An optimized method for airborne peroxyacetyl nitrate (PAN) measurements

• Published in: Journal of atmospheric chemistry 1995-11, Vol.22 (3), p.303-317
• Main Authors: SCHRIMPF, W, MÜLLER, K. P, JOHNEN, F. J, LIENAERTS, K, RUDOLPH, J
• Format: Article
• Language: English
• Subjects: Chemical composition and interactions. Ionic interactions and processes; Earth, ocean, space; Exact sciences and technology; External geophysics; Geophysics. Techniques, methods, instrumentation and models; Meteorology
• ISSN: 0167-7764; 1573-0662
• DOI: 10.1007/bf00696640

We describe a gas-chromatographic method for PAN measurements in the background atmosphere, which has been adapted to the special requirements of aircraft based campaigns. The instrument is installed in a 1.21 m high, 19 inch rack which has a total weight of 70 kg and a power consumption of 750 VA. The gas chromatograph is equipped with a commercial liquid injector and a valve system for injection of gaseous samples. The gas-inlet system allows automatic injection of samples with defined and constant mass, independent from ambient pressure variations. Two different methods are used for calibration: Liquid PAN calibration samples and a diffusion source for gas-phase calibrations. Both methods have reproducibilities better than 90% and agree with each other to better than 85%. An optimum selectivity of the gas-chromatographic separation is obtained by a combination of two short megabore capillary columns of different polarity. The flow rates are 15 cm super(3)/min, the column temperature is 26 degree C. For detection an electron-capture detector, operated at 30 degree C, is used. To allow a reliable control of these relatively low temperatures the instrument is equipped with peltier cooling.