@article{JRC4005,
	address = {},
	year = {1985},
	author = {De Bortoli M and Pecchio E},
	abstract = {TRACER EXPERIMENTS ARE USED INCREASINGLY IN DIFFERENT COUNTRIES TO DESCRIBE     TRAJECTORIES OF AIR MASSES,ESPECIALLY FOR POLLUTION CONTROL STUDIES.            IN THE LAST YEARS THE NEED TO FOLLOW UP TRACED PLUMES FOR DISTANCES OF          SEVERAL HUNDRED KILOMETERS HAS MOTIVATED RESEARCH FOR NEW TRACERS, HAVING A     FAVOURABLE BALANCE BETWEEN COST OF THE RELEASED TRACER AND QUANTITY NECESSARY   TO PRODUCE A MEASURABLE CONCENTRATION AT THE DESIRED DISTANCE.                  THE PERFLUORINATED DERIVATIVES OF SOME CYCLIC HYDROCARBONS HAVE PROVED          EXCELLENT FEATURES IN THIS RESPECT BECAUSE OF THEIR VERY LOW BACKGROUND         CONCENTRATION IN THE ATMOSPHERE AND OF THEIR HIGHLY SENSITIVE GC-ECD            MEASUREMENT.                                                                    THIS PAPER REPORTS ON THE DEVELOPMENT OF A SIMPLE METHOD FOR THE DETERMINATION  OF TWO PERFLUOROCARBONS PERFLUOROMETHYLCYCLOHEXANE (C7F14) AND PERFLUORODI-     METHYLCYCLOHEXANE (C8F16) DOWN TO 5X 10-14 VOLUME FRACTION IN AIR (0.05 PPT).   THE METHOD INVOLVES THE FOLLOWING STEPS:                                        A) SAMPLING OF 5-10 L OF AIR ON A 160X6MM (3MM I.D.) COLUMN, CONTAINING 200 MG     OF GRAPHITIZED CARBON BLACK.                                                 B) DESORPTION FOR 6 MIN AT 250 C IN A SMALL OVEN.                               C) CRYOGENIC TRAPPING AT -100 C IN A FUSED SILICA CAPILLARY.                    D) INJECTION IN THE GC BY FLASH HEATING OF THE CAPILLARY.                       FOR THE DESORPTION TO INJECTION STEPS A COMMERCIALLY AVAILABLE APPARATUS HAS    BEEN USED, WHICH HOWEVER HAD TO BE IMPROVED IN SEVERAL ASPECTS.  MORE LIMITED   EXPERIENCE ON A SIMILAR INSTRUMENT, PRODUCED BY A DIFFERENT FIRM, BUT NOT YET   COMMERCIALLY AVAILABLE IS ALSO REPORTED.                                        THE GC ANALYSES ARE CARRIED OUT USING AN APOLAR (METHYLSILICONE) CAPILLAR       COLUMN AT SUBAMBIENT TEMPERATURE.                                               THE FOLLOWING ASPECTS OF THE DETERMINATION HAVE BEEN STUDIED FOR OPTIMIZATION   PURPOSES.  TWO ADSORBANTS HAVE BEEN TESTED, I.E. CARBON MOLECULAR SIEVE AND     GRAPHITIZED CARBON BLACK: THE LATTER HAS BEEN FOUND TO GIVE MORE                REPRODUCIBLE RESULTS, TO REQUIRE A SHORTER DESORPTION TIME AND TO ADSORB        MUCH LESS WATER VAPOUR WHICH MAY CAUSE CLOGGING OF THE CAPILLARY TRAP.  THE     EFFECTIVENESS OF PERMEATION DISTILLATION DRYING TUBES IN DRYING AMBIENT AIR     BEFORE ADSORPTION ON THE TRAP, THE BREAK THROUGH VOLUME OF THE SAMPLING         COLUMN AND THE DESORPTION TIME HAVE ALSO BEEN STUDIED.                          
		},
	title = {Sensitive Determination of Perfluorocarbon Tracers in Air by Intermediate Trapping and GC-ECD Analysis},
	type = {},
	url = {},
	volume = {8},
	number = {},
	journal = {Journal of High Resolution Chromatography & Chromatography Communication},
	pages = {421-426},
	issn = {},
	publisher = {},
	doi = {}
}