Gas Chromatographic Determination of Micro Amount of Sulfur Dioxide by using Ordinary Temperature Adsorption

Examination was made on the simplified determination of a microquantity of sulfur dioxide in the atmosphere, using ordinary temperature collection and gas chromatngraphy. It was thereby found that the best method of sampling was suctional collection of the air into a Pyrex glass tube filled with 0.5-1g of porous polymer beads (Tenax GC) and suction of the air for 2-4 min at the rate of 20-50 ml/min, at ordinary temperature. For the determination of collected components, the Tenax GC beads are heated to 250°and the gas evolved is introduced into the gas chromatograph equipped with a flame photometric detector, consisting of a seperation column soaked in Chromosorb T filled in a Teflon tube (3.2 mm×2 m), with polyphenyl ether (5 rings) and 0.5 g of phosphoric acid and 12 ml of acetone. Collection of sulfur dioxide by the above method was found to be 100%, and recovery rate was over 95% at the coefficient of variation of 0.6-6%. The limit of detection was ca. 2 ppb with 100 ml of the test air collected. Stability of the sample was good, and there was no loss of sulfur dioxide even when Tenax GC beads were maintained at room temperature for 9 hr. The collection and analytical procedures of this method are simple, require only a short period of time, and analytical precision is good, so that this method is thought to be a useful method for the measurement of a microquantity of sulfur dioxide in the atmosphere. A good result was obtained by comparison of this method with automatic measurement of sulfur oxides in the actual environment.