Semi-quantitative tests

Semi-quantitative tests These methods are based on 

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In general, limit tests are quantitative or semi-quantitative tests particularly put forward to identify and control invariably small quantities of impurity that are supposed to be present in a pharmaceutical substance. Obviously the amount of any single impurity present in an official substance is usually small, and therefore, the normal visible-reaction-response to any test for that impurity is also quite small. Hence, it is necessary and important to design the individual test in such a manner so as to avoid possible errors in the hands of various analysts. It may be achieved by taking into consideration the following three cardinal factors, namely ... 

A limit test is a semi-quantitative test that allows the determination of the presence of a specific compound above a well-defined concentration level. The determinations are done according to an external calibration calculation procedure, either with or without internal standardization. The calibration is perfotmed against a reference solution at threshold level (e.g., 0.10% w/w compared to the nominal concentration of the sample solution at 100% w/w). 

Due to the different nature of insulin antibodies that can be formed a defined analyte does not exist and a calibration is not possible. The tracer binding test is a semi-quantitative test without a standard curve. Three titer controls (T1-T3) containing low, medium and high levels of free anti-insulin antibodies and a blank control (TO) to determine the non-specific tracer binding (NSB) are measured in each run. Total activity of 200 p.1 tracer is also measured in each run. 

Limit tests are quantitative or semi-quantitative tests used in the British Pharmacopoeia to identify and control small quantities of impurity that... 

Semi-quantitative tests Most probable number (MPN) tests These are based on the presence/absence test. Decimal dilutions of the test sample are inoculated into a set number of tubes of liquid media. Bacterial densities can be determined from... 

Most biochemical analyses arc quantitative, although simple qualitative or semi-quantitative tests such as those for the presence of glucose in urine are commonly encountered in methods used for biochemistry testing away from the laboratory. Many tests measure the amount of the analyte in a small volume of the sample, whether that is blotKl, plasma, serum, urine or some other fluid or ti.ssue. The test results are commonly expressed in molar units. A mole of any compound always contains 6 x 10 molecules. Describing how much of an analyte is present in moles indicates how many molecules of the substance are present. Molar units can be converted to mass units one mole is the molecular weight of the substance in grams. 

A semi-quantitative test for measuring H2S in water utilises Alka-Seltzer, and should be relatively unaffected by color or chemical interference. Keep in mind that H2S is easily oxidised. Therefore, unless the sulphide is precipitated, any measurement in water should proceed rapidly after sample collection with minimal aeration. 

TING, B-Y, WINER, W.O. RAMALINGHAM, S. -An Experimental Investigation of the Film to Substrate Bond Strength of Sputtered Thin Film Using a Semi-Quantitative Test Method. Trans ASME, Vol 107, Page 478, October 1985. 

Semi-quantitative Tests for Ammonia, Iron, Chloride, Phosphate... 

A semi-quantitative test for the estimation of urinary calcium excretion. It consists of adding oxalic acid and ammonium oxalate in acetic acid to the urine and assessing the degree of turbidity of the calcium oxalate precipitate. 

Turbidimetry can be used for the measurement of plasma proteins by their reaction with antisera to form light scattering immune precipitates. Many qualitative and semi quantitative tests are also used in clinical chemistry, e.g. the flocculation tests. 

Rapid semi-quantitative tests for inhibitors in styrene monomer... 

Organ functions are normally characterized by blood concentrations of metabolites or enzyme activities. In vivo stable isotope tests are considered as dynamic and (semi) quantitative tests. Dynamic reflection of organ functions can therefore be obtained by application of stable isotopes. A stable isotope-labeled precursor for a specific function is administered and the rate or degree of metabolism is... 

Quantitative determination of the various organic and inorganic components detected by the qualitative tests. Most often, ion chromatography is used for determination of sulfate phosphate and polyphosphates chelates such as NTA, EDTA, and gluconate and other lower molecular weight components. Capillary electrophoresis may also be used. Gas chromatography is applied to quantification of solvents and propellants. Specialized tests are required to determine poly aery late builders One quick semi-quantitative test is based on pyrolysis GC-MS of a water extract after addition of tetramethylammonium hydroxide. Peaks of methyl acrylate and methyl fumarate indicate the presence of acrylate and maleate polymers and/or copolymers (14). 

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