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The curative waters of HCO₃-SO₄-Mg-Na+H₂S chemical type and 0.6-0.8 g/dm³ total dissolved solids are exploited in Horyniec Spa located at the northern boundary of the Carpathian Foredeep, near the Polish-Ukrainian border. Although these waters occur at relatively shallow depths (their aquifer is encountered about 30 m below the ground surface), they are quite well protected from surface pollutants by a cover of clayey sands. This paper revises and discusses the origin of specific chemical components of these waters based on the following analyses of stable isotopes: (a) δ³⁴S in SO₄²⁻, H₂S, and CaSO₄·2H₂O, (b) δ¹⁸O in SO₄²⁻, H₂O, and CaSO₄·2H₂O, and (c) δ²H in H₂O and CaSO₄·2H₂O. The most important process which takes place in the aquifer is the dissolution of gypsum present in the Miocene formation and subsequent bacterial reduction of sulphate ion to hydrogen sulphide in the presence of an organic matter. This process shifts both δ³⁴S and δ1¹⁸O of sulfate ions towards higher concentration of heavy isotopes by several per mil in comparison to that in the original Miocene gypsum. The hydrogen sulphide generated this way (up to a concentration of 45 mg/dm³) is highly depleted in a heavy isotope by about 41‰ with respect to a sulphate ion.

A new semi-empirical formula was devised for liquid-vapour fractionation at thermodynamic equilibrium, which is valid for the whole temperature range, i.e. from the freezing to the critical temperature, Tc. The new formula contains three parameters (A, B and C) only: [image omitted] where X is the ratio of saturated vapour pressure at temperature T to the critical pressure. Physical reasons for the above formula are presented. The following numerical values of the parameters have been obtained by fitting the above expression to the experimental data from literature: A=1.3781×106, B=1.8876×103, C=3655.8 for 18O/16O, and A=18.993×106, B=40.798×103, C=18405 for D/H isotope fractionation. In both cases, X was calculated from the Van der Waals semi-empirical formula for vapour pressure, which has only one crude parameter: [image omitted] [ABSTRACT FROM AUTHOR]

Refinements have been made to achieve over 99% yield in the conversion of CO to CO2 in order to improve the reproducibility and accuracy of δ18 O measurements in sulfates. BaSO4 (10-15 mg) was mixed with an identical amount of spectrographic-grade graphite and loaded into a Pt boat. The mixture was gradually heated to 1100 °C to reduce sulfate to CO and CO2; the former gas was simultaneously converted to CO2 by a glow discharge between Pt electrodes immersed in a magnetic field (produced by a pair of external neodymium magnets). A small memory effect was noticed during the analysis (less than 0.3‰ per 10‰ difference in δ18 O between two subsequently analysed samples). The memory effect, however, was suppressed by repetitive preparation of the same specimen. CO2 produced in this way from sulfate reference samples was analysed on a dual inlet and triple collector mass spectrometer along with CO2 equilibrated with VSMOW, GISP and SLAP water reference samples. To avoid large departures of measured isotope ratios from 18O/16O of the working calibrator we used CO2 gas prepared from ocean water sulfate for this purpose. The calibrated δ18 O values (in ‰) obtained in this way for NBS-127, IAEA SO-5 and IAEA SO-6 reference materials were 8.73 ± 0.05, 12.20 ± 0.07 and -10.43 ± 0.12, respectively. [ABSTRACT FROM AUTHOR]

Presents a study which discussed the use of Cu2O - NaPO3 mixtures for sulfur dioxide extraction from BaSO4 for sulfur isotope analysis. Method to extract sulfur dioxide from sulfates; Assessment of the amount of extracted sulfur dioxide and reaction time; Information on the plots of sulfur dioxide yield as a function of reaction time.