Analytical biochemistry methods section

In 1961 Braunsberg and James (B17) gave an exhaustive account of the statistical evaluation of methods for estimating adrenocortical steroids and pointed out that very few published methods up to that time had been evaluated in a manner which would pass muster by the orthodox criteria of general analytical chemistry. In this, however, the steroid field is not much worse than other areas of analytical biochemistry, and it is only relatively recently that a serious move to improve precision and quality control in clinical chemistry has gained acceptance. An excellent general review is given by Whitby et al. (W3). In this section I shall cover only certain points which seem to be specifically important in steroid work. 

Many methods exist for the purification of reagents and solvents. A number of these methods are routinely used in synthetic as well as analytical chemistry and biochemistry. These techniques, outlined below, will be discussed in greater detail in the respective sections in this Chapter. It is important to note that more than one method of purification may need to be implemented in order to obtain compounds of highest purity. 

Advances in selenium biochemistry (Arthur, 1994 Heider and Boeck, 1994 Foster and Sumar, 1997 Patching and Gardiner, 1999) and methods for the determination and speciation of the element in biological and environmental samples (Pyrzynska, 1996 D Ullivo, 1997 Thomson, 1998) have been reviewed. In this section, a brief overview of more recent developments in analytical methods and their application to the study of selenium-containing species in biological materials is provided. 

Three general questions about pesticides in agricultural products and the environment must be answered where is it and its metabolites, how much of these are there and what are the metabolites. The Metabolism Section of the Biochemistry Department uses a variety of analytical techniques to answer these questions. Metabolism studies are generally done with radioactive carbon which provides a convenient method for... 

Numerous methods have been developed for assessing the concentrations of FT4 and FT3 in serum. These methods include direct assays that currently serve as reference methods and indirect assays that are more widely available for general laboratory use. The following section describes the principles of these methods and offers some guidelines for their use. The theoretical basis, analytical validity, and clinical utility of these methods have been discussed. Special reports from the Nomenclature Committee of the American Thyroid Association, the National Academy of Clinical Biochemistry, and the NCCLS also review some of the issues and concerns regarding free thyroid hormone measurements. 

Gradient elution chromatography is a separation method that exploits the effect of the fluid phase composition on the retention behavior of the feed components. It is widely used, especially for analytical separations in the areas of the life sciences, in biochemistry, and in the biotechnologies e.g., separation of complex mixtures of proteins or peptides), hi its conventional implementations, SMB units are operated under isocratic conditions. The composition of the fluid phase, e.g., the organic modifier concentration, the pH, or the buffer concentration remain constant in all the sections of the SMB unit. However, it has recently been shown that SMB units can also be operated under solvent gradient mode (SG-SMB). Then, the feed and desorbent streams introduced have a different composition. The fluid phase composition is different in each section. It is chosen independently, in order to... 

Speciation of organometallic compounds containing Au and Ag, on the other hand, was paid only scant attention as a subject for analytical research. The analytical methods that supported research on these compounds had to be dug out from the experimental sections of articles dealing with diverse aspects of chemistry, physics, biochemistry, etc. A review appeared on some of the antiinflammatory drugs shown in Table 1, discussing determination of Au in body fluids and pharmaceutical preparations, and speciation of the compounds and their metabolites. The methods included varieties of atomic absorption spectroscopy (AAS), varieties of neutron activation analysis (NAA), inductively coupled plasma spectrometry combined with mass spectrometric detection (ICP-MS),... 

MALDI), the continuous series of multiply charged macro-ions in ESI-MS reflects charge states and distributions characteristic of the solution structure ( charge structure cf. Section 10.2.1) [31]. Moreover, ESI-MS can be readily carried out with aqueous solutions at physiological solution conditions, enabhng comparative studies with other structure determination methods such as NMR [134]. This feasibility for the direct mass spectrometric characterisation of non-covalent complexes has opened new analytical perspectives for supramolecular chemistry and biochemistry [16, 31, 135]. 

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