Color differentiation usefulness

Note The dipping solution can also be used as spray solution. Since the chromatogram zones slowly fade in the air it is recommended that the chromatograms be covered with a glass plate for long-term storage. Color differentiation is possible with purine derivatives [6, 8]. Diprophylline is not colored [6]. 

Note Tertiary amines and quaternary ammonium compounds yield stronger colors than primary amines [25]. The dipping solution can also be used as spray solution [44]. Other reagent compositions have also been reported in the literature (1, 3, 6, 12, 13, 15, 18, 21, 23, 41] In some cases the reagents have been made up in acetone [38, 39], methanol [14] or ethanol [37] and/or acidified with hydrochloric acid [3, 33, 37-40]. The concentrations of hexachloroplatinic(IV) acid have been in the range of 0.05 -0.4 those of potassium iodide between 0.5 and 24spray solution containing 2% potassium iodide and 0.23170 hexachloroplatinic(IV) acid hexahydrate in N-hydro-chloric acid is reported to yield the best coloration results with respect to detection sensitivity and color differentiation in the detection of morphine, codeine, quinine, methadone and cocaine [46]. Acidic reagent solutions have been recommended for benzodiazepines [10, 11]. Sulfones do not react [39]. 

The use of color-differentiation is favored whereas the use of color coding is controversial because of the limited number of colors, the prevalence of color blindness in the general population, and inappropriate reliance on color in lieu of reading the label. 

Figure 2.9. Biosynthetic gene clusters for NEO-family AGAs. Functionally related groups of genes are differentiated by the color code given below (A) color code used in all genetic maps for 2DOS and 2DOS-related AGAs (B) color code for pathway-specific functions in the NEO family. See color plates.

Do not use color to differentiate areas of the figure. Use black only for a color, and use gray tones to differentiate areas of the figure. 

Both the GET and POST methods accept KEGG identifiers as input and colors in hexadecimal code (hex code) format for fore- and background color. The usage of hex code for colors allows use of color gradients for mapping of differential gene expression or different metabolite concentrations. 

Mercury can exist in two ionic forms The mercury(I) ion which is foxmd as the dimer Hg2 +, and the mercury(II) ion Hg +. Mercury is unique because it is the only metallic element that is a liquid at room temperature. The chemistry of mercury(I) and mercury(II) is quite different and this allows differentiation using the two tests described. Mercury lies above copper in the electrochemical series, which is used in test (a) as an identification of mercury(ll) and mercury(II). Mercury(II) forms an insoluble oxide of a characteristic color and this is used in test (b). 

Several spray reagents permit a certain color differentiation between selected vitamin E derivatives. Thus P- and y-tocopherol can be distinguished using such spray reagents as phosphomolybdic... 

Most hydrocarbon resins are composed of a mixture of monomers and are rather difficult to hiUy characterize on a molecular level. The characteristics of resins are typically defined by physical properties such as softening point, color, molecular weight, melt viscosity, and solubiHty parameter. These properties predict performance characteristics and are essential in designing resins for specific appHcations. Actual characterization techniques used to define the broad molecular properties of hydrocarbon resins are Fourier transform infrared spectroscopy (ftir), nuclear magnetic resonance spectroscopy (nmr), and differential scanning calorimetry (dsc). 

The initial uses of colorants in plastics were as extenders and additives. Carbon black and titanium dioxide were and are stiU used as fillers (qv) because of their low cost. Almost from plastics inception the limitation of black and white did not offer sufficient color choices for end users looking to differentiate their products. The increase in aesthetic requirements along with different performance requirements and resin compatibiUties led to a great expansion in the number of different chemical classes of colorants and forms in which these colorants are available in today s market. 

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