Reagents residues

Evaluation of chromatograms la 133ff Evaluation, peak area or height la 31,33,40 -, optical trains la 30, 39 Evipan la 339,343 Excitation to fluorescence la 10,12,20,37 Explosion resulting from reagent residues la 82,253,261,315,365 Explosives lb 49,244,407-409 Exposure to vapors la 86... 

Reagent Residued Labeled and its Functional Significance° Pumps Labeled... 

Reagent Residual activity (%) Relative amounts of label (%) ... 

Paper and thin-layer chromatography are two such approaches. The techniques are simple and require inexpensive equipment. If one chooses the proper solvents, adsorbents, and chromogenic reagents, residues can be isolated on a sheet of chromatographic paper or a thin layer of adsorbent. The type of residue can then be determined by comparison with reference standards. 

High-pressure liquid chromatography (HPLC) allows the separation of soluble materials into component parts based on the partitioning of the materials between a mobile (solvent) and stationary (column packing) phase. With proper choice of solvent and column packing, separation of many types of materials is possible. HPLC has been used successfully to determine reagent residues on fabrics treated with durable press finishes as well as detennining formaldehyde levels in aqueous solutions obtained by the AATCC Test Method 112. ... 

Beck K R, Pasad D M, Vail S L and Xiang Z, Reagent residues on N-methylol-pyrrolidone treated cotton . Journal of Applied Polymer Science. 1984,29,3579-3585. 

CAUTION CAUTION This is a very vigorous reaction. Use caution. Leave all HOOD equipment in the hood until it is obvious the residual reagent has reacted with the moist air (white fumes subside). Make sure that only glass surfaces are in contact with the reagent residues. 

A correlation of the number of specific protein groups modified with the number of reagent residues introduced into the protein is another desirable featmre of any study of tiie type covered by this review. In the case of oxidation or reduction reactions in which no reagent residues are attached to the protein the stoichiometry of the reaction provides equivalent information. 

M. are preferentially used in nonfood applications (- starch industrial applications). Their use in food and pharmaceutical production is strictly limited by governmental and international regulations with respect to kind and amount of substituents as well as reagent residues. In the EU (1998) the shipment of m. exceeded 16% of the entire production (7.5 X 10 mt) of starch and starch products. 

In contrast to - cellulose derivatives, which are modified to a greater extent to make them water-soluble, low - DS are sufficient in most of the s. to have the wanted effect on their functional properties. Derivatization reactions are mostly performed in heterogeneous aqueous phase at alkaline pH, keeping the s. in the granular state. After completing the reactions, the starch granules are washed free from reagent residues and other solubles, dewatered and dried. 

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