| 摘要 |
PURPOSE:To estimate a pollution state and to perform an accurate measurement of gas, by carrying out a back flush of a gas chromatography and removing a pollutant of a flow passage and valve between a gas bomb and a column, and then, measuring a peak eluted collectively. CONSTITUTION:In a measuring apparatus flowing carrier gas in a column 6 in a reverse direction by switching a step 1 of a flow passage shown by a dotted line 4 which is provided with a switching valve 4, to a step 2 of the flow passage shown by a solid line and sending nonmethane hydrocarbons to a gas detector (FID) 9 to measure said hydrocarbons, water is introduced into the carrier gas in a column 6 in an early stage of analysis and steam is passed through the column 6. Next, the carrier gas flows in the column 6 in a reverse direction from the early stage by the flow passage step 2 shown by a dotted line and a peak eluted collectively is measured and a pollutant of the column 6, the flow passage of the carrier gas in the upper stream side of the column and a pressure control valve 2, are measured by the FID9. The pollution is estimated by using this result and the accurate analysis is carried out by correcting the measured value of nonmethane hydrocarbons. |
