trend of these gases. The reliability can further be improved by incorporating calibrated gas standard mixtures. (author)