264
AUTOMATION OF SOLID-PHASE EXTRACTION
analysis of compounds amenable to this method. The unit is shown 111 Figure 10.9. The details of SPME are discussed in Chapter 12.
10.2.3. Total Automation At least two different configurations to completely automated systems are available for use in the laboratory for solid-phase extraction coupled to instrument operation. The first is the rectilinear configuration with an articulated arm, which is marketed by Sagian (Fig. 10.10). This robot is capable of handling samples, weighing, bar-code reading, and interfacing directly with instruments such as supercritical fluid extraction and GC/MS. The concept of the bench and how one does laboratory work in this configuration of the robot is presented by Majors and Holden (1993). A second approach is the cylindrical robotic system (Fig. 10.11), which is marketed by Zymark. In this system, the robot is most often in the center of the bench and may move around in a circle carrying out the tasks asked of it. They include capping, weighing, centrifuging, filtering, and evaporation. Obviously, SPE is possible with both types of robotic systems. Robotic systems automating the entire method are more costly, often in excess of $100,000 per unit. But for continuous processing of a specific method, they could be cost effective. Furthermore, these units could be interfaced to other less expensive automated SPE units and work in conjunction with them for the entire analysis.
Figure 10.10. Schematic of a rectilinear robotic application. [Reprinted with permission from LC-GCmagazine, from Majors and Holden (1993)].