環境大気のガスクロマトグラム上に見られる日中に存在し夜間に消滅するピークについて

環境大気サンプリング上の注意

抄録

In the sammer of 1970, a peculier peak was found on the gas chromatograms of ambient air, The peak was present at the day time, but it disappeared at the night. For the present, the peak was named peculier peak A (see Fig. 1, 2, and 3)
Ambient air was sampled on the roof of the Institute of Public Health building by a 200ml glass syringe. After closed by poly-etylene chloride cap, the syringe was carried to the laboratory. Samples were analyzed by gas chromatography within 2 hours.
A U-shape trap filled glass beads was attached to the gas sampling valve on a gas chromatograph. The sampling gas in a 200ml syringe was passed through the trap which was chilled with liquid oxygen. The trap was then brought to 60-80°C by hot water and its contents simultaneously swept into the column. The analytical conditions for the gas chromatograph are shown in Fig. 1 and 2.
Effects on the peculier peak A were researched for sunlight, different sampling syringes, standing time, and sampling method about ambient air. These results show that peculier peak A was formed from slight stain of a syringe with sunlight (see Table 1, 2, 3, 4, and 5).
Further investigations were undertaken to determine effects of balancing gas, the degree of stain of syringes, and light source on peculier peak A. It was confirmed that peculier peak A was remarkably influenced by the stain of human fingers and it was scarcely influenced by balancing gas and poly-ethylene chloride tube. Then, the effect of light source was found to increase in this order: luorescent lamp, tungsten lamp blacklight lamp, infrared lamp, and sunlight. But the intensity and the wavelength distributron of light were not measured (see Table 6, 7, and 8).
Some absorbents and adsorbents were noted to be the other source of peculier peak A. Similar peaks to peculier peak A were found on the some syringes, absorbents, and adsorbents (see Table 10 and Fig. 6).
The identification of peculier peaks was tried from the comparison of retention time and subtractive techniques. The retention data showed that peculier peak A was not alcohols, aldehydes, and ketones and peculier peak B was acrolein or acetone. From the results of subtractive techniques, peculier peak A seemed to be reductant and soluble in water (see Table 9 and Fig. 5).
Note, The magnitude of peculierpeak A was shown the peak height (graduations) on the gas chromatogram chart.