Interfering factors

The instrument prevents automatically from interfering factors. 

Use of the K p for precipitation information is often complicated by a number of interfering factors including complexation of metallic ions, high ionic strength solutions, and high solids contents. This principle is applicable solely to ionic compounds, i.e., primarily inorganic compounds. 

The method of color development may be nonspecific and therefore the reaction may be affected by many interfering factors commonly found in serum such as turbidity, hemoglobin and bilirubin. 

The instrument response (T) changes dramatically with little or no change in analyte value (X). In this example additional clarification is required to define the relationship between the analyte value and the spectroscopic/chemical data for the sample, as interfering factors other than analyte concentration are affecting the instrument response. 

In general, in animal research, it is well to be cautious, whether bufotenin or 5-methoxylated tryptamines or other substances postulated to be useful hallucinogenic tools are used and to be aware of the status of knowledge of their effects in humans, let alone on a characteristic battery of effects in animals. In rat, for example, 5-methoxytryptamine (20 mg/kg) appeared to markedly increase 5-HT metabolism as judged by 5-HIAA, although interfering factors in measurement were not ruled out (29). 

Table 2.6 Ultimate temperatures at a wall temperature of 300 K temperature of Tq= 300 K (i.e. when the cryopanel is exposed to the thermal radiation of the wall) sufficiently low ultimate pressures can be attained. Due to a number of interfering factors like desorption from the wall and leaks, the theoretical ultimate pressures are not attained in practice.

When the rates of deton are plotted against densities, approx straight lines can be obtained when the interfering factor (such as impurity, confinement, differences in granulation, etc) are considere d. A straight line... 

Two independent replicate solutions of the preparation being examined at the dilution with which the test for interfering factors was completed. Use water BET to make two independent dilution series of four tubes containing the preparation being examined at concentrations of 1, 1/2, 1/4, and 1/8 relative to the dilution with which the test for interfering factors was completed. 

Two independent replicate solutions of the preparation being examined at the dilution with which the test for interfering factors was completed and endotoxin standard BRP at a concentration of 2X. 

Equilibrium constant determination for alkoxysilane hydrolysis. Triethyl-silanol was selected as a model compound for determination of the equilibrium constant for equation (1), since under neutral conditions the condensation to disiloxane was observed to take place only over an extended period of time (i.e. years), eliminating equilibria (2) and (3) as interfering factors. 

Statistical properties, including sources of errors in the measurement process, control of interfering factors, calibration of response signals, modeling of complex multivariate signals, etc. 

Jurkiewicz S (1977) Problem of the effect of interfering factors in the quantitative determination of lignin compounds in aqueous solutions Przegl Papier 33(1) 30-35, Abstr Bull Inst Pap Chem 48 1245... 

The techniques of Raman and IR spectroscopy are generally considered complementary in the gas and solid phases because some of the species under study may reveal themselves in only one of the techniques. Nevertheless, it must be stressed that Raman scattering is not affected by an aqueous medium, whereas the strong absorption in the infrared shown by water proves to be a troublesome interfering factor in the study of aqueous solutions by the IR method. 

It is clear that many solvents interact and produce new H bonding equilibria involving the solvent. These additional equilibria furnish an extraneous and interfering factor in a reference spectrum. On the other hand, a dilute solution of a proton donor in a basic solvent involves well defined species and avoids the usual complication of polymeric equilibria. Consequently, the spectral examination of such systems... 

U4. Umetani, N., Polarographic studies on gastric juice protein. Part I. Studies on interfering factor in formation of polarogram of gastric juice. 7. Japan. Soc. Internal. Med. 47, 141-151 (1958). 

The determination of ammonia in blood is carried out enzymatically, which is considered to be specific, precise and simple. (48) Serious mistakes can easily occur during the preanalytical phase of ammonia determination, making it imperative to comply with the standardized method of taking a blood sample, (s. p. 91) EDTA blood should be taken with the addition of sodium borate and L-serine. Furthermore, elevated serum y-GT activity and increased thrombocytes cause the ammonia level to rise, as does cigarette smoking prior to blood collection. Even minor haemolysis (e. g. in the event of prolonged transport) will spoil the blood for ammonia determination, since the ammonia concentration of erythrocytes is three times that found in plasma. Besides these interfering factors, ammonia concentration is influenced by (7.) the metabolic performance of the urea cycle, (2.) the extrahepatic formation and elimination of ammonia, and (5.) the acid-base status. 

The samples of products are incubated with Limulus amoebocyte lysate at 37°C. If endotoxins are present a solid gel forms, indicating the presence of endotoxins. The British Pharmacopoeia (2002) describes six separate methodologies for the test for endotoxin. These are (A) gel-clot limit test (B) gel-clot semi quantitative (C) turbidimetric kinetic method (D) chromogenic kinetic method (E) chro-mogenic end-point method and (F) turbidimetric end-point method. There are checks for interfering factors. Any validated method may be used, but the gel-clot method is the referee test in the case of dispute. Coloured products cannot be tested by... 

Two different types of immunoassays, a competitive-type and an inhibition-type, were developed and compared for the insecticide, endosulfan. The detection range of both assay types was similar, 3-500 ng/ml for the competitive-type and 5-500 ng/ml for the inhibition-type assay. Metabolites of endosulfan and other insecticidal chloro-hydrocarbons possessing a hexachlorocyclopentene structure exhibited considerable crossreaction in both assays, so these immunoassays could be used for detection of class-specific compounds. The inhibition-type immunoassay showed less susceptibility to interfering factors and, therefore, seemed to be more suitable for environmental analysis. 

It is more diflBcult to secure conclusive evidence of the specificity of a chemical method, when applied to a biological system (B7). Since the constituent will almost certainly have to be determined as one component in a mixture, the possible interfering effects of some (ideally all) of these other substances need to be determined, each over the range of concentrations liable to be met with in practice. Whereas the accuracy of a method can best be determined by recovery experiments, which depend on the availability of a pure sample of the compound under investigation, the specificity of a technique and the effects of possible interfering factors can be more readily investigated by experiments involving radioactive isotopes these isotopic assessments of specificity have so far not been widely applied in clinical chemistry. 

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