Determination of Iodine, Bromine, and Chlorine in Atmospheric Samples by Neutron Activation Analysis

Abstract

Iodine, bromine, and chlorine are determined by pile neutron activation in aqueous atmospheric samples. About 8 ml. of aqueous sample are irradiated, short-lived 88 C1, 80 Br + '"»Br and 128 I are separated using carriers, selective oxidation and reduction, and CC1 4 extraction, and beta radioactivity is counted from solid silver halide sources. Six or seven samples per day can be analyzed with 5% accuracy. Zusammenfassung Jod, Brom und Chlor werden mit Hilfe der Neutronenaktivierung von atmosphärischen wässerigen Proben im Reaktor bestimmt. Man bestrahlt etwa 8 ml der wässerigen Probe, trennt die kurzlebigen Isotope S8 C1, 80 Br, 80m Br und 128 J mit Trägern, selektiver Oxydation/Reduktion und CCl 4 -Extraktion ab und zählt die ^-Aktivität festen Silberhalogenids. 6 bis 7 Proben im Tag können mit 5% Genauigkeit analysiert werden. Résumé Iode, brome et chlore sont déterminés par activation neutronique d'échantillons aqueux atmosphérique dans un réacteur. La solution aqueuse (~ 8 ml) est irradiée, les isotopes à vie courte: 88 C1, 80 Br, 80m Br et 128 I sont séparés à l'aide d'entraîneurs par oxydoréduction sélective et par extraction par CC1 4 . On compte finalement l'activité β des halogénures d'argent solides.On peut effectuer jusqu'à 6-7 analyses à 5% de précision par jour.Brought to you by | provisional account Unauthenticated Download Date | 6/11/15 1:10 PM

Iodine, bromine, and chlorine in the Hawaiian marine atmosphere

“…The analytical procedure, reported in detail elsewhere [Duce and Winchester, 1965], is based on neutron activation analysis. Irradiating the aqueous sample with neutrons in a nuclear reactor produces radioactive 37.3-rain C138, 18-min BF ø, 4.5-hr Br 8øm, and 25-min I •.…”

Particle Size Distribution of Chlorine and Bromine in Mid-Continent Aerosols From the Great Lakes Basin.

“…Since the contours are logarithmically spaced, we can estimate the mean travel distance of aerosol Cl to be about 200 km near the coast to 1000 km far from the coast. If air masses move 400 km/day (5 m/sec), an atmospheric residence time of (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) x 104 sec is implied. A single mean deposition velocity of 1 cm/sec would account for this range of residence times if the mean altitude for atmospheric Cl varied from 159 400 m near the coast to 2000 m inland.…”

“…Within these limitations, the effective particle radius ranges represented by the data of Figure D-1 are given in Table D -1 ( 2,9.19). following a radiochemical separation step (5). In Figure D presented else#here (17).)…”

“…GR:II,3,4,5, and 6:EE:III). Moreover, in Run 5:EE:III, only 15% of the air sampled would have had recent injection of marine aerosols and the Cl concentration in the giant particles was correspondingly reduced in comparison with Runs 3, 4, and 6:EE:III (Figure 12).…”

“…Assuming uniform mixing to an altitude of 2 km and an average wind speed of 10 m/sec, this is equivalent to a resultant transport of 5 kg Cl/ (m-day). As both these estimates may underestimate storm conditions which en-hance sea salt transport inland, we choose 1 5. times Eriksson's estimated flux of chloride and apply it along a projected windward coastline of 4000 km to ob-152 tain 7 x 10 g Cl/yr as an upper bound for the annual natural Cl input over 12 < the continental United States.…”