Some simple methods for determination of Cs-137 in sea water

U radu je prikazana »batch« metoda odvajanja Cs-137 iz morske vode jednokratnom obradom amonijevim fosfomolibdatom i nova brza metoda separacije Cs-137 natrijevim trifenilcianoboratom (Na TPCB-Cezignost). Sastav spoja NaTPCB je točno definiran, što omogućuje određivanje kemijskog iskorištenja. Svi uzorci su brojeni 256-kanalnim analizatorom i kristalom NaJ/Tl, 1OOX1OO mm.Cs-137 can easily be recovered from sea-water by a batch method based on the treatment with NH4-phosphomolybdate (AMP). The method has been conveniently applied for the separation of Cs-137 in the Adriatic. Another method for a quick separation of Cs-137 from sea-water by precipitation with Na-triphenylcyanoborate (NaTPCB-Cesignost) is described. The chemical yield was obtained by weighing the precipitate. Gamma spectra of all samples were measured on a 256-channel analyser with a NaJ/Tl 4 X 4" crystal

Separation of La-140 from for age samples by NH4-cinnamate

U radu je prikazana nova metoda za odvajanje La-140 od Ba-140 u uzorcima sijena i lucerke u svježim uzrocima fallouta. Primijenjena je amonijeva sol cimetne kiseline.NH4-cinnamate was tested as a reagent for the precipitation and separation of La-140 from forage samples. The precipitate is crystalline, easily filterable, thermically stable, and seems to be a convenient reagent for radiochemical separations. The final precipitate has a formula La(C6H5CH = CHCOO)3

Review of analytical methods for determination of stable and radioactive cesium

Prikazane su metode za određivanje aktivnog cezija radiokemijskim metodama ili stabilnog cezija u tragovima, analitičkim metodama. Posebna pažnja obraćena je metodama određivanja Cs-137 u uzorcima biosfere. Sakupljena literatura odnosi se na radove objavljene u posljednjih pet godina, Od starijih publikacija navedeni su prikazi ili izvorni radovi koji su temelj većini metoda koje se danas upotrebljavaju.A number of radiochemical methods for determination of active cesium and some analytical methods for determination of stable cesium are described. Particular attention is paid to the methods for determination of Gs-137 in samples of biosphere. The literature listed relates to papers published in this field in the past 5 years and to the review articles and original scientific papers published earlier but considered basic for most of the methods currently used

Distribucija aktivnosti 90Sr i 137Cs u površinskim vodama i radioaktivnim oborinama duž hrvatske obale Jadranskog mora

The activities of 90Sr in the surface waters of the Adriatic Sea were investigated twice a year over the period 1963 – 1990 at four locations. A tendency was noted for the maximum concentrations to occur in the first half of the year. This can be explained by reflection of common spring activity peak on surrounding land masses. The 90Sr activity of the North Adriatic region was greater than the activities of south regions in both spring and autumn. The main residence time of 90Sr in the mixed sea-water layer was practically identical at all locations. The lower limit of 90Sr sedimentation rate in the Adriatic Sea was estimated to be 2.4 x 10-8 m s-1, the upper limit being 4.9 x 10-7 m s-1. The Chernobyl nuclear accident did not affect the activity of 90Sr in the Adriatic surface waters

210Pb and 226Ra in human urine

Opisan je način određivanja 210Pb i 226Ra u mokraći. Umjesto mokrog spaljivanja koncentrirani su 210Pb i 226Ra kao fosfati iz uzorka. Nakon toga se talože kao kromati. Priložen je niz eksperimentalnih podataka o normalnoj aktivnosti 210Pb i 226Ra u mokraći ispitanika.A method has been developed enabling the determination of 210Pb and 226Ra in urine samples based on an initial concentration as phosphates and a final precipitation as chromates. Results are given for normal values of 210Pb and 226Ra in human urine

Determinati0n of Sr90 in soil

Opisana je metoda za određivanje Sr90 u tlu. Dan je shematski prikaz metode i dobiveni rezultati na uzorcima sa područja S. R. Hrvatske.A method is described for the determination of Sr90 in soil. A scheme of the method and the results obtained on samples from different territories of S. R. Croatia are presented

226Ra u pitkoj vodi Hrvatske

Owing to its exceptional radiotoxicity 226Ra in drinking water may directly affect human health. Its presence was investigated in several categories of drinking water in Croatia: well water, tap water from several municipal water supply systems and bottled mineral water. The method of 226Ra determination was alpha-spectrometric measurement after radiochemical separation. The 226Ra content in all investigated categories of waters are below the legislative level permissible for human health.Zbog svoje izuzetne radiotoksičnosti, 226Ra u pitkoj vodi može izravno utjecati na ljudsko zdravlje. U radu je opisano istraživanje specifične aktivnosti 226Ra u pitkoj vodi Hrvatske, i to: u uzorcima bunarskih voda, uzorcima vodovodnih voda u nekoliko gradova Hrvatske i u mineralnim vodama. 226Ra je određen alfa-spektrometrijskim mjerenjem nakon radiokemijske separacije. Istraživanje je pokazalo da je količina 226Ra u svim ispitivanim kategorijama voda ispod razine koju zakonska regulative smatra tolerantnom po zdravlje čovjeka

The monitoring of fallout in Zagreb

Radioaktivno zagađenje prati se već 12 godina u okviru kontrole zagađenja okoliša na području Zagreba. Kontrola obuhvaća mjerenja beta i gama-aktivnosti. U radu su opisane primijenjene metode i dani rezultati.For the last 12 years the radioactive contamination of the rain has been monitored within a larger environmental survey. Beta and gamma activity control has been included. Data are presented on variations in radioactivity due to the time elapsed since the last nuclear explosion