On-line analyzer for VOCs and method of using the same

An on-line analyzer for VOCs in gas comprising:

• a sampling device;
• a gas-supply device;
• and
• a refrigerating device connected to the sampling device and the gas supply device respectively,
• wherein the on-line analyzer for VOCs uses two cryo-focuses in empty tubes and two detectors, also comprises:
• a gas flow control device connected to the sampling device and the gas supply device respectively;
• an analyzing device connected to the gas flow control device;
• and
• a data acquisition and processing device connected to the analyzing device,
• wherein the sampling device comprises:
• a 6-way valve;
• and
• a filter, an inlet tube for internal standards, an inlet tube for external standards, a first solenoid valve and a second solenoid valve which are connected to the 6-way valve respectively,
• wherein the first solenoid valve is connected to the second solenoid valve,
• wherein the refrigerating device comprises:
• a 12-way valve;
• and
• a first dewatering tube, a second dewatering tube, a first concentrating tube and a second concentrating tube connected to the 12-way valve respectively,
• wherein the first dewatering tube and the second dewatering tube are connected to the second solenoid valve simultaneously,
• wherein the refrigerating device also comprises a trapping tube for CO2,
• wherein the second dewatering tube is connected to the 12-way valve through the trapping tube for CO2,
• wherein the first dewatering tube, the second dewatering tube, the first concentrating tube and the second concentrating tube are disposed in a cryotrap.