Qualitative analysis strategies

In qualitative analysis, the goal is to establish the identity of unknown components in the sample.2,4 5 In HPLC, peaks are identified by its retention time as compared with those of the known analytes in the standard solution. Since absolute retention times are affected by many parameters, relative retention times (RRT) (retention time ratio against a reference component) are often used in more complex samples. Spiking the sample with known analytes is another useful technique to establish peak identity. Other techniques include  

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Coudert, O., Madre, J., Hemi, F. New Qualitative Analysis Strategies in Metaprime. In Annual Reliability and Maintainability Symposium, Anaheim, CA, USA, pp. 298-303 (1994)... 

For those errors with significant consequences where recovery is unlikely, the qualitative analysis concludes with a consideration of error reduction strategies that will reduce the likelihood of these errors to an acceptable level. These strategies can be inferred directly from the results of the PIF analysis, since this indicates the deficiencies in the situation which need to be remedied to reduce the error potential. 

Precipitation reactions have many applications. One is to make compounds. The strategy is to choose starting solutions that form a precipitate of the desired insoluble compound when they are mixed. Then we can separate the insoluble compound from the reaction mixture by filtration. Another application is in chemical analysis. In qualitative analysis—the determination of the substances present in a sample—the formation of a precipitate is used to confirm the identity of certain ions. In quantitative analysis, the aim is to determine the amount of each substance or element present. In particular, in gravimetric analysis, the amount of substance present is determined by measurements of mass. In this application, an insoluble compound is precipitated, the precipitate is filtered off and weighed, and from its mass the amount of a substance in one of the original solutions is calculated (Fig. 1.6). Gravimetric analysis can be used in environmental monitoring to find out how much of a heavy metal ion, such as lead or mercury, is in a sample of water. 

When a precipitate has been formed during the qualitative analysis of the ions present in a solution, it may be necessary to dissolve the precipitate again to identify the cation or anion. One strategy is to remove one of the ions from the solubility equilibrium so that the precipitate will continue to dissolve in a fruitless chase for equilibrium. Suppose, for example, that a solid hydroxide such as iron(IIl) hydroxide is in equilibrium with its ions in solution ... 

Wherever possible, a qualitative analysis of equations must precede numerical simulation. However, particularly for dimensions greater than 2, it is not always possible to carry out a complete analysis without a computer. Therefore a tendency has recently developed to apply numerical calculations to "guess qualitative peculiarities. A reasonable strategy for complicated cases is to combine numerical experiments and their "qualitative interpretation. 

Finally, we point out the efficacy of higher order strategies in fluorescence analysis. We have shown that when the dimension of pH is added to the simultaneous analysis of warfarin and 7-OH warfarin an improvement in quantitation results. Other dimensions may be added as well, for example, a series of excitation emission matrices may be recorded as a function of chromatographic retention time, time after delta-function excitation, or as a function of concentration of an added quencher. New strategies will be required to analyze such large multi-dimension data sets, but the benefits will be even larger--the quantitative and qualitative analysis of ever more complex mixtures. 

Analysis of simulated flow results. The solution process generates huge amounts of data about the simulated flow process (flow, species and temperature fields within the solution domain). With large numerical simulations, one may become lost in the sea of numbers in the absence of appropriate tools to analyze the simulation results. Appropriate analysis strategies and tools to implement these strategies must be developed to draw useful conclusions about the flow process under consideration. Some ways of identifying key flow features, such as vortices, are also useful for qualitative evaluation of simulation results. Methods and tools for error analysis and for validation are also essential to derive maximum information from the simulation results and to plan further studies. 

Risk analysis, while it can employ scientific methodologies, is very much based in the experiences of those involved in undertaking the analysis, and, where qualitative analysis is undertaken, by the data used in the assumptions made about likelihood and consequences of events. Therefore, as discussed in Chapter 1, the high degree of uncertainty inherent in most risk analyses means that the results are most useful for comparing alternate strategies— not for coming up with an unequivocal measure of risk. 

A qualitative analysis of the features that play relevant roles in RD design result in the definition of an integrated strategy. This approach -termed multiechelon approach and extensively described in chapter 4- combines systematically the capabilities and complementary strengths of available graphical and optimization-based methods. 

Simplified strategy of qualitative analysis in Mdssbauer spectroscopy (i. and n.i. stand for informative and not informative, respectively)... 

FIGURE 1 Simplified strategy for separation of cations into groups for qualitative analysis. 

Nowadays, the most common approach to qualitative analysis is examination of the isolated surfactant by molecular spectroscopy IR, NMR, and MS analyses. The result of this examination is normally sufficient to tell whether the surfactant fraction is pure and what classes of compounds are present. Further analytical strategy is developed based upon this information. 

Fire Protection FIVE and FRANC support quantitative and qualitative fire risk, assessmeiil. FRANC also supports the analysis of alternative safe shutdown paths during an Appendix R review. System train availability is exhibited on a system status panel, Using this a strategy can be defined to upgrade Thcrnm 1. if identify risk significant areas. 

The following techniques can be used to collect data about human performance in CPI tasks and provide input to task analysis methods described in Section 4.3. These data can include process information critical for the task, control strategies used by the workers, diagnostic plans etc. A distinction can be made among data collection methods that provide qualitative data (such as interviews, observations, and sources of documentation) and methods that can be used to measure aspects of performance (such as activity analysis, simulations, and information withholding). The latter methods can provide more precise data which can be quantified. 

The qualitative human error analysis stages described above are applied to the task steps in subtask 3.2. Examples of the results of this analysis are shown in Figure 5.8. The corresponding error-reduction strategies are shown in Figure 5.9. 

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