Metal Casse

Metal instabilities ( casse ) are relatively rare today but when encountered, the metals involved are generally copper or iron. Copper casse is present as an initially white and later a reddish-brown precipitate in bottled or other wines stored under low-oxygen conditions. An iron instability may be present as either ferric phosphate ( white casse) or ferric tannate ( blue casse). Even though a ferric phosphate instability is described as white casse, it may assume various shades of a blue amorphous precipi- 

Preliminary acidification of a suspect wine sample using 10% v/v HCl is useful in separation of metal-containing complexes from complexes of protein (Section 17.5.1) and phenolics (Section 17.5.2). If the haze solubilizes (step 5), the problem is probably a metal casse, and the wine can be further characterized for being either copper or iron (Section 17.5.4.2). If the haze remains (step 5), the instability is probably due to protein or complexes of protein, protein-phenolics, or phenolics-phenolics. Finally, the test described in Section 17.5.4.3 can be used to determine if a suspect wine may have the potential develop a casse after bottling. 

Place 0.5g K4Fe(CN)g 3H20 into a lOOmL volumetric flask and add 95 mL distilled water. When completely dissolved, bring to 100 mL final volume with distilled water. 

Transfer 15mL of the suspect wine to a 18 x 150 mm test tube. 

If the haze dissipates, the problem is probably a metal casse. 

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Finally, in view of its acidity, wine is likely to corrode metal winemaking equipment, thus dissolving some toxic cations and others responsible for metallic casse. For example, copper, nickel and even lead may be extracted from bronze equipment (pumps, vat taps, hose connections, etc.). This property may also be exploited when wine... 

Crystalline Crystal-like Fibrous Amorphous Potassium bitartrate, calcium tartrate, or calcium oxalate Cork fragments or diatomaceous earth Cellulose, case lint, or asbestos Protein, phenolic, polysaccharide (glucan, pectin, or starch) or metallic casse... 

When microscopically examined, this group of precipitates lack defined shape and generally assumes a color reflective of the wine. Precipitates in this category include protein and phenolics (and complexes of the two), polysaccharides (glucans, pectin, and starch), and metal casses (copper and iron). 

Water samples (drinking water, rain, sea, river or waste water and others) have been characterized by ICP-MS with multi-element capability in respect to metal impurities (such as Ag, Al, As, Ba, Be, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Na, Sb, Se, Mg, Mn, Mo, Ni, Pb, Tl, Th, U, V and Zn) in many laboratories in routine mode with detection limits at the low ng I 1 range using ICP-QMS, and below by means of ICP-SFMS. Drinking water samples are controlled in respect of the European legislation (Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption). For quality control of analytical data, certified standard reference materials e.g. drinking water standard (40CFR 141.51), river water reference material SLRS-4 or CASS-2 certified reference sea-water material and others are employed. 

Cass GR, McRae GJ. 1986. Emissions and air quality relationships for atmospheric trace metals. In Nriagu JO, Davidson Cl, eds. Toxic metals in the atmosphere. New York, NY John Wiley and Sons, Inc., 145-171. 

Bernd Wrackmeyer received his Diploma in Chemistry from the University of Munich in 1971 and his Ph.D. from the same University with Heinrich Noth in 1973. He performed postdoctoral studies at John Cass College of Science and Technology in London with William McFarlane in 1974 and moved back to the University of Munich in 1975, where he finished his habilitation in 1979. He became a Heisenberg-Fellow in 1983 and moved to the University of Bayreuth in 1986. His work focuses on the application of multinuclear magnetic resonance spectroscopy (NMR), on the chemistry of organoboranes, carboranes, Group 14 metal chemistry and on metal amides. 

Lavoisier, Antoine-Laurent. Opuscules physiques et chimiques (Paris Durand Neveu, 1774). Translation Essays Physical and Chemical (London printed for Joseph Johnson, 1776) second edition (London Frank Cass Co., 1970). Lavoisier, Antoine-Laurent. Memoire sur la nature du principe qui se combine avec les Metaux pendant leur calcination, C qui en augmente le poids. Observations 5,1775, 429-433 translated as A Memoire on the Nature of the Principle which is combined with metals during their Calciantion, and occasions an Increase in their Weight. 407-419 in Essays published in a revised form in Memoires, 1775 (pub. 1778), 520-526 Oeuvres II, 122-128. 

As discussed previously, growth and chemical reactions of nanoparticles lead to changes in their compositions. Thus the inferences in composition described above should hold only for fresh nanoparticles correlations should weaken with atmospheric aging of the particles. It would be desirable to compare these expectations against actual field measurements of particle compositions. However, quantitative measurements of the chemical composition of ambient ultrafme particles are available only for the larger members of this class (Dp 50-100 nm). Available data, from urban areas in Southern California, indicate that organic compounds represent approximately half of the ultrafme particle mass. The remaining mass is contributed by trace metal oxides, elemental carbon, sulfate, nitrate, ammonium, sodium, and chloride (Cass et al. 2000). 

Cass GR and McRae GJ (1983) Source-receptor reconciliation of routine air monitoring data for trace metals an emission inventory assisted approach. Environ SdTechnol 17 129-139. 

Iron and copper are present in small qnantities, bnt they are significant causes of instability (ferric casse and copper casse), so they are described in separate sections (Sections 4.6 and 4.7). Heavy metals, mainly lead, even in trace amounts, also affect toxicity and deserve a separate description (Section 4.8). 

Wine always contains a few mg/1 of iron. A small percentage comes from grapes (2 to 5 mg/1). The rest comes from soil on the grapes, metal winemaking, handling and transportation equipment, as well as improperly coated concrete vats. The general use of stainless steel has considerably reduced the risk of excess iron and, consequently, of ferric casse. 

Metallic precipitation (ferric casse and copper casse)... 

Bailey N, Middleton K W, Casse A and Gaillard R Improved productivity through metal powder additions to submerged arc welds . CEC Report EUR-11 180, 1987. Pub L-2985, Luxembourg, CEC. 

Wiedmer, S. K., Cassely, A., Hong, M. F, Novotny, M. V., and Riekkola, M. L. Electrophoretic studies of polygalacturonate oligomers and their interactions with metal ions. Electrophoresis 21, 3212-3219... 

The Pb imprinted resins were then applied to chemical analysis [26]. Experiments were carried out to determine and compare percent recoveries of Pb from the seawater samples by using different ion exchange resins, such as Chelex-100, Duolite GT-73, a proprietary NASA resin, and the Pb imprinted ion exchange resin. The percent recoveries from the Pb imprinted resin were greater than 95% over a broad range of pH. The Pb imprinted ion exchange resin did not suffer from interferences from other metal ions in seawater matrix. The Pb imprinted resin gave superior performance when used for separation and preconcentration prior to analysis by either AAS or spectrophotometry. The utility of the Pb imprinted resin was demonstrated by analysis of a standard reference material. Coastal reference seawater (CASS-3). The resin extract was of suificient purity to be analyzed by spectrophotometry with the nonspecific indicator dithizone. 

Accuracy. Analytical accuracy may be derived by anal3rsing an appropriate standard reference material, if available. The results obtained by the procedure described here for the seawater standard reference materials NASS-1 and CASS-2 (see Section 12.1.6) were always in good agreement with the certified values. The deviations never exceeded 20%. The TXRF results of trace metal intercalibration in estuarine water, organized by the International Council for the Exploration of the Sea (ICES, 1988) have also been accepted as true values in the considered concentration range. 

Raymond K.N., Cass M.E., Evans S.L. Metal sequestering agents in bioinorganic chemistry enterobactin mediated iron transport in E. coli and biomimetic applications. Pure and Applied Chemistry, 59 771-778 (1987). 

Fig. 5.11. Preconcentration and elution of trace metals in seawater (reference material (CASS-1). Concentrations it jected are 0.094, 0.23, and 0.018 /ig 1 for Cr, Ni, and Co. Legend lists concentrations in original sample. The sample was injected at time zero, and the eluent was changed to remove the analyte complexes at the time indicated by the arrow. Reproduced from Anal. Chem. [50] with permission of American Chemical Society.

Taubert, A. Palivan, C. Casse, O. Gozzo, F. Schmitt, B.(2007) Ionic liquid-crystal precursors (ILCPs) for CuCl platelets The origin of the exothermic peak in the DSC curves. /. Phys. Chem. C, 111,11, 4077-4082,1932-7447 Taubert, A. Arbell, I. Mecke, A. Graf, P. (2006). Photoreduction of a crystalline Au(III) complex a solid-state approach to metallic nanostructures. Gold Bull. 39, 4, 205-211, 0017-1557... 

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