Compound Acquisition Scheme

The basic heuristic procedure used in this work can be divided into four main activities  

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Fig. 13.5 The compound acquisition scheme. The overall process depicted in the figure provides an efficient procedure for the selection and acquisition of compounds that optimally populate the PRCC with diverse, druglike molecules for suitable screening.

A time-of-flight mass spectrometer (TOFMS) is an excellent instrument for these studies. The TOFMS produces approximately 10 spectra per sec. It is difficult to record individual mass spectra at this rate, but several data acquisition schemes see below) have been developed which record a finite number of discrete spectra. These techniques follow changes in peak intensity over millisecond intervals, thus recording the mass spectra of compounds whose residence time in the ion source is short. 

Figure 2 30 Mass detection scheme in HRMS MID data acquisition. The arrows show the sequence of measurement in the target compound and internal standard data acquisition (legend for the mass scale see Figure 2.229).

The production of potassium bromide discs for IR spectroscopy has never been automated, although at least one scheme has indicated the possibility. When dispersive spectrometers were used, this did not matter so much as spectrum acquisition was of the same order of duration as sample preparation, but FT-IR machines are much more rapid. Thus diffuse reflectance has recently become a very popular technique for monitoring the IR spectra of organic compounds that are soluble in volatile solvents as it only requires the placing of a drop of solution on a sm l layer of ground alkali metal halide powder. 

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