Key wordstcd, directed, system, channels, versatile, porous, valves, polymer, packed, analyzer, detectors, light, switching, six, dual, shimadzu, efficient, repeatability, typical, corporation, hydrocarbons, operation, features, valve, detected, simple, chromatograph, chromatograms, easy, good, name, developed, three, technique, columns, separation, based, software, two, concentration, detector, compound, range, information, method, gas, column