Evaluation of MIP-OES as a detector in DLLME procedures: application to Cd determination in water samples

High-power microwave induced plasma optical emission spectrometry (MIP-OES) constitutes a serious alternative to inductively coupled plasma optical emission spectrometry (ICP-OES) for elemental analysis. To improve the analytical capabilities of MIP-OES, dispersive liquid–liquid microextraction (DLLME) procedures seems to be, a priori, a very promising choice for trace and ultra-trace analysis in complex matrices. Nevertheless, to date, DLLME has never been coupled to MIP-OES. The goal of the present work is to investigate the capability of MIP-OES as a detector in DLLME procedures. To this end, spectral and non-spectral interferences caused by the presence of common DLLME extractants (i.e., chloroform and supramolecular solvent based on 1-decanol and THF) in MIP-OES have been evaluated. Results reveal the occurrence of both spectral and non-spectral interferences due to carbon-based molecular bands emission in MIP-OES. Carbon-based molecular emission (i.e. C2 and CH) significantly affects analyte wavelengths above 328 nm. By the appropriate selection of experimental conditions (i.e. analyte wavelength and nebulizer gas flow rate), both spectral and non-spectral interferences could be mitigated allowing elemental analysis by means of DLLME-MIP-OES. Different DLLME methodologies have been developed for Cd determination in water samples (i.e., tap, sparkling and synthetic seawater) by MIP-OES. These methodologies afford an enrichment factor of 46 and 42 for chloroform and supramolecular-based solvent DLLME procedures, respectively, and a limit of detection (LoD) of 1 μg L−1. This LoD is 100-fold lower than that obtained by conventional MIP-OES (i.e. no DLLME) due to both analyte preconcentration and the beneficial effect of organics on aerosol generation and transport. These analytical figures of merit are equivalent to those previously reported for DLLME-ICP-OES and allows Cd determination in water samples according to current international policies.The authors would like to thank the Generalitat Valenciana (CONSELLERIAAGRICULTURA4-17T) and the University of Alicante (VIGROB-050; UADIF17-42; UAUSTI16-02) for the financial support of this work

Cryoconite – from minerals and organic matter to bioengineeredsediments on glacier's surfaces

Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite.Moreover, amajor driver of cryoconite colouringwas the concentration of organicmatter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceaewere themost common. Themost of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb andHg in cryoconite collected fromEuropean glaciers near industrialized regions, corroborating cryoconite as element-specific collector and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may bemore than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystem

Geochemistry and mineralogy of technogenic soils developed on old mine heaps of abandoned iron ore mines in the Ławęczna area (Holy Cross Mountains, south-central Poland)

The article presents the results of preliminary geochemical and mineralogical studies of technogenic soils (Technosols) of abandoned iron ore mines on the Ławęczna Hill near Miedziana Góra in the Holy Cross (Świętokrzyskie) Mountains, southcentral Poland. The results of chemical analyses (XRF) were used to calculate the soil enrichment factors of arsenic, copper, iron, lead and zinc, and compare the element concentrations to their levels in uncontaminated soils across Poland and in the city of Kielce. The highest values of soil enrichment factors of metals (As 27.699, Ni 26.455, Cu 9.353, Zn 3.344, Pb 0.62) were recorded for the sand fraction composed of iron oxyhydroxides and hematite, whereas the lowest (Ni 0.22, Cu 0.069, Zn 0.007, Pb 0.028) for the clay–silt and sand fractions, which were primarily composed of calcite and quartz as well as for gravel fraction. The clay-silt fraction shows the highest enrichment in arsenic (27.69). The examined metals and arsenic show positive geochemical anomalies

The influence of urban agglomeration on a small natural water reservoir

The aim of the study was to determine the influence of urban agglomeration on a small, natural water reservoir which, as a result of the expansion of the city of Poznań, has become an urban lake. In the vegetation period 2015, the chemistry of its water was studied, and in September additional samples of bottom sediments, plants and fish were collected for analysis in order to determine the content of heavy metals. In terms of productivity, no significant influence of the catchment was recorded. In the 1980s the lake was defined as eutrophic, and in 1996 as α-mesotrophic and such a state continues until today. This is the result of protective activity undertaken by its new owner. The adverse influence of the urbanization of the surrounding areas was reflected by the increased content of lead in particular elements of this ecosystem, that is, in bottom sediments, plants and fish muscles

Speciation analysis of arsenic, antimony and selenium in Lednica lake water

The paper describes the results of determination of different forms arsenic, antimony and selenium present in lakes water (As, Sb (III), As, Sb (V), Se (IV) and their organic forms). The studies of speciation analysis of ultratraces metal concentrations determined by hydride generation atomic absorption spectrometry give the imagination of processes are proceeding in water environment