Differences in X‐ray absorption due to cadmium treatment in Saponaria officinalis leaves

Abstract

A method for detecting cadmium uptake in leaves of Saponaria officinalis doped with a solution of cadmium acetate is described. The technique based on the exposure of dried leaves to X-rays of a wavelength close to that of the metal K-edge could be useful for phytoremediation studies as it could reveal the bioaccumulation in plants due to the treatment either in vivo or in vitro with heavy metals. X-ray microradiography measurements are in agreement with those from peroxidase enzyme assay utilized to follow the oxidative damage induced by heavy metals. At present, as we will see in this report, microradiography has still poorer sensitivity in comparison with enzyme assay, but it has the advantage of being faster, not destructive, and usable even at very high doping levels, where the enzyme assay technique results are fully saturated. Further analysis of the optical density values could lead to a quantitative measurement of the heavy metal in the sample. Thus, the technology developed in this article could be useful for tracing the intake in phytoremediation studies.

Monitoring of the heavy‐metal hyperaccumulation in vegetal tissues by X‐ray radiography and by femto‐second laser induced breakdown spectroscopy

“…The grayscale levels of the scanned (CanonScan FS4000US) images were converted into optical density values using both the RAR 2492 film response curve (using Kodak standard film) in the investigated spectral range and the scanner's calibration curve. More detailed description on the detection part of the experimental set-up can be found in (Reale et al, 2004).…”

“…At present, this method does not provide us with precise quantitative results. The poor sensitivity is due to the wide bandwidth of our radiation source (Reale et al, 2004). This bandwidth does not permit a precise selection of a given metal, because the radiation emitted by the source can be absorbed by other elements (S, Mg etc.)…”

“…We mainly intend to compare the different characteristics and proper use of selected techniques, instead of giving a precise detection limit for each utilized method and sample investigated. The first two experimental techniques are based on X-ray microradiography investigations, which make use both of soft X-rays generated either by plasma laser source (*1 keV) (Reale et al, 2004;Tillman et al, 1996) or synchrotron radiation of the SYRMEP beamline of Elettra Synchrotron Trieste for X-ray dual-energy microradiography at rather high photon energies (8.5-35 keV) (Kaiser et al, 2005). The third one is the LIBS technique, which has proved to be a powerful, low-cost, and relatively simple method (Assion et al, 2003;Samek et al, 1999).…”

Microradiography as a tool to detect heavy metal uptake in plants for phytoremediation applications

“…Contact microradiography is a straightforward application of laser-plasma sources to biology (Reale et al, 2004). In the experiments presented here, the use of a wide spectral distribution of the X-rays has significantly limited the sensitivity on recognizing the chemical nature in the different leaves' structures.…”

Qualitative detection of Mg content in a leaf of Hedera helix by using X‐ray radiation from a laser plasma source

“…(Albertano et al, 1997a,b;Bollanti et al, 1998;Cotton et al,1992Cotton et al, , 1995Fletcher et al, 1992). Hence, using different chemical elements as the target, makes it possible to observe in the X-ray detector where these metals have accumulated within the sample (Kaiser et al, 2005(Kaiser et al, , 2007Reale et al, 2004Reale et al, , 2006.…”