Chapter 4 – Tests for the Elements, their Ions and Compounds
01 Jan 1972-pp 94-524
About: The article was published on 1972-01-01. It has received 6 citations till now.
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TL;DR: Since the mid-19th century, various pest eradication techniques have been employed on the anthropology collections at the National Museum of Natural History, Smithsonian Institution as mentioned in this paper, and these techniques are reviewed, and pesticide and fumigant use by early collectors and later collections management staff is documented.
Abstract: Since the mid-19th century, various pest eradication techniques have been employed on the anthropology collections at the National Museum of Natural History, Smithsonian Institution. These techniques are reviewed, and pesticide and fumigant use by early collectors and later collections management staff is documented. Also chronicled are the ways in which the choice of chemicals has changed over the years and the decisions that led to those changes. The effects of pest eradication techniques on the collections are discussed, and the author's findings are offered as the basis for further research.
63 citations
TL;DR: In this paper, the main features, molecular structures and physical and chemical properties of these carbon types, so far as they are relevant to pigment studies, are reviewed in outline and some better-known pigments based on carbon are summarized, with an indication of which form or forms of carbon each contains.
Abstract: A primary classification of carbons is into crystalline and non-crystalline forms. The only crystalline carbon encountered as a pigment is graphite; a secondary classification for non-crystalline forms is into flame carbons (formed in the gas phase), cokes (formed in a liquid or plastic phase), chars (formed entirely in the solid phase) and natural forms such as coal. The main features, molecular structures and physical and chemical properties of these carbon types, so far as they are relevant to pigment studies, are reviewed in outline. Some better-known pigments based on carbon are summarized, with an indication of which form or forms of carbon each contains. X-ray diffraction patterns for graphites, and for examples of the non-crystalline types, are described and discussed. Particle morphology of various carbons and pigments, as elucidated from scanning electron micrographs, is described in some detail, and notes are added on the use of optical microscopy in studying these materials.
48 citations
TL;DR: In this paper, the Freer collection of Japanese paintings of the twelfth to the sixteenth centuries has been determined, and basic lead carbonate (lead white) was found in 12 out of 13 Chinese paintings and in all three Korean paintings.
Abstract: Japanese paintings of the twelfth to the sixteenth centuries in the collection of the Freer Gallery of Art has been determined. In 12 out of 13 Chinese paintings, and in all three Korean paintings, basic lead carbonate (lead white) was found. Of the 29 Japanese paintings, six had basic lead carbonate, 20 had basic lead chloride (which occurred as two different compounds), and two carried both of these species. One Chinese painting had lead sulphate and one Japanese painting lead phosphate. Historical evidence suggests that two forms of 'lead white' were known and distinguished during the eighth century in Japan; the possible connection between this and the present findings on Japanese paintings is discussed.
16 citations
TL;DR: The outlook and likely impact of these tests on the expansion of scientific investigation and legacy and technical details of selected spot tests used in solving crime are described.
Abstract: Chemical spot tests are one of the oldest and simplest presumptive methods of analytical chemistry. They are an integral part of the schematic analysis of different types of substances in various pure and applied scientific disciplines including forensic science. The role of spot tests has remained eternal utility in different branches of forensic science to analyze various types of physical or trace evidences. Forensic experts need to have an absolute understanding of the foundation and technicality behind complex reactions of customary spot tests. Forensic science literature dwells in the diversity of spot tests but an informative and comprehensive compendium of such prose remains occasional and limited in general. Keeping in view the ample history and legacy of spot test, the current review was constructed from a core of historical literature to recapitulate trending applications, chemistry, and limitations of notable "Griess test", "Luminol test", "Kastle-Meyer test", "Phenolphthalein test", "Ninhydrin test", and "Spy dust" in forensic science. The aim of this review article was to describe the outlook and likely impact of these tests on the expansion of scientific investigation. The anticipated output of this review is supposed to impart compatible knowledge in the attentive readers interested in understanding legacy and technical details of selected spot tests used in solving crime.
7 citations
TL;DR: In this article, the corrosion products on a silver dragon suspected to have been treated with cyanide revealed both silver cyanide and chalconatronite, which can be formed on silver objects cleaned or replated using a cyanide solution.
Abstract: Analysis of the corrosion products on a silver dragon suspected to have been treated with cyanide revealed both silver cyanide and chalconatronite. It appears that both of these corrosion products can be formed on silver objects cleaned or replated using a cyanide solution. These corrosion products darken with exposure to light; therefore, they may be mistaken for silver sulfide. In order to determine how to remove the highly poisonous cyanide corrosion product, numerous tests were run. Using a carefully timed procedure the silver cyanide was removed with an aqueous solution of 20% sodium thiosulfate. The chalconatronite was removed mechanically.
5 citations
References
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TL;DR: In this article, a semi-micro analysis for the major elements in clay minerals, based mainly on improvements to conventional colorimetric methods, is presented for the semi micro analysis of clay minerals.
Abstract: A scheme is presented for the semi-micro analysis for the major elements in clay minerals, based mainly on improvements to conventional colorimetric methods. Silica and alumina are determined after fusing a 50-rag sample with sodium hydroxide. Titanium, total iron, calcium, magnesium, phosphorus and manganese are determined colorimetrically on a hydrofluoric-sulphuric acid digest of a 50-mg sample; sodium and potassium are determined flame photometrically on the same digest. Ferrous iron is determined separately. Additional methods for the determination of total water, total sulphur and fluorine are indicated.
30 citations
TL;DR: Uranium (VI) can be extracted as a complex with rhodamine B into a benzeneetherhexone solvent from a benzoate buffered solution, leading to a molar absorptivity of 102700 mmol-1 cm2 at 555 nm, the highest yet reported for a uranium complex as mentioned in this paper.
30 citations
TL;DR: In this paper, a method for simultaneous spectrophotometric determination of cobalt, nickel and copper has been developed, and the results of the application of this procedure to synthetic samples and to several National Bureau of Standards Samples are given.
30 citations
TL;DR: The blue color of zirconium-pyrocatechol violet complex was used in a very sensitive colorimetric method for ZIRconium in dilute sulfuric acid solutions.
Abstract: S>The blue color of zirconium-pyrocatechol violet complex is used in a very sensitive colorimetric method for zirconium in dilute sulfuric acid solutions. Molar absorbance index of complex is 32,600 at 650 m mu . It conforms to Reer's law up to 2 gamma zirconium per ml. Aluminum, titanium, and vamadium interfere seriously. (auth)
30 citations
TL;DR: In this article, the limitations of these methods for fluorine compounds and conditions allowing their reliable use for milligram and microgram samples of compounds containing up to about 60% of fluorine are described.
30 citations