Ethylenediaminetetraacetate, suppressive

In order to determine S(IV) in rain water, it is necessary to prevent the oxidation of S(IV) between sampling and analysis. The suppressive effect on the oxidation of S(IV) was investigated by the addition of EDTA (Ethylenediaminetetraacetate) or TEA (Triethanolamine) as masking reagents for FeJ+ and Mn. Table III shows the suppressive effect of EDTA or TEA at various pH values. The suppressive effect was not observed between pH 3 and 5, because neither EDTA nor TEA chelate with Fe3+ and Mnz+ at these pH values. EDTA and TEA were found to be very effective for the suppression of the oxidation of S(IV) in solutions having neutral and basic pH values. 

Gomisin C has an inhibitory effect on the respiratory burst of rat neutrophils in vitro [243], The mechanism of action may be mediated partly by the suppression of NADPH oxidase and partly by the decrease in cytosolic Ca2+ released from an agonist-sensitive intracellular store. In fact, gomisin C attenuated the activity of TPA-activated neutrophil particulate NADPH oxidase in a concentration-dependent manner and reduced the increase in cytosolic free Ca2+ in neutrophils stimulated by fMLP in presence or absence of ethylenediaminetetraacetic acid (EDTA). In addition, this study suggests that the gomisin C mechanism is not mediated by changes in cellular cAMP or in inositol phosphates, or by scavenging... 

The nse of a high ionic strength acidic extraction solvent is required to suppress metabolic activity upon disrnption of the cell and to precipitate proteins. A metal chelator snch as ethylenediaminetetraacetic acid (EDTA) is also usually required. The use of metaphosphoric acid is the best way to extract and stabilize L-ascorbic acid, as suggested by various authors [72,78,80,81]. For this reason, the samples were extracted with 3% metaphosphoric acid-8% acetic acid-1 mM EDTA solution, which is known to limit L-ascorbic acid degradation to less than 5% [82]. 

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