Method Selection Guide

This diagram (Fig. A4) may help in selecting the right ionization method for analysis of a sample by MS. Often, there are several reasonable choices and it is advisable to make the best use possible of what is available at your local facility. MS results also depend on user input. Discuss your options with the MS staff at your facility. 

---

The methods commonly used for the measurement of partitiohoiBafts include the traditional shake-Lask method, HPLCJter-probe, and pH-metric techniques. These methods have been reviewed extensively (Avdeef, 1993). Dearden and Bresnen (1988) axzel Laboratory Procedure (GLP) recommendations on experimental procedures. Hersey et al. (1989) presented a method selection guide. In addition, several methods are available for partition.cissft calculations (Lipinski et al., 1997). 

Table 12.5 Particle size method selection guide... 

Prepare or select guides and standards which assist designers to select proven technologies, parts, materials, methods, etc. 

The physical and chemical properties of stationary phase materials are described in Chapter 3 (including methods for their synthesis) to clarify the differences in similar stationary phase materials supplied from different manufacturers. A detailed selection guide to solvents is given in Chapter 4. The unlimited selection of eluent components and their concentrations is a powerful force in developing separations in liquid chromatography. Although this area seems rather complicated, it is easy to understand the selection of a suitable eluent when you first identify the molecular properties of the analytes and solvents. 

Fig. 14. Selection guide of suitable apoptosis assessment methods based on different cell types and methodologies available in the laboratory. 

Figure 4.9—Selection guide for chromatographic methods with various mobile phases (HPLC. I EC and SEC). The separation method is chosen as a function of the molar mass, solubility and the polarity of the compounds to be separated.

For the less experienced user who is unfamiliar with the method, selection of initial parameters can be daunting. Expert systems have been developed that guide the user and utilize results from successful or failed experiments to move the analyst toward a satisfactory separation. 

Schoenmakers, P. J. In Optimization of Chromatographic Selectivity Guide to Method DevelopmentElscvicr Amsterdam, 1986 pp 119-169. 

Table 4.1, reproduced from Meylan and Howard (1991), lists the 59 bond contributions, and Table 4.2 lists correction factors. These groups and factors when combined, yield the log (base 10) water to air partition coefficient. Table 4.3 compares the two methods and can be used to guide the method selection process. The original paper gives specimen calculations... 

Rule 1. Intended use of the data and the regulatory framework guide analytical method selection. 

On the other hand, conventional control approaches also rely on models, but they are usually not built into the controller itself. Instead the models form the basis of simulations and other analysis methods that guide in the selection of control loops and suggest tuning constants for the relatively simple controllers normally employed [PI, PID, I-only. P-only, lead-lag compensation, etc. (P = proportional, PI = proportional-integral, PID = proportional-integral-derivative)]. Conventional control approaches attempt to build the smarts into the system (the process and the controllers.) rather than only use complex control algorithms. 

Fig. 11.4 Simplified selection guide for choosing an agglomeration method.

To demonstrate the preselection procedure that is based on the aforementioned selection guides, two examples will be presented in Tables 11.2 and 11.3. The evaluations are based on the rankings in Fig. 11.6, and for the elaboration of these examples, the numbers reflecting certain important factors are taken without any adjustment to particular conditions of the two projects. As mentioned before, additional factors could be defined and ranked which take into consideration the special projects and, based on published information or experience, the numbers, indicating responses of different agglomeration methods to these factors, could be modified. Contrary to what has been done in the following, referring to Tab. 11.1, in most cases, the influences of site, supply, and environmental conditions as well as infrastructure considerations should be included. 

A general guide to method selection based on established common applications is provided in Table 8.9. Reasonable solubility in aqueous solution is required for... 

Table 52.3 presents a brief selection guide for different feeding equipments used in drying based on the material characteristics. The information presented in Tables 52.1 through 52.3 is helpful as a general checklist for the preliminary selection of the feed system. Before a final decision is made on the type of equipment, method of operation, initial cost, operating and maintenance costs should be considered. 

Click Next. You will probably now see the Properties Specifications-Data Browser screen. You must select the appropriate physical properties package to predict the equilibrium for your chemical system. There is no choice that is always best. The choice is made through a menu item on the right side labeled Property Method. You may need to click twice to get the conplete menu. This choice is very important (Carlson, 1996 O Connell et al., 2009 Schad, 1998). If you pick the wrong model, your results are garbage. A brief selection guide is given in Table 2-4. 

Simon W and Spichiger UE (1993) Ion-selective membrane phases for microelectrodes. In Kettenmann H and Grantyn R (eds.) Practical Electrophysiological Methods A Guide for in vitro Studies in Vertebrate Neurobiology. New York Wiley. 

Table 7.4 Selection guide to align assessment methods with intended learning outcomes...

The next task required in QSAR development is selection of the best model. Several approaches are used and range from statistically uninformed judgment of the researcher, MAICE, and Mallows s Cp method. Model selection guided solely by the researcher s informal judgment can produce the best model, but consistency of good judgment is enhanced by application of more formal methods. For example, model selection from among candidate models based only on the smallest value will not always produce the best model. 

There are some guidelines and data available from PDS method handbook and OLF standards from Norwegian oil industries (Application of lEC 61508 and 61511 in the Norwegian industries—OLF 70 including appendix A8 and A9 of the same document) some selected guiding points are ... 

Prior experience. Experience provides a good guide to manufacturing method selection, but it is not the best. We tend to stay in the same track because of inertia however, it imperative that each new design be thoroughly analyzed to select the optimum and not the wrong manufacturing method. 

---