Solid phase extraction guidelines

B. A. Bildenmeyer, Guidelines for proper usage of solid-phase extraction devices, LC, 2 578 (1984). 

EPA EPA Chemical QC Guidelines EPA method 539 Determination of hormones in drinking water by solid phase extraction (SPE) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS) [77]... 

TABLE 6-10. Separation Guidelines for Solid-Phase Extraction... 

Most of the experimental applications of the ZLC technique have been with gaseous systems, and for these systems the technique may now be regarded as a standard method. Based on our experience it is possible to suggest some guidelines as to how the experiments should be carried out. The key parameter is L, which from its definition (Eq. 17) can be considered the ratio of the diffusional and washout time constants R /D and KVs/F. This parameter is also equal to the dimensionless adsorbed phase concentration gradient at the surface of the solid at time zero. From either of these definitions it is evident that L gives an indication of how far removed the system is from equilibrium control. This parameter is proportional to the flow rate, so it can be easily varied, and to extract a reliable time constant, it is necessary to run the experiment at at least two different flow rates. 

---