PubMed · 13023286
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W S DAVIS, J N SMITH. 1952. Lead poisoning.. https://pubmed.ncbi.nlm.nih.gov/13023286/
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In this study, the potential genotoxic effects and phytoremediation capacity of Ludwigia repens J.R. Forst. were evaluated under lead (Pb) stress in contaminated aquatic environments. To achieve this, clonal L. repens plants were used to investigate their ability to remove Pb from freshwater systems and the experimental setup was established in controlled aquarium conditions. The plants were exposed to 0, 10, 25, 50 and 100 micromolar (μM) concentrations of Pb(NO3)2 in a 0.2% Hoagland nutrient solution for a period of ten days. Experimental results showed that Pb accumulated in both stems and leaves of L. repens. Although Pb levels did not meet hyperaccumulator criteria, the bioaccumulation index (BAI), bioconcentration factor (BCF) and translocation factor (TF) values revealed that the plant was capable of accumulating noteworthy amounts of Pb. In parallel, band profile analysis revealed new band appearances only with the UBC 812 primer, while no band loss or new band formation was detected with the other primers (UBC 808, UBC 826, UBC 833 and UBC 834). Instead, only changes in band intensities were observed, indicating a low polymorphism rate and a high level of genomic template stability (GTS). The findings also indicate that L. repens exhibits notable tolerance to Pb stress, as supported by high BAI, BCF and TF values in the absence of visible phytotoxic symptoms. Additionally, the consistent and progressive decline in mineral nutrient levels across Pb treatments, together with the moderate decline in total chlorophyll content, further supports the existence of a coordinated physiological adjustment, potentially reflecting a tolerance mechanism aimed at maintaining ionic balance under heavy metal stress. Moreover, low polymorphism rates and high genomic template stability (GTS) values derived from molecular analyses suggest that this species may serve as a genetically stable and physiologically resilient aquatic plant. These combined traits highlight its potential to contribute effectively to phytoremediation applications, particularly when co-cultivated with established Pb hyperaccumulator species.
The combination of metrological weighing, the measurement of isotope amount ratios by a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS) and the use of high-purity reference materials are the cornerstones to achieve improved results for the amount content of lead in wine by the reversed isotope dilution technique. Isotope dilution mass spectrometry (IDMS) and reversed IDMS have the potential to be a so-called primary method, with which close comparability and well-stated combined measurement uncertainties can be obtained. This work describes the detailed uncertainty budget determination using the ISO-GUM approach. The traces of lead in wine were separated from the matrix by ion exchange chromatography after HNO(3)/H(2)O(2) microwave digestion. The thallium isotope amount ratio ( n((205)Tl)/ n((203)Tl)) was used to correct for mass discrimination using an exponential model approach. The corrected lead isotope amount ratio n((206)Pb)/ n((208)Pb) for the isotopic standard SRM 981 measured in our laboratory was compared with ratio values considered to be the least uncertain. The result has been compared in a so-called pilot study "lead in wine" organised by the CCQM (Comité Consultatif pour la Quantité de Matière, BIPM, Paris; the highest measurement authority for analytical chemical measurements). The result for the lead amount content k(Pb) and the corresponding expanded uncertainty U given by our laboratory was:k(Pb)=1.329 x 10-10mol g-1 (amount content of lead in wine)U[k(Pb)]=1.0 x 10-12mol g-1 (expanded uncertainty U=kxuc, k=2)The uncertainty of the main influence parameter of the combined measurement uncertainty was determined to be the isotope amount ratio R(206,B) of the blend between the enriched spike and the sample.
Mosaic gold, tin (IV) sulphide, is a yellow pigment which was known in antiquity but whose use was superseded by other more easily obtainable yellow pigments by the Renaissance. The identification of mosaic gold residues in a burnished golden mirror decoration on a XIIIth Century Spanish polychrome statue is important in that the first reference to the use of mosaic gold in the European literature dates from the XIVth Century, although the use of this material in China had been recorded some time before. In this paper, Raman spectroscopy, XRD and SEM are used in the analysis of the conditions required for the formation of golden mirrors using tin (IV) sulphide in admixture with dilead (II) lead (IV) tetroxide and mercury (II) sulphide. From these results, it is proposed that the major reactions are the reduction of Sn(IV) to Sn(0) with the accompanying oxidation of lead (II) oxide to lead (IV) oxide and the formation of lead (0) and lead (II) sulphide. From these results it was possible to explain the process of creation of the golden mirror from mosaic gold in the XIIIth Century.