Acetone sensitivity test

Not all air-inhibited surfaces can be detected by the Barcol hardness tests. It is recommended that the acetone sensitivity test should also be used, where appropriate. This involves application of a small amount of acetone to the resin surface. The wetted surface is then rubbed lightly with the finger until the acetone has evaporated. If the surface softens or becomes tacky, the resin has not fully cured. 

The flow-cell design was introduced by Stieg and Nieman [166] in 1978 for analytical uses of CL. Burguera and Townshend [167] used the CL emission produced by the oxidation of alkylamines by benzoyl peroxide to determine aliphatic secondary and tertiary amines in chloroform or acetone. They tested various coiled flow cells for monitoring the CL emission produced by the cobalt-catalyzed oxidation of luminol by hydrogen peroxide and the fluorescein-sensitized oxidation of sulfide by sodium hypochlorite [168], Rule and Seitz [169] reported one of the first applications of flow injection analysis (FTA) in the CL detection of peroxide with luminol in the presence of a copper ion catalyst. They... 

Other sensitive tests for cyanide may he used, e.g. the pink colour produced with a mixture of chloramlne-T, barbiturio acid solution and y-benzyl pyridine in acetone. 

Note Results of impact sensitivity tests show that acetone triperoxide is one of the most sensitive explosives known... 

Methyl alcohol of very high purity can be obtained by fractional distillation using a column of 1-3 metres effective length and then refluxing with aluminium amalgam. It is then refluxed under a column packed with dehydrated copper sulphate, to remove ammonia. A sensitive test for acetone and formaldehyde is the addition of cone, mercuric cyanide solution, in 6N-sodium hydroxide. A white precipitate indicates ketone if it darkens on standing aldehyde is also present. (J. C. S., 127, 2552.)... 

Kutschke132 made a sensitive test for 0l8018 formation by photo-oxidizing acetone labeled with O18 in the presence of light oxygen. No 018018 was observed and the formation of acetone-16 was confirmed. 

A more sensitive test for hydroxyproline (0.1 /xg/5 cm ) is performed by first dipping the plate in 0.2% isatin in acetone, drying, and then spraying with Ehrlich s reagent (Section 4.7.6). Only hydroxyproline among 200 amino compounds gives a purple-red spot. 

Initially, LMW inhalation drugs can be screened for their ability to sensitize the immune system. A contact sensitization model, the local lymph node assay (LENA), has been validated for the identification of agents that cause skin sensitization (Kimber et al, 1991). In this model, the test article is prepared in a vehicle, such as olive oil/acetone, and applied to both ears of mice for three consecutive days, and on the sixth day, proliferation in draining lymph node is determined (Gerberick et al, 2000). Test articles that produce a stimulation index greater than three times vehicle control are considered positive contact sensitizers. To date, most if not all LMW respiratory sensitizers tested... 

For multi-analyte and/or multi-matrix methods, it is not possible to validate a method for all combinations of analyte, concentration and type of sample matrix that may be encountered in subsequent use of the method. On the other hand, the standards EN1528 andEN 12393 consist of a range of old multi-residue methods. The working principles of these methods are accepted not only in Europe, but all over the world. Most often these methods are based on extractions with acetone, acetonitrile, ethyl acetate or n-hexane. Subsequent cleanup steps are based on solvent partition steps and size exclusion or adsorption chromatography on Florisil, silica gel or alumina. Each solvent and each cleanup step has been successfully applied to hundreds of pesticides and tested in countless method validation studies. The selectivity and sensitivity of GC combined with electron capture, nitrogen-phosphorus, flame photometric or mass spectrometric detectors for a large number of pesticides are acceptable. 

Accdg to Marshall (Ref 2), expls at high temps are considerably more sensitive conversely their sensitiveness is reduced on cooling them. In experiments conducted in France by Kling Florentin (Ref 1), expls, as well as their, detonators were cooled to temp —80°C by means of solid carbon dioxide and acetone, or to about —190° with liquid nitrogen. Table E2 lists the results of the tests... 

Following props(Ref 6) of dimeric acetone peroxide were deed at PicArsn action with match flame — a slight puff hrisance by sand test — 30.1 g sand crushed when 0.4 g of peroxide was initiated with 0.2 g MF, vs 48.0 g sand crushed by 0.4 g TNT impact sensitivity, BurMinesApp with 2 kg wt —... 

Dipentaerythrite hexanitrate116 is procured in the pure state by the fractional crystallization from moist acetone of the crude PETN which precipitates when the nitration mixture is drowned in water, white crystals, m.p. 72°. The crystals have a specific gravity of 1.630 at 15°, after being fused and solidified 1.613 at 15°. The substance is less sensitive to friction, less sensitive to the mechanical shock of the drop test, and less sensitive to temperature than PETN, but it is less stable and decomposes much more rapidly at 100°. 

Another weak point of many allelopathic research studies reported in the literature is the lack of proper statistical analysis. Probably the two most critical errors are the lack of proper controls and insufficient replication. Appropriate controls need to be included even when a minimal amount of a solvent [e.g., dimethyl sulfoxide (DMSO), acetone, etc.] is used to solublilize a compound or for extraction of the test plant material. In this situation, it is also helpful to include positive controls (known compounds at similar concentrations) for comparison to the unknown or suspected allelochemicals. As discussed earlier, it is also useful to include various species so that a range of sensitivity to the test material can be observed. For example, a bioassay using seed germination might include lettuce seed, generally a sensitive species, and other species which might vary in response to the allelochemical(s) or extract. Such selection can demonstrate plant... 

Formation of indigo test The test depends upon the conversion of acetone, formed by the dry distillation of acetates (see reaction 10), into indigo. No other fatty acids give this test, but the sensitivity is reduced in their presence. 

The state of tin in Pt/Sn/alumina catalysts was investigated bv Li and Shia (25) via Mossbauer spectroscopy (i/9Sn enriched isotopes) and XPS. The former technique indicated the presence of Sn+, Sn+2 and Sn, in proportions that depended on the method of preparation, but in all cases the Sn+4 component dominated. These conclusions were confirmed by the XPS experiments. Additional TPR tests on the reduced catalyst and on samples exposed to air showed that reoxidation of Pt/Sn/alumina reduced preparations was rather slow, confirming our EXAFS observations. The presence of zero valent tin in similar preparations, using the acetone complexation procedure, was recently confirmed by Li, Stencel and Davis (12) in an extended XPS investigation. For reduced samples, with a Pt Sn ratio 1 5, these authors estimated that approximately 68% of the tin was in the metallic state. However, they observed that exposure of the sample to air for 10 minutes entirely eliminated the XPS detectable Sn°. Their data also indicated that upon reduction, chlorine migrated from the surface to the alumina. Thus, XPS which measures surface composition indicates a higher sensitivity to oxidation than was demonstrated by our EXAFS experiments, which is a bulk diagnostic. 

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