one 6-port two-position injection valve (www.vici.com)
and one 8-position selection valve (www.vici.com, not in use in this study).
The system was controlled by specially designed hardware and Labview software (www.ni.com)
A more detailed description of the system is not possible at this time, due to its patent pending status
The operation of the system is depicted in Fig. 1, and described briefly below (the abbreviations used in Fig. 1 were bracketed).