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Matrix components definition

Matrix Components The term matrix component refers to the constituents in the material aside from those being determined, which are denoted as analyte. Clearly, what is a matrix component to one analyst may be an analyte to another. Thus, in one hand for the case of analyses for elemental content, components such as dietary fibre, ash, protein, fat, and carbohydrate are classified as matrix components and are used to define the nature of the material. On the other hand, reference values are required to monitor the quality of determinations of these nutritionally significant matrix components. Hence, there is a challenging immediate need for certified values for dietary fibre, ash, protein, fat, and carbohydrate. Concomitantly, these values must be accompanied by scientifically sound definitions (e.g. total soluble dietary fibre, total sulpha-ted ash, total unsaturated fat, polyunsaturated fat, individual lipids, simple sugars, and complex carbohydrates). [Pg.287]

It is important to note that the matrix effects, interferences, and variability in method efficiency are to be factored in when determining the MDL. If this was not done then only the background noise (see Figure 2, peak 13) would be considered in the definition of the MDL. In real-life samples there is a good possibility that matrix component peaks would either co-elute or elute at retention times close to... [Pg.67]

To obtain a high selectivity, i.e., discrimination between the analytes and various unwanted matrix compounds, membrane extraction has a clear advantage over other sample preparation techniques, as all compounds that reach the analytical instalment must travel through the membrane. There is no direct connection and possibility for transferring compounds into the analytical instmment in other ways. This is not the case with other extraction techniques. With SPE, SPME, etc., there is a definite possibUity that matrix components are absorbed on the sorbing phase and subsequently being eluted into the extract. With LEE, such a transfer is less probable and it is generally considered that extracts after LLE are cleaner. The possible and common problem of the formation of emulsions at the phase interface with LLE, which is avoided with aU types of membrane extraction, is a source of contamination across the phase border. [Pg.356]

In Conference Report II, selectivity was defined as follows Selectivity is the ability of the bioanalytical method to measure unequivocally and to differentiate the analyte(s) in the presence of components, which may be expected to be present . Typically, these might include metabolites, impurities, degradants, matrix components, etc. [10]. This definition is very similar to the one established by the ICH [13], but takes into account the possible presence of metabolites, and thus is more applicable for bioanalytical methods. [Pg.2]

Ml - Aermodynamic factor for diffusivity (Eq. 1.2.26), m mol/J s Xi - the mole fraction of component i Q.ij - phenomenological coefficients of ij component pairs [S2] - phenomenological coefficient matrix, positive definite... [Pg.37]

The matrix gp, represents the components of a covariant second-order tensor called the metric tensor , because it defines distance measurement with respect to coordinates To illustrate the application of this definition in the... [Pg.264]

Validation should be carried out for each component of the residue definition in each sample matrix used for risk assessment purposes. [Pg.34]

Principles and Characteristics A first step in additive analysis is the identification of the matrix. In this respect the objective for most polymer analyses for R D purposes is merely the definition of the most appropriate extraction conditions (solvent choice), whereas in rubber or coatings analysis usually the simultaneous characterisation of the polymeric components and the additives is at stake. In fact, one of the most basic tests to carry out on a rubber sample is to determine the base polymer. Figure 2.1 shows the broad variety of additive containing polymeric matrices. [Pg.30]

In the ideal case only the diagonal elements of the sensitivity matrix are different from zero. Then no component disturbs any other and the analytical procedure works selectively (see Sect. 7.3). The K-malrix is defined analogously except that the elements are called kij, their definition is the same as the Sij according to Eq. (7.16). [Pg.213]

The above-mentioned statistical characteristics of the chemical structure of heteropolymers are easy to calculate, provided they are Markovian. Performing these calculations, one may neglect finiteness of macromolecules equating to zero elements va0 of transition matrix Q. Under such an approach vector X of a copolymer composition whose components are X = P(M,) and X2 = P(M2) coincides with stationary vector n of matrix Q. The latter is, by definition, the left eigenvector of this matrix corresponding to its largest eigenvalue A,i, which equals unity. Components of the stationary vector... [Pg.147]

By definition of a and /3, 54 the sum of the Nm components of 7 is unity. Thus, by extending the definition of linear mixture to include the condition that (3 must be nonnegative,55 the last Nmf = Nm - I components of 7 can be used to define the mixture-fraction vector.56 The transformation matrix that links to ccv can be found by rewriting (5.84) using the fact that the components of 7 sum to unity ... [Pg.182]

Both S, by definition, and F through equation (4.4.12), are centered, i.e., their expectation is a null matrix. Therefore the sample covariance matrix between the reduced data and the components is... [Pg.241]

The coupling of these improvements needs to be proven to meet endurance goals operation at pressure will definitely require design changes. The studies described in the recent literature provide updated information on promising development of the electrodes, the electrolyte matrix, and the capability of the cell to tolerate trace constituents in the fuel supply. The objectives of these works are to increase the life of the cells, improve cell performance, and lower cell component costs. Descriptions of some of this work follow. [Pg.138]

The definitions of the first and second order magnetic perturbation operators are given helow. In the nonrelativistic formalism these operators are two-component operators, in the Kutzelnigg formalism all operators are to he multiplied hy the four-component matrix. All operators are given in the atomic unit system and we do not apply QED corrections so that the free electron g-factor is precisely equal to 2. [Pg.380]

There is a definite need for further work on the compatibility of additives from the perspective of their interfering with biological or chemical processes that are needed to disrupt the plastic matrix. Although additives are valuable components when they improve the properties of a plastic, their use cannot be sanctioned if they prevent degradation of the plastic. [Pg.93]

From their definition, it follows that each of the spin components of the 2-G matrix are positive semidefinite. The semidefinite positiveness of these matrices constitutes a much more exacting set of conditions than the well-known single A-representability G-condition, since the former conditions imply the latter one but not conversely. [Pg.211]

The preceding definition of a kinetic SDE reduces to that given by Hiitter and Ottinger [34] in the case of an invertible mobility matrix X P, for which Eq. (2.268) reduces to the requirement that Zap = K. In the case of a singular mobility, the present definition requires that the projection of Z p onto the nonnull subspace of K (corresponding to the soft subspace of a constrained system) equal the inverse of within this subspace, while leaving the components of Z p outside this subspace unspecified. [Pg.142]


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See also in sourсe #XX -- [ Pg.162 ]




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