Method specificity

British Standards National standards involving lest methods, specifications for quality, safety, performance, etc., and codes of practice. Standards are prepared by the British Standards Institution. Ref. British Standards Year Book. 

The most extensive body of tests are provided under the auspices of ASTM Standard methods. Specific ASTM test designations and descriptions are available (48). The other compendium of fire-retardant tests are contained ia Federal Test Method Standards 191A (49). 

Both nicotinic acid and nicotinamide have been assayed by chemical and biological methods. Owing to the fact that niacin is found in many different forms in nature, it is important to indicate the specific analyte in question. For example, if biological assay procedures are used, it is necessary to indicate whether the analysis is to determine the quantity of nicotinic acid or if niacin activity is the desired result of the analysis. If nicotinic acid is desired, then a method specific for nicotinic acid should be used. If quantitation of niacin activity is the desired outcome, then all compounds (bound and unbound) which behave like niacin will assay biologically for this substance (1). 

Analytical and Test Methods, Specification, and Safety Factors... 

Table 5. ASTM Graphite-Related Test Methods, Specifications, Recommended Practices, and Definitions ...

A six-port valve was first used to interface the SEC microcolumn to the CZE capillary in a valve-loop design. UV-VIS detection was employed in this experiment. The overall run time was 2 h, with the CZE runs requiring 9 min. As in the reverse phase HPLC-CZE technique, runs were overlapped in the second dimension to reduce the apparent run time. The main disadvantage of this yu-SEC-CZE method was the valve that was used for interfacing. The six-port valve contributed a substantial extracolumn volume, and required a fixed volume of 900 nL of effluent from the chromatographic column for each CZE run. The large fixed volume imposed restrictions on the operating conditions of both of the separation methods. Specifically, to fill the 900 nL volume, the SEC flow rate had to be far above the optimum level and therefore the SEC efficiency was decreased (22). 

Four types of techniques for separating the bound fraction P Q from the reagent mixture are in common usage, loosely termed double antibody, solid phase, charcoal adsorption and solution precipitation. The first type is used with radioimmunoassay methods specifically, while the other three types can be used with both radioassay and radioimmunoassay methods. 

Here we develop the method specifically from the point of view of contingency tables and within the context of weighted metrics. We will show that LLM differs only from CFA in the type of preprocessing that is applied to the contingency table. The results of both approaches are often similar when there are no extreme contrasts in the data. 

The results of activation analysis are subject to well known and common analytical sources of uncertainty, as well as method specific uncertainties, e.g. summarized by Greenberg (1997), and also in Section 2.2. In order for INAA experiments to measure differences in induced activity, i.e. differences due to heterogeneity in the amount of analyte in a given test portion, the experimental procedure is designed to allow only the following uncertainties to be part of the result ... 

Pharmacopoeial standards and substances are established and distributed by pharmacopoeial authorities following the general principles of this Guide. It should be noted, however, that a different approach is used by the pharmacopoeial authorities to give the user the information provided by certificates of analysis and expiration dates. Also, the uncertainty of their assigned values is not stated since it is negligible in relation to the defined limits of the method-specific assays of the pharmacopoeias for which they are used. ... 

In such a case, based on the results of a collaborative study, a content is assigned to the corresponding reference substance which is method specific, i.e. it is only to be used with the method described in the monograph. The establishment of these substances is described in more detail later in the Chapter. 

The laboratory of the European Pharmacopoeia applies the method specific approach (inter-laboratory study) as has been previously described (Technical Guide for the Elaboration of Monographs 1996). 

Pendlington aw, Meuree-Vanlaethem N, Brookes A (i<)g6) The Method Specific Certification of the Mass Fraction of Dietary Fibre in Lyophilised Haricot Beans, Carrot, Apple, Full Fat Soya Flour and Bran Breakfast Cereal Reference Materials CRMs 514, 515, 516, 317 and 518. European Commission Report EUR 17451 EN, Luxembourg. 

A range of biomarkers (biological markers) have been developed for the detection of microorganisms using both their genetic (DNA and RNA) and biochemical components. Most methods have originated from studies on pure isolates and have been adapted to identify and quantify either the total or a sub.set of the microbial biomass in a sample. In these methods,. specific taxonomic or pheno-... 

Owing to the complexity of multi-residue methods for products of animal origin, it is not possible to outline a simple scheme however, readers should refer to methods described in two references for detailed guidance (Analytical Methods for Pesticides in Foodstuffs, Dutch method collection and European Norm EN 1528. ) There is no multi-method specifically designed for body fluids and tissues. The latter matrix can be partly covered by methods for products of animal origin. However, an approach published by Frenzel et al may be helpful (method principle whole blood is hemolyzed and then deproteinized. After extraction of the supernatant, the a.i. is determined by GC/MS. The LOQ is in the range 30-200 ag depending on the a.i.). 

The following reagents have been tested for use in this method. Specific brands are listed to aid in finding suppliers. 

The first recommended soil method for oxime carbamates is the method of Honing et al. by HPLC/MS. The LOQ of the method, specifically for aldicarb, methomyl, and oxamyl, is 0.05mgkg. Soil (lOg) is Soxhlet extracted for 16h with acetone-dichloromethane (1 1) using double-thickness cellulose extraction thimbles (80 X 22-mm i.d.). Prior to extraction, the Soxhlet system and the thimbles are cleaned for 14 h by refluxing with methanol. The extracts are removed and concentrated nearly to dryness in a rotary evaporator operating at 35 °C evaporation to dryness... 

Scheme 4.5 illustrates HPLCphase selection. Column manufacturers may have an applications database from which they can recommend a column and a method. Specific methods have been established for quite a large number of analytes, such as additives (e.g. antioxidants). Column selection and column technology have been reviewed [549]. Contrary to GC, and with the exception of SEC, selectivity in HPLC is determined not by the column alone but also by the mobile phase. There is therefore no one-for-one assignment between an analytical problem and the best column for this problem. 

This chapter reviewed some of our group s contributions to the development and application of QM/MM methods specifically as applied to enzymatic reactions, including the use of sequential MD/QM methods, the use of effective fragment potentials for reaction mechanisms, the development of the new QM/MM interface in Amber, as well as the implementation and optimization of the SCC-DFTB method in the Amber program. This last implementation allows the application of advanced MD and sampling techniques available in Amber to QM/MM problems, as exemplified by the potential and free energy surface surfaces for the reaction catalyzed by the Tripanosoma cruzi enzyme /ram-sialidasc shown here. 

There are several other methods which have been used in the experimental determination of electron impact ionization cross sections. Nottingham and Bell76,77 developed a method specifically for the purpose of accurately determining the absolute electron impact ionization cross section of mercury. A semicircular electron velocity analyzer included in their design ensured that very high energy resolution was possible since only electrons of the required velocity emerged from the analyzer into the ionization chamber. Other aspects of the experiment are similar to the condenser plate method. 

Equation (9.53) for the desired molecular field is nonlinear, typically solved iteratively. For this molecular-field approach to become practical, an alternative to this nonlinear iterative calculation is required. A natural idea is that a useful approximation to this molecular field might be extracted from simulations with available generic force fields. Then with a satisfactory molecular field in hand, the more ambitious quasichemical evaluation of the free energy can be addressed, presumably treating the actual binding interactions with chemical methods specifically. This is work currently in progress. 

In related work a library of 1,458 peptide ligands and various metal salts was tested in hydrolysis reactions of (p-nitrophenyl)phosphates.35 An active substructure composed of polymer-bound histidine in combination with Eu3+ was identified by further dissecting the original hit structure. It needs to be pointed out that catalytically active polymer beads can also be tested for catalytic activity using IR-thermography. In a seminal paper this was demonstrated using 7,000 encoded polymer beads prepared by split-and-pool methods, specifically in the metal-free acylation of alcohols.36... 

Publication NMAB 318-2. Fire Safety Aspects of Polymeric Materials, Vol. 2 - Test Methods, Specifications and Standards National Academy of Sciences Washington, D. C., Technomic Publishing Co., 1979. 

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