Colorings column

Arrows denote p strands. Colored columns correspond to the five almost Invariant residues described in the text and shown in Figure 13.14. 

The best presentation will have considered text font, color, columns, relationship of text to diagrams, single-sided printing, etc. 

This approach was used for the determination of OTC, TC, and CTC in milk samples. The centrifuged raw milk was mixed with succinate buffer (pH 4.0) to precipitate proteins. The clear supernatant was loaded directly on an MCAC column (1.5-ml Chelating Sepharose Fast-Flow) activated by passage of both water and 10 mM copper(II) sulphate solution. The blue-colored column was washed with both water and MeOH, and TCs were eluted with McIlvaine/EDTA/NaCl buffer. The extract was injected directly into the chromatographic system (25). 

Figure 8.18 shows the two nonreactive profiles (CS i and CS2) originating from the product specifications and are connected by profiles of the internal RCSs. The two nonreactive profiles are thick black lines, while the reactive profiles that the column follows are represented by thick colored lines, coordinated with the colored column structure in Figure 8.18. All profile continuations are represented by thinner lines. It is interesting to note that the nonreactive CSs actually intersect one another in this design (note the profile intersections). The intersection of nonreactive profiles in a reactive column like this is however senseless, because this design absolutely requires the reactive zone. Thus, in this case, the nonreactive profiles that terminate the column at either end need to be joined up by all the reactive profiles.

Figure 1.1. Schematic representation of the conventional process for the synthesis of methyl acetate (left) and the highly task-integrated RD unit (right). Legend ROl reactor SOI splitter S02 extractive distillation SOS solvent recovery S04 MeOH recovery SOS extractor S06 azeotropic column S07,S09 flash columns SOS color column VOl decanter...

Collins reagent 16, 320 suppl. 23 Colman s. Gabriel Colored compounds s. Compounds, colored Column reactor 18, 853 suppl. 23... 

Saybolt color NF M 07-003 ASTM D 156 standard Height of liquid column for equality with colored glass... 

LC can be used for both volatile and nonvolatile substances, but GC can handle only volatile substances. Chromatography was originally a method for separating and displaying mixtures of colored substances on a colorless column of solid material. The word chromatography is derived from chroma (color) and graph (writing). 

The cmde phthaUc anhydride is subjected to a thermal pretreatment or heat soak at atmospheric pressure to complete dehydration of traces of phthahc acid and to convert color bodies to higher boiling compounds that can be removed by distillation. The addition of chemicals during the heat soak promotes condensation reactions and shortens the time required for them. Use of potassium hydroxide and sodium nitrate, carbonate, bicarbonate, sulfate, or borate has been patented (30). Purification is by continuous vacuum distillation, as shown by two columns in Figure 1. The most troublesome impurity is phthahde (l(3)-isobenzofuranone), which is stmcturaHy similar to phthahc anhydride. Reactor and recovery conditions must be carefully chosen to minimize phthahde contamination (31). Phthahde [87-41-2] is also reduced by adding potassium hydroxide during the heat soak (30). 

The most widely appHed colorimetric assay for amino acids rehes upon ninhydrin-mediated color formation (129). Fluorescamine [38183-12-9] and (9-phthalaldehyde [643-79-8] are popular as fluorescence reagents. The latter reagent, ia conjunction with 2-mercaptoethanol, is most often used ia post-column detection of amino acids separated by conventional automated amino acid analysis. More recently, determiaation by capillary 2one electrophoresis has been developed and it is possible to determine attomole quantities of amino acids (130). 

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