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
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935 citations
TL;DR: A sensitive and simple technique was worked out for the colorimetric determination of inorganic phosphate, on the basis of the principle that Malachite Green at a lower pH forms a complex with phosphomolybdate with a marked shift of the absorption maximum.
773 citations
TL;DR: In this article, a mixture of sulfanilic acid, N-(1-naphthyl)-ethylenediamine dihydrochloride, and acetic acid was used to detect nitrogen dioxide.
Abstract: The determination of nitrogen dioxide in the atmosphere has heretofore been hampered by difficulties in sample absorption and lack of specificity. A new specific reagent has been developed and demonstrated to absorb efficiently in a midget fritted bubbler at levels below 1 ppM. The reagent is a mixture of sulfanilic acid, N-(1-naphthyl)-ethylenediamine dihydrochloride, and acetic acid. A stable direct color is produced with a sensitivity of a few parts per billion for a 10-minute sample at 0.4 liter per minute. Ozone in five-fold excess and other gases in tenfold excess produce only slight interfering effects; these may be reduced further by means which are described. 25 references, 1 figure, 3 tables.
663 citations
TL;DR: In this article, the AutoAnalyzer is used for determining nitrate and nitrite in fresh and sea water and in soil extracts with the help of a modified manual procedure by Wood, Armstrong and Richards, which consists in reduction of nitrate with copperised cadmium and, with the nitrite thus produced, diazotisation of sulphanilamide, the product being coupled with N-1-naphthylethylenediamine to form a highly coloured azo dye, which is measured at 520 nm.
Abstract: Automatic methods for determining nitrate and nitrite in fresh and sea water and in soil extracts with the AutoAnalyzer are described, together with details of the analytical systems. The methods are based on a modification of the manual procedure by Wood, Armstrong and Richards, which consists in reduction of nitrate with copperised cadmium and, with the nitrite thus produced, diazotisation of sulphanilamide, the product being coupled with N-1-naphthylethylenediamine to form a highly coloured azo dye, which is measured at 520 nm. The methods are capable of analysing twenty samples per hour.
551 citations