Yellow Zinc Research Articles

Examination of pigments on Thai manuscripts: the first identification of copper citrate

AbstractSamples from Thai manuscripts dated to the 18th to 20th century were analyzed by Raman spectroscopy and Fourier‐transform infrared spectroscopy (FTIR) to determine the pigments used. This suggested a change in palette from the 18th to 20th century, with use of imported pigments in the later manuscripts. In the 18th century, the main green used was an organic copper salt, which was replaced by emerald green and mixtures of Prussian blue with gamboge, chrome yellow and zinc yellow (zinc potassium chromate). Chrome yellow was used in addition to gamboge in one later 19th century manuscript. Similarly, indigo in the 18th century manuscripts was replaced by Prussian blue and then synthetic ultramarine in the 19th century manuscripts.Lead white was the main white pigment in all but one manuscript, which contained huntite, a magnesium calcium carbonate. Huntite also occurred in mixtures with other pigments in two other manuscripts. In all the works studied, red lead, vermilion and red earth were used for red, orange and pink shades and red earth in brown areas.The organic copper salt used in the 18th century gave good FTIR spectra but could not initially be matched with any published compound. X‐ray diffraction (XRD) suggested this was a copper citrate phase, and examination of the literature showed that the FTIR spectra matched those published for a hydrated copper citrate. Raman spectra were obtained from this organic copper salt, which showed close agreement with those obtained from synthetic copper citrate. Copper citrate has not been identified previously as an artist's material, although its use has been postulated on the basis of historical texts. Minor copper formate and/or copper chloride were also identified by XRD and scanning electron microscopy (SEM) in some green samples containing copper citrate. Copyright © 2008 John Wiley & Sons, Ltd.

Pigment study by Raman microscopy of 23 paintings by the Portuguese artist Henrique Pousão (1859–1884)

AbstractTwenty‐three paintings by Henrique Pousão—a 19th century Portuguese painter—belonging to the collection of Museu Nacional Soares dos Reis, Porto, Portugal, were analysed by Raman microscopy. The fine focus of a 100× objective allowed the visualisation and individual identification of small grains. As a result, thirty‐seven compounds, namely, anatase, barium white, basic lead sulfate, brochantite, cadmium red, cadmium yellow, calcium carbonate, carbon‐based black, celadonite, chrome green, chrome orange, chrome yellow, cobalt blue, cochineal lake, copper sulfide, emerald green, iron(III) oxyhydroxide, iron(III) oxide, kaolinite, lead antimonate yellow, lead carbonate, lead white, lead sulfate, madder lake, malachite, Prussian blue, quartz, realgar/pararealgar, red lead, rutile, Scheele's green, strontium yellow, ultramarine blue, vermilion, viridian, zinc white and zinc yellow, were identified. Not all these compounds are pigments; some are extenders, others trace components and others probably products of reactions between pigments. Special attention was given to the Raman characterisation of celadonite, chrome orange, basic lead sulfate and lead antimonate yellow. Complementary techniques were used to confirm the identities of certain pigments and to characterise reference samples. Pousão, whose work has not previously been studied spectroscopically, was found to have used a remarkably wide range of pigments over his painting periods, without showing significant preference for any particular set of pigments. Copyright © 2007 John Wiley & Sons, Ltd.

Chromatic behavior of inorganic pigments in restoration mortars (nonhydraulic lime, hydraulic lime, gypsum, and portland cement). A comparative study

AbstractSpectral diffuse reflectance was used to make a comparative study of the chromatic behavior (stability, coloring power and effects of time, thermal gradients, and high energy ultraviolet radiation) of the inorganic pigments ultramarine blue, green earth, molybdenum orange, zinc yellow, chrome yellow, chrome green, ochre, and natural sienna when mixed with the binders: nonhydraulic lime, hydraulic lime, Portland cement, and gypsum. The results show acute interference of the limes and the Portland cement, and, to a lesser extent, of the gypsum on the initial colors of ultramarine blue, molybdenum orange, and chrome yellow. The other pigments studied showed good stability in the four binders. Time, thermal gradients, and high energy ultraviolet radiation caused no appreciable color changes, except in the case of chrome yellow, which presented slight changes over time. © 2006 Wiley Periodicals, Inc. Col Res Appl, 32, 65–70, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20289

Rejuvenating the color palette of Georges Seurat's A Sunday on La Grande Jatte—1884: A simulation

AbstractGeorges Seurat first employed his divisionist painting technique, commonly called pointillism, on A Sunday on La Grande Jatte—1884 beginning in October 1885. Painting with pigments representing colors seen in the visible spectrum that were minimally mixed on the palette and using divided brushstrokes, he aimed to impart “luminosity” to the surface and to explore color theories that were being developed and disseminated at that time, such as simultaneous contrast, in his unique interpretation. In addition to the natural ageing of the painting materials causing an overall darkening of the painting, pigment analysis has disclosed that the brushwork containing zinc yellow has darkened significantly: yellow, green–yellow, and orange brushstrokes have become ochre‐like, olive–green, and reddish–brown, respectively. By performing spectral reflectance measurements in situ on darkened areas of the painting and on paint‐outs of comparable unaltered colors, using Kubelka–Munk turbid media theory, imaging the painting with color‐managed digital photography, and image editing with Adobe Photoshop, a digital version of the original, more luminous appearance of La Grande Jatte was simulated. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 278–293, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20223

Accelerated and EIS tests for anticorrosive paints pigmented with ecological pigments

Substitution of zinc chromate or zinc yellow, traditionally used as anticorrosive pigment, for other phosphate‐based pigments that are not hazardous to health and have the same anticorrosive behaviour or even better, is studied in this paper. Four alkyd paints were specially prepared; two of them contained calcium acid phosphate or micronised zinc phosphate as anticorrosive pigments respectively. A paint containing zinc chromate was used as reference and a paint without anticorrosive pigments was used as a blank, in which the other ingredients were increased proportionally to attain the desired PVC relationship. The corrosion behaviour of low carbon steel panels coated with these paints in a 3 per cent NaCl solution was assessed by electrochemical impedance spectroscopy (EIS). In addition, other painted panels were evaluated by salt spray and humidity chamber tests. Results of all tests showed that the paint with calcium acid phosphate and especially that with micronised zinc phosphate exhibited better behaviour than paint with zinc chromate. Analysis of impedance parameters (ionic resistance and capacitance of the paint film) against immersion time allowed the paints to be ranked in the same order as that obtained with salt spray and humidity chamber tests.

The Zinc Violet and its Colonization by Arbuscular Mycorrhizal Fungi

Summary Among the plants growing on several heavy metal soils, the zinc violets (the yellow Viola calaminaria (DC.) Lej. s. str. of the Aachen/Liege area and the blue Viola guestphalica Nauenburg of Blankenrode/Paderborn) were consistently colonized by arbuscular mycorrhizal (AM) fungi. The degree of AM-colonization apparently correlated with the heavy metal content in soils as indicated by the composition of the plant community. Among diverse violets examined from various non-polluted areas, Viola lutea (DC.) Lej. and some other alpine violets showed high mycorrhizal colonizations of the roots. A specific Glomus Br1 isolate was obtained from the roots of the yellow zinc violet ( V. calaminaria s. str.) of the Breinigerberg area near Aachen. RFLP-analysis indicated the uniformity of this isolate. Incubation with Glomus Br1 allowed plants like maize, barley, alfalfa and zinc violets to grow until flower and seed formation in two different heavy metal soils supplemented with nutrient solutions in greenhouse experiments. Controls (sterilized heavy metal soils not inoculated with Glomus Br1 or yellow lupins as non-mycorrhizal plants) did not grow. The Glomus Br1 isolate from the zinc violet more efficiently supported growth of maize or alfalfa in heavy metal soils than a commonly used Glomus intraradices Schenck and Smith isolate. The potential applications of these findings are discussed.

Effects of nitrilotriacetic acid on the induction of gene mutations and sister-chromatid exchanges by insoluble chromium compounds

The influence of nitrilotriacetic acid trisodium salt (NTA) on the mutagenic and clastogenic activity of several water-insoluble or poorly soluble chromium compounds was determined by means of the Salmonella/microsome assay (plate test on TA100 strain) and the sister-chromatid exchange (SCE) test in mammalian cell cultures (CHO line). NTA in itself did not induce gene mutations nor did it increase the frequency of SCE. Cr(VI) compounds (Pb, Ba, Zn, Sr and Ca chromates) and an industrial Cr(VI) pigment, chromium orange (containing PbCrO 4·PbO), were inactive or scarcely active mutagens in the Salmonella/microsome test when dissolved in water, but they were increasingly mutagenic when solubilized by 0.5 N NaOH or NTA (10 or 100 mg/ml). Also, the mutagenic activity of Cr(VI), contaminating an industrial Cr(III) pigment (chromite), was slightly enhanced by NTA. Mutagenicity of chromates was correlated with the amounts of Cr(VI) solubilized by NTA or alkali, as determined by the colorimetric reaction with diphenylcarbazide and atomic absorption spectrophotometry, and was decreased by incubation with microsomes, due to reduction of Cr(VI) to the genetically inactive Cr(III) form. In the SCE assay, the insoluble or poorly soluble Ba, Zn, Sr and Ca chromates and the insoluble Cr(VI) pigments zinc yellow (containing ZnCrO 4·Zn(OH 2)), chromium yellow and molybdenum orange (both containing PbCrO 4) were directly clastogenic due to cellular endocytosis taking place in prolonged treatments, and NTA significantly increased their chromosome-damaging activity.

Cytotoxic and clastogenic effects of soluble and insoluble compounds containing hexavalent and trivalent chromium

Cr(III) and Cr(VI) compounds of varying solubilities have been tested in vitro for their ability to inhibit cell growth and nucleic acid and protein syntheses in BHK cells, to induce alterations in the mitotic cycle in HEp cells, and to increase the frequency of chromosomal aberrations and sister chromatid exchanges (SCE) in CHO cells. All Cr(VI) compounds, and particularly those containing soluble Cr(VI), such as potassium dichromate and zinc yellow, differentially inhibit macromolecular syntheses in BKH cells, that of DNA being always the most affected. Among Cr(III) compounds, which generally have very low cytotoxicity, chromite is particularly active, and inhibits cell growth and DNA synthesis even more than the poorly soluble Cr(VI) compounds. Preincubation in growth medium, with or without metabolizing cell cultures, solubilizes considerable amounts of Cr(VI) from zinc yellow and chromite, but significant amounts are also obtained from the most insoluble Cr(VI) pigments. When BHK cells are treated with such preincubated solutions, reduction of soluble Cr(VI) to Cr(III) by cell metabolites is seen with all Cr(VI) compounds, accompanied by decreased cytotoxicity. The same differences between Cr(VI) and Cr(III) compounds apply to the cytotoxic effects on mitosis of HEp cells and the clastogenic effects on CHO cells. The activity of chromite, the only Cr(III) pigment capable of significantly increasing the frequency of SCE, is due to contamination with soluble Cr(VI). In contrast to the very low cytotoxicity of Cr(III), much higher chromium levels are detected in the cells incubated with soluble Cr(III) than with the same concentrations of soluble Cr(VI). 50% and 75% of chromium accumulated in the cells during treatments with Cr(VI) and Cr(III) respectively remains firmly bound to the cells, even when they are incubated for up to 48 h in normal growth medium. Chromium accumulated in the cells after treatment with Cr(III) is most probably bound to the cell membrane, whereas some of the Cr(VI) is transported through the cell membrane and reduced in the cell nucleus. The results of the present investigation are in agreement with those obtained with the same Cr(VI) and Cr(III) compounds in mutagenicity assays in bacteria and carcinogenicity tests in rodents. A re-evaluation of the mechanisms of chromium carcinogenisis is proposed.

Histochemical observations on the pancreatic islets in normal and obese-hyperglycemic mice

In the islets of Langerhans in mice with the American variety of the obese-hyperglycemic syndrome (AO) and their thin litter mates (AN) the following observations were made: 1. In cryostat sections of fresh pancreatic tissue from AN-mice, both more centrally situated islet cells with yellowish white granules, and peripherally situated cells with brighter silver white granules were found with dark field microscopy. While the central cells were considerably degranulated in the AO-mice, the peripheral cells were also well filled with granules in these animals. The technique described offers, especially in the AO-mice, better possibilities of differentiation of the islet cells than with the granule staining methods of fixed pancreatic material, which are now generally used. 2. After intravenous injection of dithizone, abundant orange yellow zinc dithizonate granules were found in all islet cells with dark field microscopy of cryostat sections from fresh pancreatic tissue of AN-mice. By dissolving out these granules, the zinc content could be related to the different types of islet cells. It was possible in this way to show that the zinc in the islets of the AO-mice was mainly situated in the peripheral cells, containing the silver white granulation typical of untreated animals in dark field. The occurrence of a lower zinc content in the centrally situated islet cells in the AO-mice was also evident from the so-called “sulphide-silver method”. 3. A positive islet reaction to both acid and alkaline phosphatases was obtained in the AN-mice. The alkaline phosphatase activity was high in the peripheral parts of the islets of AN-mice, but much lower in the AO-mice. While the majority of islet capillaries were strongly positive as regards alkaline phosphatases in the AN-mice, in the AO-mice they were for the most part completely negative. 4. In spite of the existence of a prolonged hyperglycemia, no storage of glycogen could be demonstrated in the islets of the AO-mice. With fluorescence microscopy, the occurrence of masked lipids in the islets was observed in the AN-mice, and to an even higher degree in the AO-mice. On the other hand the sudanophilic reaction was negative throughout. The raised functional activity in the islet B-cells of the AO-mice was reflected in an enlargement and fragmentation of the Golgi apparatus.

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The reduction of ferricyanides and a sensitive test for the detection of hydrogen peroxide

Yellow zinc ferricyanide is reduced by heating to white zinc ferrocyanide by hydrogen peroxide in the presence of zinc sulphate and sodium, acetate. Copper ferricyanide, however, is reduced to brown copper ferrocyanide at room temperature, by means of hydrogen peroxide in the presence of copper sulphate and sodium acetate. The latter reaction can be applied for the detection of extremely small quantities of hydrogen peroxide both in a test tube (2.5 γ in 1 ml) and as a spot test (0.5 to 1 γ).

The Low-temperature Yellow Zinc Silicate Phosphor.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Low-temperature Yellow Zinc Silicate Phosphor.Herman C. FroelichCite this: J. Phys. Chem. 1943, 47, 9, 669–677Publication Date (Print):September 1, 1943Publication History Published online1 May 2002Published inissue 1 September 1943https://doi.org/10.1021/j150432a006RIGHTS & PERMISSIONSArticle Views149Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (562 KB) Get e-Alerts