Biological materials, analysis histor

When ammonia is found in biological materials at physiological pH (7.2), most of it (99%) will be found as ammonium ion, due to its pK of 9.2. This is an important consideration for any subsequent analysis. The determination of ammonia (as dissolved NH3 and ammonium ion) in blood, plasma, or semm is of value in detecting existing or impending hepatic coma and Reyes Syndrome (Meyerhoff and Robins 1980 Tietz 1970). The determination of ammonia in urine had historically been used as an indicator of the kidney s ability to produce ammonia however, this procedure has been replaced by more modem and accurate tests for kidney function. Procedures for the determination of ammonia in biological samples are found in Table 7-1. Ammonia is also tested for in calculi (abnormal concretions in the body formed of mineral deposits, often found in the gall bladder, kidney, or bladder) (Tietz 1970) however, this is not a quantitative test and is not included in Table 7-1. 

Reliable evaluation of the potential for human exposure to CDDs depends in part on the reliability of supporting analytical data from environmental samples and biological specimens. Historically, CDD analysis has been both complicated and expensive, and the analytical capabilities to conduct such analysis have been available through only a relatively few analytical laboratories. Limits of detection have improved greatly over the past decade with the use of high-resolution mass spectrometry, improvements in materials used in sample clean-up procedures, and with the use of known labeled and unlabeled chemical standards. Problems associated with chemical analysis procedures of CDDs in various media are discussed in greater detail in Chapter 6. In reviewing data on CDD levels monitored or estimated in the environment, it should be noted that the amount of the chemical identified analytically is not necessarily equivalent to the amount that is bioavailable (see Section 2.3) and that every measurement is accompanied with a certain analytical error. 

Polymers can be classified in different ways. From the forensic perspective, a reasonable starting point is to divide pol)Tmers into biologically derived polymers (biopol3rmeis) and synthetic organic polymers. Biopolymers are extracted from natural sources such as plants or animals. Even though proteins and DNA are biopolymers of unquestioned importance in forensic science, their analysis resides in the context of forensic biology. The biopolymer we will concentrate on is cellulose, the base material in paper and cotton fibers. Historically and chemically, semisynthetic polymers fall between naturally derived and synthetic polymers. Rayon and cellophane are made from regenerated... 

Underlying these issues is the crucial historical context which has done so much to shape perceptions about CBW. The first part of this book is therefore concerned with the history of chemical warfare up to the present day. The second part discusses contemporary problems - the threat, modernisation of the US CW capability and arms control. My primary concern is with chemical rather than biological weapons, but because of the close relationship between the two -despite their many differences - the subject of BW is also touched upon. The remainder of this chapter attempts to provide some basic but essential definitions and facts about CBW. This material is included here in the first chapter because it is fundamental to a proper analysis of the subject and an appreciation of the issues. 

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