Optimum decomposition

Instrumental Interfaces. The ideal Ic/ms interface should place no compromises on either the Ic or the ms. Decomposition or loss of analyte should be avoided and efficient transfer provides for optimum sensitivity. 

Aqueous solutions of vitamin > 2 at pH 4.0 to 7.0 show no decomposition during extended storage at 25°C. For optimum stability at elevated temperatures, solutions should be adjusted to pH 4.0 to 4.5. Aqueous solutions in this pH range maybe autoclaved for 20 min at 120°C without significant decomp o sition. 

A common deposition reaction combines the metal chloride with a hydrocarbon, such as butane, at an optimum deposition temperature of 1000°C.9 1 Other hydrocarbons can also be used. Another useful reaction is the decomposition of the chromium di cumene Cr[(C6H5)C3H7]2 in atemperature range of 300-550°C and at pressures of 0.5-50 Torr.0 1... 

The rapid inactivation of human lysosomal / -D-galactosidase is noteworthy, as the reaction had to be carried out at 2 pH units above its pH optimum (pH 4.0) in order to minimize the spontaneous decomposition of the inhibitor. Similar conditions had to be employed for ) -D-xylosidase from Penicil-lium wortmamii (optimum at pH 3.5), which was studied at pH 7.0. 

Enzymes are nature s catalysts. For the moment it is sufficient to consider an enzyme as a large protein, the structure of which results in a very shape-specific active site (Fig. 1.3). Flaving shapes that are optimally suited to guide reactant molecules (usually referred to as substrates) in the optimum configuration for reaction, enzymes are highly specific and efficient catalysts. For example, the enzyme catalase catalyzes the decomposition of hydrogen peroxide into water and oxygen... 

The layer of titanium and ruthenium oxides usually is applied to a titanium substrate pyrolytically, by thermal decomposition (at a temperature of about 450°C) of an aqueous or alcoholic solution of the chlorides or of complex compounds of titanium and rathenium. The optimum layer composition corresponds to 25 to 30 atom % of ruthenium. The layer contains some quantity of chlorine its composition can be written as Ruq 2sTio 750(2- c)Cl r At this deposition temperature and Ru-Ti ratio, the layer is a poorly ordered solid solution of the dioxides of ruthenium and titanium. Chlorine is completely eliminated from the layer when this is formed at higher temperatures (up to 800°C), and the solid solution decomposes into two independent phases of titanium dioxide and ruthenium dioxide no longer exhibiting the unique catalytic properties. 

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