Human behavior efficiency

An efficient system analysis, after all, is only possible whenever one succeeds in incorporating human behavior as well—if possible, expressed in numerical data. Some very successful starts in that direction have already been made. 

Table 13.1 covers general information for different particulates, liquids in gas, typical particles and gas dispersoids, behavior of particles in the human body, charging mechanisms, principles of particle size analysis, methods for particle size analysis, and an estimation of the general collection efficiency of available commercial particle removal equipment. 

The packing material first described for direct injection of biological samples was prepared by simply saturating the accessible adsorption sites of a Cis reversed-phase silica with human plasma proteins (105). After saturation, the human plasma proteins were denatured at the external surface, and their native conformation was destroyed. With this treatment, the proteins formed a hydrophilic layer with weak ion-exchange properties, which provided protection from contact with the sample proteins, whereas the alkyl ligands inside the pores remained unchanged and thus served for analyte retention. The retention behavior of the saturated phase did not alter with this treatment, but the efficiency was reduced dramatically. Such protein-coated columns have shown a lifetime of several months (106). 

COLUMN STABILITY. The absence of a porous support structure results in enhanced column stability at elevated temperature and pH even with micropellicular sorbents prepared from siliceous supports (14). This is illustrated by the chromatogram in Figure 5 which shows the separation of minor conformers of human growth hormone by using a moderately alkaline mobile phase (pH 8.5). Prior to obtaining the above chromatogram, the column was perfused with 4000 column volumes of the mobile phase at 80°C, yet no noticeable changes in retention behavior, separation efficiency and sample recovery had been observed with respect to initial column performance. 

---