Analysts’ roles

The critical role of analysts introduces a potential for bias that overrides all others—the an ysts evaluation of the plant information. Analysts must recognize that the operators methods, designers models, and control engineers models have merit but must so beware they can be misleading. If the analysts are not familiar with the unit, the explanations are seductive, particiilarly since there is the motivation to avoid antagonizing the operators and other engineers. 

Enantiomeric separations have proven to be one of the most successful applications of packed column SEC. Despite initial reluctance, many analysts now use SEC routinely for both analytical and preparative chiral separations. Additional studies of chiral recognition in SEC and continued improvements in instrumentation will ensure a prominent role for SEC in chiral separations methodology in the future. 

In many analyses, fhe compound(s) of inferesf are found as par of a complex mixfure and fhe role of fhe chromatographic technique is to provide separation of fhe components of that mixture to allow their identification or quantitative determination. From a qualitative perspective, the main limitation of chromatography in isolation is its inability to provide an unequivocal identification of the components of a mixture even if they can be completely separated from each other. Identification is based on the comparison of the retention characteristics, simplistically the retention time, of an unknown with those of reference materials determined under identical experimental conditions. There are, however, so many compounds in existence that even if the retention characteristics of an unknown and a reference material are, within the limits of experimental error, identical, the analyst cannot say with absolute certainty that the two compounds are the same. Despite a range of chromatographic conditions being available to the analyst, it is not always possible to effect complete separation of all of the components of a mixture and this may prevent the precise and accurate quantitative determination of the analyte(s) of interest. 

Quantitative methodology employing mass spectrometry usually involves selected-ion monitoring (see Section 3.5.2.1) or selected-decomposition monitoring (see Section 3.4.2.4) in which a small number of ions or decompositions of ions specific to the compound(s) of interest are monitored. It is the role of the analyst to choose these ions/decompositions, in association with chromatographic performance, to provide sensitivity and selectivity such that when incorporated into a method the required analyses may be carried out with adequate precision and accuracy. 

Byrne AR (1992) Some consideration regarding reference materials and their role in environmental monitoring. Analyst 117 251-258. 

Theoretically IQC should be the front-line approach to quality. If a method has been adequately validated and shown to meet the requirements of the user and kept in analytical control with IQC to detect intrusion of bias or imprecision, then the EQA needs to provide the occasional, independent, objective reassurance. In practice however, the EQA is likely to play an equal role with IQC, both in confirming problems brought to the attention of the analyst by the IQC and in stimulating further action. 

The chromatographic and mass spectrometric choices facing the analyst in coupling SFC and MS successfully, namely injection method column type of flow restrictor and mass spectrometer ionisation method and type of vacuum system, have been described [398]. In SFC-MS coupling, the restrictor plays a major role, as the expansion behaviour to a large extent determines the overall performance of the SFC-MS system and defines the range of applications. 

The goal of EDA is to reveal structures, peculiarities and relationships in data. So, EDA can be seen as a kind of detective work of the data analyst. As a result, methods of data preprocessing, outlier selection and statistical data analysis can be chosen. EDA is especially suitable for interactive proceeding with computers (Buja et al. [1996]). Although graphical methods cannot substitute statistical methods, they can play an essential role in the recognition of relationships. An informative example has been shown by Anscombe [1973] (see also Danzer et al. [2001], p 99) regarding bivariate relationships. 

The role of the analytical chemist has not changed since the time analysts discovered that naturally occurring products were composite materials. For example,... 

After five years as an analyst, Vicki moved within LGC to work on the DTI-funded Valid Analytical Measurement (VAM) programme. In this role, she was responsible for providing advice and developing guidance on method validation, measurement uncertainty and statistics. One of her key projects involved the development of approaches for evaluating the uncertainty in results obtained from chemical test methods. During this time, Vicki also became involved with the development and delivery of training courses on topics such as method validation, measurement uncertainty, quality systems and statistics for analytical chemists. 

The rate of a chemical reaction and the extent to which it proceeds play an important role in analytical chemistry. The fundamental problem which faces the analyst arises because thermodynamic data will indicate the position of equilibrium that can be reached, but not the time taken to reach that position. Similarly, a compound may be thermodynamically unstable because its decomposition will lead to a net decrease in free energy, whilst a high activation energy for the decomposition reaction restricts the rate of decomposition. In practical terms such a compound would be stable, e.g. NO. It is thus essential to consider all analytical reactions from both thermodynamic and kinetic viewpoints. 

If they are not software people, your role as analyst is to interpret between them and the formal models. The models represent your team s clear understanding of what you are to provide. By writing them, you are taking the fuzzy and inconsistent desires of the client, crystallizing them into a more precise form, exposing the questions you need to ask, and going back to the client with questions, scenarios, storyboards, proactive proposals of precise definitions of terms and requirements, and prototypes (see Figure 5.1). The cycle con-... 

Since the interaction of the mixture components with the liquid stationary phase plays the key role in the separation process, the nature of the stationary phase is obviously important. Several hundred different liquids useful as stationary phases are known. This means that the analyst has an awesome choice when it comes to selecting a stationary phase for a given separation. It is true, however, that relatively few such liquids are in actual common use. Their composition is frequently not obvious to the analyst because a variety of common abbreviations have come to be popular for the names of some of them. Table 12.3 lists a number of common stationary phases, their abbreviated names, a description of their structures, and the classes of compounds (in terms of polarity) for which each is most useful. 

Thus, and to reaffirm earlier statements, there is no single analytical method that is perfect or even adequate for all cases to determine the amount of total petroleum hydrocarbons in a sample. Different analytical methods have different capabilities, and (this is where the enviromnental analysts plays an important role) it is up to the analysts to demonstrate that the method applied at specific sites was appropriate. 

Despite some distinct advantages of CE for pharmaceutical analysis, the current number of pharmacopoeial monographs which prescribe CE is rather limited. Although it is difficult to point out the exact reason for this, an appropriate training for pharmaceutical analysts in CE-specific analytical characteristics certainly plays an important role. We do hope that this book may provide a contribution in this respect. 

Taylor et al. [20] have paid considerable attention to the changing role of management, particularly with regard to the introduction of robotic systems. Management has the responsibihty to define the best areas for automation in terms of cost-effectiveness and probabihty of success. Without adequate resources, a project will fail. Laboratory managers must act as the interface between senior management and analysts to ensure that the appropriate incentives, resources and education are made available. 

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