Methodological aspects concerning sampling and determination of total selenium and selenium species in geothermal waters

Abstract

<jats:title>Abstract</jats:title><jats:p>The work presents the results of geothermal water sample analysis with respect to the determination of total selenium concentration. For this purpose, geothermal water (GT) samples were collected from three different intakes (GT-1, GT-2, GT-3) with similar temperatures of about 85°C. Tests were carried out to see if the methodology of sample preparation influenced total selenium concentration during analysis by inductively coupled plasma mass spectrometry (ICP-MS). Samples (raw and filtered) were preserved with nitric acid (HNO<jats:sub>3</jats:sub>) and mineralised in the laboratory. From the data obtained it was found that there is no significant difference between total selenium concentration in raw and filtered samples. Following mineralisation, the concentrations in the samples were below the limit of detection or limit of quantification. While different analytical steps or procedures are applied, the results of total selenium concentration can vary. Furthermore, high-performance liquid chromatography coupled with ICP-MS was used for the identification of selenium species. The results revealed that hexavalent selenium – Se(VI) – in the geothermal water was found only in samples collected from the GT-2 and GT-3 intakes.</jats:p>

Fluoride ions in groundwater of the Turkana County, Kenya, East Africa

“…For almost all samples charge balance error was acceptable (in range of ± 10%) except few ones (No. 4,12,15,and 27) possibly affected by the analytical methods used, physical parameters interfering with the measurements, and sampling method applied (Mika et al 2018;Wątor et al 2018Wątor et al , 2019Rusiniak et al 2020). Despite this, these samples were included in the statistical analysis and speciation modelling-a source of errors generated during sampling and laboratory instrumentation could not be verified based on the documentation and shortened chemical analysis reports gathered.…”

Label-Free Mass Spectrometry-Based Proteomic Analysis in Lamb Tissues after Fish Oil, Carnosic Acid, and Inorganic Selenium Supplementation

“…When thinking about speciation, one must consider the combination of an effective separation followed by well-designed detection. First, high-pressure liquid chromatography (HPLC) seems to be most suitable, especially when combined with ICP-MS (HPLC-ICP-MS) [ 15 , 29 , 30 ]. In the case of HPLC-ICP-MS, the compatibility of the retention times of respective standards with those of the compounds used is considered to be proof of its presence in a sample.…”

Inorganic Chromium Speciation in Geothermal Water of the Podhale Trough (Southern Poland) Used for Recreational Purposes

“…The thickness of the Paleogene series reaches 2.5-3.2 km, whereas that of the Mesozoic series exceeds 2.5 km. The depths of the boreholes actively exploiting geothermal water are in the range of 1 to 3.5 km [20,[36][37][38].…”