Environmental analysts

A survey on trends of sample preparation (SP) revealed that pharmaceutical and environmental analysts are more likely to employ sample preparation techniques [16]. Figure 2.2 shows various sample preparation steps that may be employed in sample preparation. Most analysts use 1 to 4 steps for sample preparation however, some can use more than 7. Interestingly, a large number of analysts have to perform analyses of components in the parts-per-million range or below. 

Therefore, in this chapter we describe major refinery operations and the products therefrom and focus on their composition, properties, and uses. This presents to the reader the essence of petroleum processes, the types of feedstocks employed, and the product produced, as well as warning of the types of the chemicals that can be released to the environment when an accident occurs. Being forewarned offers an environmental analyst the ability to design the necessary test methods to examine the chemical(s) released. It offers environmental scientists and engineers the ability to start forming opinions and predictions about the nature of the chemical(s) released, the potential effects of the chemical(s) on the environment, and the possible methods of cleanup. 

Although it may be felt that environmental analysts must, by definition, focus on analysis of refinery products and wastes, knowledge of the various environmental regulations (Table 5.1) is always helpful in determining the analyses that must be performed. 

It is at this point that the environmental analyst has to identity the natme of the chemicals and their potential effects on the ecosystem(s) (Smith, 1999). Although petroleum itself and its various products are complex mixtures of many organic chemicals (Chapters 2 and 3), the predominance of one particular chemical or one particular class of chemicals may offer the enviromnental analyst or scientist an opportunity for the predictability of behavior of the chemical(s). 

Putting in time and effort up front wiU help any environmental analysts to find a way throngh the method validation maze and eliminate many of the problems common to inadeqnately validated analytical methods. 

The data obtained by the analysis have become key remediation criteria and it is essential that the environmental analyst (and others who may use the data) be knowledgeable about the various analytical methods. It is also important to know that minor method deviations may be found from region to region. For example, in terms of nomenclature, itself a complex and often ill-defined area of petroleum science (Chapter 1) (Speight, 1999), the analytical methods may refer to total petroleum hydrocarbons as mineral oil, hydrocarbon oil, extractable hydrocarbon, and oil and grease. 

The importance of residua and asphalt to the environmental analyst arises from spillage or leakage in the refinery or on the road. In either case, the properties of... 

Pollution prevention options are usually subdivided into four areas (1) good operating practices, (2) processes modification, (3) feedstock modification, and (4) product reformulation (Lo, 1991). The options described here include only the first three of these categories since product reformulation is not an option that is usually available to the environmental analyst, scientist, or engineer. 

Remarkably, the class of chlorinated paraffins has not received much attention, while the worldwide production surpasses by far that of PCBs and substantial environmental levels are being reported. The enormous complexity of the mixture with tens of thousands of congeners may be one of the reasons for that. Environmental analysts have been deterred by this complexity, which demands qualitative and quantitative methods at a level beyond the performance characteristics of their instruments. However, now the selectivity and sensitivity of analytical instruments are improving rapidly and have reached performance levels that were previously unthought-of. That brings a reliable analysis of chlorinated paraffins within reach, though it is still not easy. 

However, reversed-phase chromatography is not just suitable for polar compounds alone. For example, the seventeen polycyclic aromatic hydrocarbons which are referred to by environmental analysts as priority pollutants can be completely separated within 15 min, as shown in Fig. 10.13. Figure 10.14 shows the separation of the complex mixture of aromatic gasoline components with a highly resolved elution pattern usually only expected from capillary gas chromatography. 

The analysis of many priority pollutants in soil, sludge, and water matrices begins with an extraction of the sample by DCM. Consequently, any method that is compatible with a sample already preconcentrated in DCM should be of particular interest to the practicing environmental analyst. 

Environmental analysts have focused their attention in developing and modifying monitoring methods for routine control of sulfur dioxide and hydrogen sulfide in gas phase/air, sulfide in natural waters and sediments and sulfite in urban wastewaters, industrial discharges, processed food, and beverages. 

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