Analytical reagents definition

Amide oximes can be represented by the general formula RC(=NOH)NH2 and the ligand of this class which has received maximum attention is benzamide oxime (R = Ph). A good test of amide oxime function is the formation of a red-brown colour with iron(III) in neutral solution. The use of amide oximes as analytical reagents for the estimation of various metal ions has been reviewed. However, as stated in a later review, not much definitive structmal information is available on these complexes. For example, although on the basis of IR data, benzamide oxime complexes of copper(II) and nickel(II) have been assigned the structure (28), yet even magnetic and spectral data are not available. 

The test identifies the substance to be examined as an alkaloid. Alkaloids are a very large class of substances with a somewhat vague definition. Traditionally alkaloids have been identified with the use of four analytical reagents ... 

In electroanalysis, coulometry is an important method in which the analyte is specifically and completely converted via a direct or indirect electrolysis, and the amount of electricity (in coulombs) consumed thereby is measured. According to this definition there are two alternatives (1) the analyte participates in the electrode reaction (primary or direct electrolysis), or (2) the analyte reacts with the reagent, generated (secondary or indirect electrolysis) either internally or externally. 

Some other sources have definitions that are different from the one given above [7,14]. The US Pharmacopeia [7] defines ruggedness as The ruggedness of an analytical method is the degree of reproducibility of test results obtained by the analysis of the same sample under a variety of normal test conditions, such as different laboratories, different analysts, different instruments, different lots of reagents, different elapsed assay times, different assay temperatures, different days, etc. Ruggedness is normally expressed as the lack of influence on test results of operational and environmental variables of the analytical method. Ruggedness is a measure of reproducibility of test results under normal, expected operational conditions from laboratory to laboratory and from analyst to analyst . In fact this is nearly the definition of reproducibility. This definition is also followed by other authors [15]. 

Consistent with these definitions, there are two methods for IDL determination. The first method consists of multiple analyses of a reagent blank, followed by the determination of the standard deviation of the responses at the wavelength of the target analyte. The standard deviation multiplied by a factor of three is the IDL. This calculation defines the IDL as an analyte signal that is statistically greater than the noise. 

Equivalent weight A specialized basis for expressing mass in chemical terms similar to, but different from, molar ma.s.s. As a consequence of definition, one equivalent of an analyte reacts with one equivalent of a reagent, even if the stoichiometry of the reaction is not one to one. 

Moreover, the presence of an artefact in the analytical path for analyte separation/concentration is not included in the definition of X. Also, the sample, reagent and carrier solutions are considered as a whole, so that differences in the diffusion coefficients of the different chemical species are not considered. The occurrence of chemical reactions altering the sample dispersion [113] is not considered. 

---