Quality physicochemical methods

Bioassay techniques involve testing rats on antirachitic qualities. An important physicochemical method involves reaction with antimony trichloride. 

A rapid, reliable physicochemical method for predicting the immunologic performance of I-labeled hormones in radioimmunoassays (RIA) has been developed the talc-resin-TCA test. The search for an accurate physicochemical indicator of the quality of a labeled hormone has been undertaken for three decades, " but most techniques have had lim-... 

As stated in section 11.5, methods of polymer HPLC are not absolute. This also holds for the most important one of them, SEC. Therefore, the instraments have to be calibrated or molecular characteristics of analyzed macromolecules that leave the separation column are to be monitored with an independent method (compare sections 11.6.1.4 and 11.7.3.2). Polymers with the known molecular characteristics serve for the colunm calibration. They are called - not always entirely correctly - macromolecular standards. The sets of polymers with different known molar masses and as a rale with low molar mass dispersity are available from several producers. They have been previously characterized with other physicochemical method(s) or just by the independent SEC measurements. In some cases, molecular characteristics of above standards are derived or even only estimated taking into account method of their preparation. As a result, quality of macromo-... 

Tests to monitor the quality of production materials (QC tests) have relied on checking such properties as viscosity, percent solids, sag, pot life, and cure rate, in addition to measuring mechanical properties. The same tests have traditionally been used for receiving inspection procedures by the adhesive user however, there is now interest, particularly in the aircraft industry, to augment these by the use of physicochemical methods of analysis. These newer methods of control are expected to provide information of a more fundamental nature, useful in characterizing adhesives and diagnosing the causes of performance anomalies. 

Y. Jiao, Applications of Modem Physicochemical Methods in Quality Control of Oil , Shipin Keji, 2006, 8, 5. 

Looking at the downstream processing of recombinant pharmaceutical proteins from different sources as a whole, there are more common steps than operations addressing expression system-specific problems or requirements. One of the most important common features is that a given end product must meet the same standards and specifications in terms of safety, quality, potency and efficacy, regardless of the production host. Furthermore, the physicochemical properties of such end products should be identical, so that the intrinsic features used for purification (affinity, hy-drophobicity etc.) are the same. Well-established procedures and protocols should therefore be utilized, and should be adapted to the special requirements of the source material only when absolutely necessary. This is particularly true in the case of pharmaceuticals, since the tendency in this field is to stick to established methods... 

Physicochemical tests are required in essential oil monographs published in standards, pharmacopoeias and codices. Chromatospectral techniques are modern methods used to assess the quality of essential oils. The most important technique for the analysis of essential oils is GC. Several detectors may... 

Supported by the overall development in all fields of analysis during the past few decades, a precise analytical methodology has been developed for the different aspects of quality control, comprising physicochemical, biotechnological, sensory and microbiological methods. In order to meet the sense of the quality control system and by that the customers requirements, all methods applied have to be validated by adequate quality assurance tools. 

Odor and taste quality can be mapped by multidimensional scaling (MDS) techniques. Physicochemical parameters can be related to these maps by a variety of mathematical methods including multiple regression, canonical correlation, and partial least squares. These approaches to studying QSAR (quantitative structure-activity relationships) in the chemical senses, along with procedures developed by the pharmaceutical industry, may ultimately be useful in designing flavor compounds by computer. 

One can remark that plasma polymerization is one of the most promising methods for obtaining the good quality films with broad range of physicochemical properties. 

The main goal of this chapter is to present the theoretical background of some basic chemometric methods as a tool for the assessment of surface water quality described by numerous chemical and physicochemical parameters. As a case study, long-term monitoring results from the watershed of the Struma River, Bulgaria, are used to illustrate the options offered by multivariate statistical methods such as CA, principal components analysis, principal components regression (models of source apportionment), and Kohonen s SOMs. 

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