Mixing of endogenous CO and meteoric HO causes extremely efficient carbonate dissolution.

Karst corrosion of carbonate rocks by water with dissolved gases proceeds in most cases along two major scenarios: (i) meteoric water absorbs CO from soil and atmosphere, or (ii) ascending water of deep circulation carries with it dissolved endogenous gases, mainly CO and HS. We have observed a peculiar variant where meteoric water absorbs ascending endogenous gases at a natural gas vent on a travertine mound in Slovakia. Carbonate dissolution's extreme effectiveness is demonstrated by mineralization of rainwater ponded at a gas vent, rising to 3.

Isotope effects accompanying δ H, δ O and δ O analyses of aqueous saline solutions using cavity ring-down laser spectroscopy.

Rationale: The presence of substantial amounts of dissolved salts creates serious difficulties in isotope analyses of water samples using conventional isotope ratio mass spectrometry. Although nowadays laser-based instruments are increasingly used for this purpose, a comprehensive assessment of isotope effects associated with direct analyses of aqueous saline solutions using this technology is lacking.

Methods: Here we report the results of laboratory experiments aimed at quantifying isotope effects associated with direct, δ H, δ O and δ O analyses of single-salt solutions and double-salt mixtures prepared with a water of known isotopic composition.

Triple-isotope calibration of in-house water standards supplemented by determination of O content of USGS49-50 reference materials using cavity ring-down laser spectrometry.

The procedure of calibrating in-house water standards suitable for routine analyses of triple-isotope composition of water samples using Picarro L2140- CRDS analyser is presented and discussed. Such standards are indispensable for achieving and maintaining high quality of isotope analyses of water in terms of their precision and accuracy. A set of seven different water standards consisting of three in-house standards and four secondary standards commercially available was calibrated against VSMOW2/SLAP2 primary reference materials.

High-precision measurements of δH, δO and δO in water with the aid of cavity ring-down laser spectroscopy.

A thorough evaluation of measurement uncertainty together with control of short-term and long-term precision of measurements should be a basis of any successful quality assurance/quality control (QA/QC) strategy aimed at maintaining a high quality of the analytical process. Here we present the results of a comprehensive assessment of the analytical performance of a Picarro L2140-i CRDS laser spectrometer analysing δH, δO and δO in water. The assessment is based on results obtained during 15 months of continuous operation of this instrument (February 2017 to May 2018).

Natural radioactivity in groundwater--a review.

The issue of natural radioactivity in groundwater is reviewed, with emphasis on those radioisotopes which contribute in a significant way to the overall effective dose received by members of the public due to the intake of drinking water originating from groundwater systems. The term 'natural radioactivity' is used in this context to cover all radioactivity present in the environment, including man-made (anthropogenic) radioactivity. Comprehensive discussion of radiological aspects of the presence of natural radionuclides in groundwater, including an overview of current regulations dealing with radioactivity in drinking water, is provided.