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Nahar Singh VN Ojha Nijhuma Kayal Tarushee Ahuja Prabhat K Gupta 《Chemistry Central journal》2011,5(1):17
Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate
and precise measurement of arsenic in suspended particulate matter (SPM) is of prime importance as it gives information about
the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance
is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability
of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis.
The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the
main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various
potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of
Delhi (National Capital of India) for quantification of arsenic content in SPM samples with uncertainty budget following sampling
by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG). In the measurement of arsenic in SPM samples
so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties.
The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the
final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis,
weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that
during the period from 31st Jan. 2008 to 7th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m3 with 95% confidence level (k = 2). 相似文献
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DS Zhulai SA Bugaychuk GV Klimusheva TA Mirnaya VN Asaula VI Handziuk 《Liquid crystals》2017,44(8):1269-1276
The class of thermotropic ionic liquid crystals (LCs) of the metal alkanoates possesses a number of unique properties, such as intrinsic ionic conductivity, high dissolving ability and ability to form time-stable mesomorphic glasses. These ionic LCs can be used as nanoreactors for the synthesis and stabilisation of different types of nanoparticles (NPs). Thus, some semiconductors, metals and core/shell NPs were chemically synthesised in the thermotropic ionic liquid crystalline phase (smectic A) of the cadmium octanoate (CdC8) and of the cobalt octanoate (CoC8). By applying the scanning electron microscopy, the cadmium and cobalt octanoate composites containing CdS, Au, Ag and core/shell Au/CdS NPs have been studied. NPs’ sizes and dispersion distribution of the NPs’ size in the nanocomposites have been obtained. 相似文献
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A new method for the determination of metals in waters by flame atomic-absorption spectrometry is described. The metals are retained by water-soluble polymers in a membrane filtration cell and the factors which influence their determination are discussed. The method has been applied to the determination of Ni, Cu, Zn, Hg and Cd in drinking and river water with poly(ethyleneimine) and its thiourea derivative as complexing polymers. The metals were determined in the aqueous concentrate after a 250-fold preconcentration by 2% polymer solution at pH 7. The metal recoveries were at least 92%, and the limits of detection (ng/mg) were 0.012 for Cu, 0.006 for Zn, 0.03 for Ni, 0.004 for Cd and 0.0001 for Hg (cold vapour method). When a new type of membrane filtration cell is used even higher preconcentration factors can be achieved and lower concentrations can be determined. 相似文献
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