Selective analytical method

Table 7.7. Spatial resolving power Rsmfice of selected analytical methods. For reasons of comparability an area of 1 mm2 has been taken in the case of 3-D SIMS a volume of v = 0.1 mm3 is taken as the basis... 

See Selectivity, above, and Table 21.9. Industrial problems usually generate samples with complex matrices and many potential interferences. Selective analytical methods or sample preparation are normally required. Separation techniques are quite commonly used. In the average industrial analytical lab, the most numerous instruments are usually gas or liquid chromatographs because they combine separation with detection. 

Table 5.2 Summary of selected analytical methods for molecular environmental geochemistry. AAS Atomic absorption spectroscopy AFM Atomic force microscopy (also known as SFM) CT Computerized tomography EDS Energy dispersive spectrometry. EELS Electron energy loss spectroscopy EM Electron microscopy EPR Electron paramagnetic resonance (also known as ESR) ESR Electron spin resonance (also known as EPR) EXAFS Extended X-ray absorption fine structure FUR Fourier transform infrared FIR-TEM Fligh-resolution transmission electron microscopy ICP-AES Inductively-coupled plasma atomic emission spectrometry ICP-MS Inductively-coupled plasma mass spectrometry. Reproduced by permission of American Geophysical Union. O Day PA (1999) Molecular environmental geochemistry. Rev Geophysics 37 249-274. Copyright 1999 American Geophysical Union...

Gallay, W., Environmental Pollutants — Selected Analytical Methods, Butter-worths, London (1975). 

The selectivity of a method is a measure of how capable it is of measuring the analyte alone in the presence of other compounds contained in the sample. The most selective analytical methods involve a chromatographic separation. Detection methods can be ranked according to their selectivity. A simple comparison is... 

Process research route and sequence selection, analytical method development ON I VO 3 ... 

Select Analytical Methods In order to ensure reproducibility process control is required. Especially the liquid ozone concentration must be measured (see Section B 2.5). 

Select Analytical Method In order to calculate the mass balances necessary for data evaluation, the concentration of the incoming and outgoing ozone gas stream as well as the liquid concentration of ozone and/or hydrogen peroxide must be measured. In case of U V-radiation the amount of photons should be measured by actinometry. 

In summary, we can say that isotope dilution analysis is a highly sensitive, selective analytical method capable of high precision. It offers the opportunity to determine the amount of material present in a system without the need for a quantitative separation of the material from the system. The applications of isotope dilution analysis cited in the literature are myriad. Perhaps the best summary of these applications is the book by Tolgyessy, Braun, and Krys (1972). 

Crown ethers and cryptands, either alone or fixed on a polymer support [2.89], have been used in many processes, including selective extraction of metal ions, solubilization, isotope separation [2.90], decorporation of radioactive or toxic metals [2.17, 2.49], and cation-selective analytical methods [2.89, 2.91, 2.92] (see also Sect. 8.2.2 and 8.4.5). A number of patents have been granted for such applications. 

The assessment of degradation in pharmaceutical products involves two aspects of analytical measurement. First, a selective analytical method must be available for accurate assay of the parent drug compound, in order to correctly measure any loss. Second, methodology should be in place for quantification of the degradation products formed. Ideally, when degradation occurs, the measured amount of parent drug lost should correlate well with the measured increase in degradation products. This correlation is referred to as mass balance )- More recently, the International Conference on Harmonization (ICH) has provided a definition of mass balance material balance as follows ... 

Papilloud, S. and W. Haerdi (1995). Supercritical fluid extraction of triazine herbicides A powerful selective analytical method. 

Select analytical methods appropriate for the intended use of the data by comparing the action levels to the method detection limits. 

Pertraction through SLM is widely used in analytical chemistry for separation and preconcentration of solutes before application of selected analytical method and it is discussed in refs. [32-34, 184, 185]. 

Supplement to the 15 th edn. of Standard Methods for the Examination of Water and Waste Water. Selected Analytical Methods Approved and Cited by the US Environmental Protection agency. American Public Health Association, American Waterworks Association, Water Pollution Control Federation, Sept. (1978). Methods S60 and S63. Methods for benzidine, chlorinated organic compounds, pentachlorophenol and pesticides in water and waste water (Interim, Pending issuance of methods for organic analysis of water and wastes, Sept. 1978), Environmental Protection Agency, Environmental Monitoring and Support Laboratory (EMSL). 

Method S73. Supplement to the 15th ed. of Standard Methods for the Examination of Water and Waste Water. Selected Analytical Methods Approved and Cited by US Environmental... 

Selecting analytical methods to investigate the presence or absence of either a finite or open ended list of chemicals. 

Selected analytical methods, adopted by the American Oil Chemists Society (AOCS)22 for characterizing the composition, structure, physical properties, and stability of fats and oils, are summarized below. Prescribed equipment must be used and... 

Scientific Committee on Problems of the Environment (SCOPE), Working Group on Methodology of Determination of Toxic Substances in the Environment, Environmental Pollutants Selected Analytical Methods (SCOPE 6), Ann Arbor Science Publishers, Ann Arbor, MI, 1975. 

Currently there is a trend toward the synthesis and large-scale production of a single active enantiomer in the pharmaceutical industry [61-63]. In addition, in some cases a racemic drug formulation may contain an enantiomer that will be more potent (pharmacologically active) than the other enantiomer(s). For example, carvedilol, a drug that interacts with adrenoceptors, has one chiral center yielding two enantiomers. The (-)-enantiomer is a potent beta-receptor blocker while the (-i-)-enantiomer is about 100-fold weaker at the beta-receptor. Ketamine is an intravenous anesthetic where the (+)-enantiomer is more potent and less toxic than the (-)-enantiomer. Furthermore, the possibility of in vivo chiral inversion—that is, prochiral chiral, chiral nonchiral, chiral diastereoisomer, and chiral chiral transformations—could create critical issues in the interpretation of the metabolism and pharmacokinetics of the drug. Therefore, selective analytical methods for separations of enantionmers and diastereomers, where applicable, are inherently important. 

The first example presents a typical process from our research environment, where a chemical synthesis is transferred from development to production. In this situation validation of the chemical process is performed throughout, including variations of process parameters for intermediates that are not isolated. For these intermediates a pre-selected analytical method is normally... 

Dimethylhydrazine, which has no free-Xt 1 group, cannot be derivatized in this way but may be quantified by chromatographic methods that do not require derivatization (Fiala and Kulakis 1981). Details of selected analytical methods for hydrazine and dimethylhydrazines in biological samples are summarized in Table 6-1. 

Development of selective analytical method for the determination of artemisinin poses challenging problems because it lacks ultraviolet (UV) absorption or fluorescent chromophores and does not possess functional groups with potential for derivatization. This study reports the determination of artemisinin by liquid chromatography with on-line post-column UV irradiation and peroxyoxalate chemiluminescence (PO-CL) detection. A similar method as previously reported by us for the determination of organic peroxide. In this method, after artemisinin is eluted from the HPLC column, it is UV irradiated to generate hydrogen peroxide, which is determined by PO-CL detection. 

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