Global Gas Chromatography Columns Market By Type (Wall Coated Open Tubular (WCOT) , Surface Coated Open Tubular (SCOT) , and Fused Silica Open Tubular (FSOT)), By Application (Hydrocarbon and Petrochemical , Pharmaceutical Industry , Environmental , and Biochemistry), By Region, and Key Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2020-2029