Blue-Print Paper

This paper also can be used in a parallel way to diazo-type paper. A detailed report has been made on its use for making paper chromatogram copies in UV light [239]. 

The paper is relatively insensitive to daylight. Long exposure times are needed even in UV light, so that a wide range of exposure is available. Development is carried out by moistening with water. 

So little experience has been accumulated about the use of these two types of paper for documentation of chromatograms, that then-value in this field cannot be estimated. 

Positive Copies and Photographs with Procedures Based on Diffusion of Silver Salts 

In this procedure, the silver halide of the negative emulsion which has not been modified by the action of light, is allowed to diffuse into the positive emulsion through a thin layer of the more or less viscous developer its silver content is then precipitated to yield a positive picture [473]. A wet after-treatment is not necessary. 

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Used in reprographic processes, particularly the ozalid blue-print paper processes. 

Tin(lV) chloride is a mordant for dying fabrics a stabihzer for perfume in soap used in weighting silk in ceramic coatings in manufacturing blue print papers and to produce fuchsin. Also, tin(IV) chloride is used in preparing many organotin compounds. 

Direct copying on Ozalid or Ultrarapid blue print paper has also been employed for documentation [25—27]. For this purpose the chromatograms are laid layer-... 

Ferric ammonium citrate (C6H607Fe.C6H60r(NH4)2H), is used in making blue-print paper (242). A strong solution of neutral ammonium citrate is used in the analysis of fertilizers in the separation of the different forms of phosphates which the fertilizers contain. 

Diphenylamine in aqueous Triton X-100 medium was applied to determine Ag in photographic print paper [3]. The catalytic effect of Ag on the peroxodisulfate oxidation of Brilliant Cresyl Blue with 1,10-phenanthroline as activator makes the basis of the determination of Ag in river water [4]. 

After the blue-print is ready the actual question paper is set. Some of the commonly used tests in chemistry are fill-ins, true-false, multiple-choice, short-answer or essay-type etc. 

In 1972 I wrote a paper [76] to summarize my overall conclusion, a forecast and blue print for computational quantum chemistry use a combination of ab initio computations, when feasible, and density functional SCF techniques, by that time already successfully... 

The reaction of free metals with phosphomolybdic acid (see page 87) can be used for rapidly detecting free metal in zinc oxide and other oxides. This test can also be applied to metallic dusts on decorative wrappings, printed paper, etc. The basis of the test is the formation of the highly colored molybdenum blue by the action of phosphomolybdic acid with free metals and alloys. 

Procedure. A small filter paper is impregnated with nitric acid-molybdate solution. The mounted section or the polished area of the rock is warmed (the section should not be heated to the point that the Canada balsam becomes mobile) and pressed at once on the moist paper and left for 1 or 2 minutes. The paper is laid (with the surface of contact upward) on a second paper soaked in benzidine solution, so that the solution rises through the upper paper. The latter is then held over ammonia and an exact blue print is obtained of the crystals of apatite in the section. If the contours of the section have been drawn on the paper, the exact location of the crystals is revealed. Even the smallest crystals of apatite, of whose apatitic nature there may be some doubt, may be identified in this way, thus amplifying or even replacing optical examination. 

Dessauer was aware of a very stable triphenylmethane leucodye tris(/7-A,A-diethylamino-o-tolyl)methane, which had been considered for a commercial product for the important spirit duplicating market. It was found by Cescon and Dessauer that the leucodye salt could be easily oxidized to give a deep blue color in solution, and a deep blue print when the exposure was carried out on filter paper that had been immersed in a solution of these components. 

Spkit Blue [2152-64-9] Cl Solvent Blue 23 (Cl 42760), is one of the few dyes sulfonated as the leuco base. The degree of sulfonation depends on the conditions. Monosulfonated derivatives, commonly referred to as alkaU blues, eg. Cl Acid Blue 119 [1324-76-17, are used as thek barium or calcium salts in printing inks. Disulfonated compounds, eg. Cl Acid Blue 48 [1324-77-2] are employed as thek sodium or ammonium salts for blueing paper, whereas the trisulfonic derivatives or ink blues, eg. Cl Acid Blue 93 [28983-56A] are used in writing inks (qv). 

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