Analytical methodology, general

The experimental and analytical methods used in the numerous other reports cited in this chapter should be consulted directly if it is of use. Here, 1 provide a brief summary of the experimental and analytical methodology generally used for the studies discussed here as examples. 

Caustic soda solutions are normally tested for general alkalinity and percentages of NaCl, Na2S04, and NaClO as weU as for Fe and Ni levels. The general methods are outlined in Table 22. Detailed analytical methodologies are available from the major caustic soda suppHers. 

Although low levels of methylxanthines have been detected in the leaves and flowers of T. cacao, the primary storage location is within the seed or bean.16 The cocoa bean is the major natural source of the methylxanthine theobromine, but contains only small amounts of caffeine. Theophylline has been detected in cacao beans, but at such low concentrations that its presence generally is ignored. Together, theobromine and caffeine account for up to 99% of the alkaloid content of T. cacao beans. Alkaloid content is affected by genetic makeup, maturity of beans at harvest, and fermentation process. Analytical methodology also is partially responsible for some of the disparity in methylxanthine values since many early methods were unable to separate theobromine and caffeine. 

For a proper understanding of the protein binder s function in artworks and historical building materials, it is essential to identify the individual proteinaceous additives and to distinguish them even in materials where they are present in very small amounts, in insoluble forms and often in matrices unsuitable from an analytical point of view. For many materials the appropriate analytical methodology has not been found up to now and, in general, this type of analyses has not become a routine technique. Thanks to the recent development of proteomics (Section 6.2) most of the afore-mentioned problems have been resolved mass spectrometry forms a fundamental platform for this new methodology. 

Should a 24-h sample be collected or does a random (spot) sample suffice Our methodologies generally utilize a form of precursoriproduct ratio for the diagnosis of most conditions so we are satisfied with random collections. However, it is important that for certain analytes accurate quantification is achieved, which requires 24-h sample collection. Cases in point would be the excretion of unconjugated cortisol and related compounds, and the measurement of tetrahydroaldosterone (THAldo) required for the diagnosis of mineralocorticoid-related conditions. 

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