Specifity, analytical method

In a general way, the identification of asbestos fibers can be performed through morphological examination, together with specific analytical methods to obtain the mineral composition and/or stmcture. Morphological characterization in itself usually does not constitute a reHable identification criteria (1). Hence, microscopic examination methods and other analytical approaches are usually combined. 

These conceptual goals are attained by several combinatorial methods and tools. Characteristic for combinatorial chemistry is the synthesis on solid support or by polymer-supported synthesis, allowing for much higher efficiency in library production. Synthesis can be conducted either in automated parallel synthesis or by split-and-recombine synthesis. Centerpieces of combinatorial methods further include specific analytical methods for combinatorial... 

N-Nitroso contamination in pesticide products was first reported by D. Fine and co-workers (] ) who had developed a novel and specific analytical method for N-nitroso compounds, called thermal energy analysis. 

Methoxychlor [1,1,l-trichloro-2,2-bis(p-methoxyphenyl)-ethane], benzene hexachloride (BHC), chlordan, and toxaphene are chlorinated compounds of recognized importance in the insecticide field. Other chlorinated compounds now undergoing-field testing experiments will, no doubt, soon be added to the list. The need for specific analytical methods is familiar to those concerned with the analysis of formulations containing one or more of the above insecticides. 

Colorimetric methods (3, 6-10), some of which are specific, have been developed for the determination of DDT in small amounts. For benzene hexachloride (hexachloro-cyclohexane), chlordan, and toxaphene, however, specific analytical methods have not been developed, and their residues have been evaluated by the determination of organically bound chlorine. The procedure comprises extraction of the insecticide residue from the sample with benzene or other suitable organic solvent, evaporation of the solvent, treatment of the residue with isopropyl alcohol and metallic sodium, and finally determination by standard methods of the amount of chloride ion formed. 

Commercial mixtures of surfactants comprise several tens to hundreds of homologues, oligomers and isomers of anionic, nonionic, cationic and amphoteric compounds. Therefore, their identification and quantification in the environment is complicated and cumbersome. The requirement of more specific analytical methods has prompted a replacement of many of the separate steps in traditional methods of analysis, usually non-chromatographic, by chromatographic tools. 

Recent studies using various laboratory techniques and specific analytical methods such as liquid chromatography (LC) or gas chromatography (GC) have reported considerable degrees of disappearance of the parent test substance in particular when LAS [45-48] or NPEOi and NPEO2 [13,16] were used. Primary biodegradation between... 

Specificity NMR spectroscopy is a specific analytical method by its nature. Each type of proton located in a different chemical or magnetic environment in the same or different molecule can be differentiated through its characteristic resonance frequency (Figure 12.1A). Thus, every proton-containing chemical has a unique set of proton NMR signals that can be readily identified. Although the NMR signals may be dependent on the solvent conditions (for example, temperature, pH, hydrophobicity, etc.), each molecule still can be uniquely identified in an NMR spectrum. 

Regulatory authorities recognize that, in spite of all the control systems put in place, deviations and changes are sometimes inevitable. A robust GMP system includes procedures to handle, review, and approve changes in raw materials, specifications, analytical methods, facilities, equipment, processes, computer software, and labeling and packaging. All the changes have to be documented with references for traceability. 

Many methods have been used to quantify steroidal compounds. These include RIA, gas chromatogra-phy-mass spectrometry (GC/MS), high-performance liquid chromatography (HPLC), and liquid chroma-tography-mass spectrometry (LC/MS). Although these techniques are successful in the analysis of steroids, it has been difficult to achieve quantitative analysis of small samples of neurosteroids because of their low concentrations in nervous tissues. Highly specific analytical methods are required to analyze small quantities of neurosteroids and their sulfates. Only with extremely sensitive methods of analysis is it possible to discover whether neurosteroids are synthesized in nervous tissues in quantities sufficient to affect neuronal activity, and whether these neurosteroids are distributed uniformly in brain. 

The goal of harmonization is to bring the policies, standards, monograph specifications, analytical methods, and acceptance criteria of pharmacopoeias into agreement. Such imity may, however, not always be achievable. Where imity cannot be achieved, harmonization means agreement based upon objective comparability and a clear statement of any differences. The goal, therefore, is harmony, not imison. 

Increases in processor speeds and storage capacity allowed these system to acquire and process data rapidly. Many fourth-generation systems became nodes in laboratory computer UMS networks. They communicate with host computers to receive instructions for analyses and for transferring results. Programs and values of parameters for specific analytical methods can be stored in memory and recalled by the analyst as needed. While the analyst found interaction with these systems easier, he or she became further removed from the system components and often more dependent on the vendor s software. Tailoring requirements to individual user requirements was often not viable with this approach. 

Traceability and MU both form parts of the purpose of an analytical method. Validation plays an important role here, in the sense that it confirms the fitness-for-purpose of a particular analytical method [4]. The ISO definition of validation is confirmation by examination and provision of objective evidence that the particular requirements of a specified intended use are fulfilled [7]. Validation is the tool used to demonstrate that a specific analytical method actually measures what it is intended to measure and thus is suitable for its intended purpose [2,11]. In Section 8.2.3, the classical method validation approach is described based on the evaluation of a number of method performance parameters. Summarized, the cri-teria-based validation process consists of precision and bias studies, a check for... 

Corticosteroids potentially used in food-producing animals include a variety of compounds such as cortisone, cortisol, prednisone, prednisolone, methylpredniso-lone, betamethasone, dexamethasone, flumethasone, fluoroprednisolone, isoflu-predone, and triamcinolone. Corticosteroid administration to feedlots as growth-promoting agents has been recently introduced illicitly in animal production because of their ability to promote water retention in the body. This use has been strongly enhanced for commercial reasons, in order to produce meat more appealing to consumers, due to the juicy and lean look. It is therefore crucial to rely on accurate, sensitive and specific analytical methods to measure residues in biological samples. 

Today, highly sensitive and specific analytical methods are used and together with the new methods of molecular biology have a major impact on the development of the science. 

Jhe distribution of hydrogen types in coals continues to be a subject of considerable interest in coal structure studies. Published data indicate that the fraction of aromatic hydrogens usually increases with increasing rank, but the absolute values depend on the specific analytical method used (7). Hydrogen type analysis of a single coal based on the application of NMR spectroscopy to the soluble fraction from depolymerization with phenol-BFa has been reported by us (3). The conversion of coal to soluble fragments in substantial yields under very mild conditions permits a reliable determination of the hydrogen types by NMR analysis, and these results can be extrapolated to the parent coal with considerable confidence. 

AS Treatability and Environmental Concentrations. Studies of AS degradation in the environment or during actual sewage treatment have been limited because specific analytical methods to measure AS were not available until recently. We developed a method that isolated AS from water samples on a strong anion-exchange column. The AS were then hydrolyzed to a fatty acid and analyzed by gas chromatography with flame-ionization detection (GC-FID). The method has a detection limit of 5 xg/L per component (50). 

Note Examples of specific analytical methods are given in the ISBT document. Analytical Methods for C02 Analysis. 

Analytical methodology—This section should refer to the specific analytical method(s) to be used for the specific products, cleaning agents, and equipment for the protocol being evaluated. Many companies choose to have the detailed analytical methodology described in a separate report and reference only the report number in the actual protocol. There are certain parameters that should be included in the actual protocol, however. For example, the sensitivity of the analytical method, expressed either as the LOD or LOQ, should be included in the protocol since it will be necessary that the sensitivity of the analytical method be below the acceptance criteria for the residues so that a result of none detected can be interpreted, ft must be remembered that none detected does not mean that there was no residue present, but only that the level of residue was below the limit of detection of the analytical method. 

A second analytical parameter that is extremely critical for cleaning evaluation is the recovery factor for the specific analytical method. This is usually determined by spiking known amounts of the expected residue on surfaces of the same material (e.g., stainless steel, glass, plastics) as the equipment to be sampled. The recovery is defined as... 

Interest in PCNs was renewed in the 1990s as congener-specific analytical methods became more routine and precise. PCNs are now known to be as widespread in the environment as most other halogenated compounds, as indicated by their occurrence in the ambient air [19-21] and biota [22-24] of... 

Because natural samples often have background levels of organic material and the chemical substrate concentration is low, indirect measurement techniques can not be used and 14C, other radiolabelled techniques, or sensitive specific analytical methods are required. If radiolabelled methods are used, the cost of the method increases, due to the cost of synthesis of the radiolabelled material. Use of radiolabelled chemicals is required for registration studies on environmental fate testing of pesticides. 

The CEA launched in 2001 an integrated programme to compare the most promising way to produce hydrogen using the high temperature heat available from a VHTR. In order to develop its own expertise on thermochemical cycle assessment, CEA has chosen to develop a scientific approach based on data acquisition (development of devoted devices and specific analytical methods) and modelling (physical models, flow sheet analysis, systemic approach). 

Equipment and area should be verified as clean using wipe sampling techniques (when compound specific analytical methods are available)... 

Specific analytical methods have not been developed for dialkyl alkylphosphonates. They are usually sufficiently hydrophilic to be partially extracted by water from matrices such as soil and they are detected by the screening methods described above under positive ESI and APCI conditions. They are easily differentiated from isomeric alkyl alkylphosphonic acids by their lack of response under negative ionization conditions (Section 6.2.3, Figure 8) (14). 

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