Filter paper impregnation

Filter paper impregnated with dicarbonyl(benz-2,l,3-thiadiazole)rhodium chloride gives characteristic colorations with the aminophenol isomers after fixation and can be used as an indicator paper (99). 

Procedure Purslane seeds were collected from crop fields near Naples. Five hundred seeds were sown in 10 Petri dishes (0 =90 mm), containing 5 layers of Whatman filter paper impregnated with 7 ml of water (control) or 7 ml rue infusion/chromatographic fractions or isolated compounds as per treatment. Thereafter, daily 3 ml water was added to each Petri plate. Germination conditions were 30 1°C with a continuous light of 25 4,E/m2/... 

Accelerated Aging of Filter Papers Impregnated with Model Compounds ... 

The usefulness of this ligand in the construction of Ca2+-sensors has been confirmed. The selectivity behavior of a liquid membrane, which consists of a filter paper impregnated with a 20% solution of the ligand in p-nitroethylbenzene (117), was determined by means of EMF-measure-ments conducted on the cell ... 

Phosphate must be applied as fertilizer to the soil. Ideally it is added in quantities sufficient to guarantee optimal yields, but not in excess in order to avoid P transportation into other compartments of the ecosystem. The amount added should be based on an accurate estimation of the plant-available fraction of P already present in a soil.This is an old and difficult task and a large number of extraction methods have been used since intensive land use was practised. Recently methods have been worked out in which a strip of filter paper impregnated with an Fe oxide (2-line ferri-hydrite) is dipped into a soil suspension and the amount of P adsorbed by the paper is taken as being plant-available (Sissingh,1988 Van der Zee et ah, 1987 Sharpley, 1993 Sharpley et ah,1994 Kuo and Jellum, 1994 Myers et ah 1997). Anion and cation resins extracted more P from four heavily fertilized soils than from goethite (Delgado Torrent, 2000). Other oxyanions adsorbed by soil Fe oxides are silicate, arsenate, chromate, selenite ( ) and sulphate. Adsorption of sulphate led to a release of OH ions and was substantially lowered once the Fe oxides were selectively removed (Fig.16.17). 

Papel explosivo, in Span). Under these names are known absorbent (such as filter) papers impregnated by solns of various substances and then dried. They served as basis of several propellants and expls... 

The Gutzeit Test.3—This test is as accurate as the Marsh test and the apparatus necessary is comparatively simple. It consists in allowing the arsine to react with strips or discs of dry filter paper impregnated with silver nitrate or, in the more recent modifications of the method, mercuric chloride or bromide. 

The spot-test technique is as follows. Mix on a spot plate a drop of the alkaline test solution with a drop of a 1 per cent solution of sodium nitroprusside. A violet colour appears. Alternatively, filter paper impregnated with an ammonia-cal (2m) solution of sodium nitroprusside may be employed. 

Fluorescein test Free bromine converts the yellow dyestuff fluorescein(I) into the red tetrabromofluorescein or eosin(II). Filter paper impregnated with fluorescein solution is therefore a valuable reagent for bromine vapour since the paper acquires a red colour. 

Method. Mix the sample with a little manganese dioxide and heat to dull redness whilst holding a piece of filter paper, impregnated with the reagent, in the vapours issuing from the tube. Indications. The yellow colour of the filter... 

As the filter paper is incapable of sampling the volatile radioactivities such as iodine, activated carbon is used for the sampling of such radioactivities. Filter paper impregnated with activated carbon and a cartridge filled with layers of activated carbon granules are available. 

Filter paper impregnated activated carbon Gaseous (volatile material) " 1,3 S, 2 Hg Gross P-and y-ray measurement y-ray spectrum analysis... 

Perhaps the most convenient and presently accepted method of determining bacterial MICs, however, is the E (Epsilometer)-test. Basically this is performed in a similar manner to the disc test except that nylon strips that have a linear gradient of antimicrobial lyophilized on one side are used instead of the filter-paper impregnated antimicrobial discs. On the other side of the nylon strip are a series... 

Traces of hydrogen fluoride are conveniently separated by microdiffusion [6-9]. The sample is placed in a polypropylene container, which is then closed. The HF distils isothermally from cone. HCIO4 over about 20 hours and is absorbed in dilute NaOH solution, or in filter paper impregnated with NaOH. The micro-diffusion of HF has been performed in the presence of hexamethyldisiloxane, which yields the volatile trimethylfluorosilane with HF in a H2SO4 medium [10,11]. 

Other procedures using, for example, exposure on filter paper impregnated with the toxicant for earthworms clearly presents an ideal situation that does not appear to be environmentally realistic. Comparison of different routes of exposure to the toxicant has, however, been made with Eisenia andrei (Belfroid et al. 1993), and the acute toxicity was given as lethal body burden (LBB) after exposure to 1,2,3-trichloro- and pentachlorobenzene. Exposure was carried out in water, in soil via food, and on filter paper, and when LBBs were normalized to lipid content the values for pentachlorobenzene were comparable, although the value for 1,2,3-trichlo-robenzene for exposure on filter paper was higher than for the other routes of exposure. 

In addition to the foregoing methods, other highly specialized techniques have also been used occasionally to investigate the cellular structure of free convection. For example, Mysels (M5) has employed the color change produced in a filter paper impregnated with cobaltous chloride and held just above the surface of evaporating water, to detect differences in the evaporation rate from different areas of the surface. Earlier, Dauzere (Dl) had... 

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