Substances interfering with

N. Masque R. M. Marce and E. Boirull, Chemical removal of humic substances interfering with the on-line solid-phase exti action-liquid chi omatographic determination of polar water pollutants , Chromatographia 4 231-236 (1998). 

In those cases where there exists a possibility of organic substances interfering with the estimation of hydrogen peroxide by treatment with a solution of potassium permanganate or potassium iodide, the use of a standard solution of stannous chloride has been proposed the reaction follows the course... 

It should be noted that the particular effect produced in an experimental animal study does not generally have a bearing on determinations of relevance. If an agent causes tail defects in the offspring of treated mice, for example, this effect is not automatically considered irrelevant to humans simply because humans do not have tails. Instead, the assumption is that the mouse study demonstrated that the chemical substance interfered with vertebral development and therefore has relevance for vertebral or other features of human development. 

Substances interfering with this assay include buffers which are amino acid or peptide in nature, such as Tris and Good s buffers, because they give positive color formation. The Cu ions are also susceptible to reduction. This can be detected in practice by appearance of a red precipitate in the reaction mixture. 

An important consideration in the choice of enzyme is also that the samples to be measured should not contain substances that could interfere with the activity of the enzyme or its measurement. This applies primarily but not exclusively to assays in which the enzyme-labeled compound is incubated together with the sample. Some obvious examples include the need to avoid samples containing EDTA if the enzyme utilized requires metals for activity. Similarly, oxidoreductases cannot be used when the samples contain some commonly used preservatives. Endogenous enzyme inhibitors or other substances interfering with the activity or stability of the enzymes may also be present in the samples to be assayed. 

Enzyme studies are still necessary, but one cannot exclude the role that new factors may play here. In this connection we (M21) have described the presence in human urine of substances interfering with pyridoxal-5-phosphate-dependent enzymes. 

It has a low mammal toxicity. The acute oral lDjq is 35IS mg/kg for rats. Fenpropimorph causes no unwanted side-effects in cereals. The first results indicate that the active substance interfers with the sterol synthesis. 

Heat energy produced by the friction of striking the match provides the activation energy for this combustion process. 8.11 If the enzyme catalyzed a process needed to sustain life, the substance interfering with that enzyme would be classified as a poison. 

If the enzyme catalyzed a process needed to sustain life, the substance interfering with that enzyme would be classified as a poison. 

Common natural inhibitors of ribonucleotide reduction are the negative allosteric effectors dATP, dTTP, and to a lesser extent, dGTP. Several less defined substances interfering with dQOxyribonucleotide formation in vitro have been observed in extracts of yeast, wheat, and rodent cells . Some of these inhibitory fractions had spectral or chemical properties resembling nucleotides while others were tentatively identified as protein Celltilar as well as synthetic RNA efficiently inhibits ribonuc-... 

Realization of a final receptor preparation depends on the starting material and the specific RRA. In general, preparative procedures are designed to concentrate receptors in a crude manner and remove endogenous substances interfering with the... 

The most common interfering substance, especially with alcohols of low mole cular weight, is water this may result in an inaccurate interpretation of the test if applied alone. Most of the water may usually be removed by shaking with a little anhydrous calcium sulphate,. though dry ethers (and also the saturated aliphatic and the simple aromatic hydrocarbons) do not react with sodium, many other classes of organic compounds do. Thus ... 

Plant material water contents range from high (>90%, e.g. vegetables) to low (< 10%, e.g. straw, herbs, tea, hops, etc.). Thus the ratio between the analytes (residues) and the organic matter potentially interfering with the analysis is very different for, e.g., cucumber and camomile tea. Other ingredients in plant materials such as acids, oil, sugars, starch or substances typically for the taste and effect of plant materials may have properties similar to those of the analytes and thus interfere in or influence the cleanup procedures. 

The quaternary ammonium salt 73, thenium closylate, is an anthelmintic agent. Many substances of this general type are effective by interfering with nervous conduction, and thereby muscle tone, of intestinal worms. This allows their expulsion, not... 

Attention was first directed toward the dextrans about the middle of the last century as these slimes were at times a serious problem in the wine and beet sugar industries. In the latter, jelly-like masses blocked the filters and interfered with the refining processes by retarding crystallization. Dextran, at various times, was regarded as a protoplasmic constituent of the beet cell,22 a product of sucrose fermentation, and as cellulose produced by fermentation.22 The empirical formula, (CeHioOs)n, for dextran was obtained2422 at an early date (about 1875) on hydrolysis, the substance was found to yield only D-glucose.1422-24 A tribenzoate and a triacetate of dextran were prepared by Daumichen.24... 

Blood Agents Substances that injure a person by interfering with cell respiration by dealing with the exchange of oxygen and carbon dioxide between blood and tissues. 

---