Implementation strategy selection generally

The above discussion concerns selected applications and physical parameters but it illustrates the general implementation strategy for physical chemosensors. 

From the perspective of a generalized analytical or preparative purification strategy, it is obviously desirable to select chromatographic conditions in which the In k at f (or In (1 /[ C, ])) retention dependencies approximate case a or case b, rather than cases c and d. For the latter two cases the KassoCj, of the biosolute for the stationary phase is obviously too high, the desorption window suitable for elution is too narrow, and the mass (or bioactivity) recovery potentially is at risk. However, with crude feed stocks implementation of the case a or d scenario should not necessarily be excluded out of hand from a selectivity point of view. For example, situations have been... 

Moreover, the effect of pH on a particular compound s retention needs to be determined first before exploring the retentivity and selectivity of different columns. The strategy and choice of the optimal pH for analysis was discussed in Chapter 4 and is further reinforced in the case studies within this chapter. After the optimal pH is chosen for the separation and the gradient has been optimized on a particular column and the optimal selectivity still has not been achieved between critical pairs, then a column screening can be performed. For method column screening, generally columns with 10-cm or 5-cm X 3.0-mm i.d. could be used that are packed with 3-pm particles. Implementation of a column switcher that can use six different types of stationary phases such as two types of C18 from different vendors, phenyl, two polar embedded, and pentafluorphenyl is suggested. 

Remedy selection involves three principal steps i) development of an overall exposure control strategy (i.e., what to do), ii) selection of optimal remediation technologies to implement this strategy (i.e., how to do it), and iii) development of appropriate design and construction specifications. The general decision process for remedy selection is described in further detail below. 

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