Recent Advances of the Asymmetric Bisazo Derivatives of Arsenazo and Phosphonazo as Chromogenic Reagents in Analytical Chemistry

1993 ◽  
Vol 12 (3-4) ◽  
Author(s):  
Jiao-Mai Pan ◽  
Chung-Gin Hsu ◽  
Zhong-Ping Ou

SummaryThe asymmetric bisazo derivatives of Arsenazo and Phosphonazo have been widely used as chromogenic reagents in spectrophotometric determination of thorium, uranium, rare earth elements and other heavy metals. They exhibit advantages over the symmetric reagents such as Arsenazo m and Chlorophosphonazo III both in sensitivity and selectivity. The following is a brief introduction and short review on these reagents concerning their structures, analytical characteristics, synthesis, purification and application. 182 references mainly published in the past decade are presented.

2020 ◽  
Author(s):  
Elena Di Stefano ◽  
Giovanni Baccolo ◽  
Paolo Gabrielli ◽  
Aja Ellis ◽  
Barbara Delmonte ◽  
...  

<p>Deposition of dust on the Antarctic continent is controlled by many factors, such as the primary supply of dust particles from the continents [1], the long range transport, the hydrological cycle and the snow accumulation rate [2, 3]. Thus, the study of mineral dust in ice cores gives the possibility to reconstruct past climatic and environmental conditions.</p><p>Generally, when an ice core sample is melted, soluble elements dissolve in water, while insoluble elements remain in the solid phase. Other elements, such as iron, calcium, potassium and sulfur, typically partition between the soluble and the insoluble fractions. However recent studies have shown how the dust record may be chemically and physically altered in deep ice cores [4, 5], posing a challenge in the interpretation of the climatic signal that may lie within such samples. In particular, relative abundance of specific elements was shown to be different when comparing shallow and deep dust samples, suggesting that post depositional processes are taking place.</p><p>In this study we present a comparison between samples belonging to the Talos Dome ice core analyzed through two different techniques: instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). While the former is used to investigate only the insoluble fraction of dust, as it can only be applied to solid samples, the latter is used to assess the elemental composition of both the total and the soluble fraction of dust. We determined 45 elements through ICP-MS and 39 through INAA, with a good overlapping of the elements between the two techniques. Besides the determination of major elements, the high sensibility of both techniques also permitted the determination of trace elements. Among these, rare earth elements (REE) are of particular importance as they have been widely used as a geochemical tracer of aeolian dust sources [6]. We here present depth profiles for each analysed element, covering discrete portions of the entire ice core.</p><p> </p><p>Bibliography</p><p>[1] Petit, Jean-Robert, et al. "Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica." Nature 399.6735 (1999): 429-436.</p><p>[2] Lambert, Fabrice, et al. "Dust-climate couplings over the past 800,000 years from the EPICA Dome C ice core." Nature 452.7187 (2008): 616.</p><p>[3] Wegner, Anna, et al. "The role of seasonality of mineral dust concentration and size on glacial/interglacial dust changes in the EPICA Dronning Maud Land ice core." Journal of Geophysical Research: Atmospheres 120.19 (2015): 9916-9931.</p><p>[4] Baccolo, Giovanni, et al. “The contribution of synchrotron light for the characterization of atmospheric mineral dust in deep ice cores: Preliminary results from the Talos Dome ice core (East Antarctica).” Condensed Matter 3, no. 3 (2018): 25.</p><p>[5] De Angelis, Martine, et al. “Micro-investigation of EPICA Dome C bottom ice: Evidence of long term in situ processes involving acid-salt interactions, mineral dust, and organic matter.” Quaternary Science Reviews 78 (2013): 248-265.</p><p>[6] Gabrielli, Paolo, et al. “A major glacial-interglacial change in aeolian dust composition inferred from Rare Earth Elements in Antarctic ice.” Quaternary Science Reviews 29, no. 1-2 (2010): 265-273.</p><p><strong> </strong></p>


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