Survey of planar chromatography and HPLC research in Croatia from 1980-1998

The article presents the fundamental and applied research in planar and high-performance liquid chromatography in Croatia from 1980 to 1998. Fields and subfields of the investigations, as well as the places where they were done, are shown separately. Also, papers of individual investigators are elaborated. On the basis of the data presented, conclusions about the quantity and quality of the papers are drawn

A non-targeted high-resolution mass spectrometry data analysis of dissolved organic matter in wastewater treatment

The dissolved organic matter (DOM) in wastewater is typically described by a limited number of concentration measurements of select DOM fractions or micro-contaminants, which determine the removal efficiency in a wastewater treatment. Current methods do not necessarily reflect the true performance of the treatment with regard to environmental and public health risk. Herein we describe the development and application of a non-targeted liquid chromatography-high resolution mass spectrometry (LC-HRMS) data analysis for the evaluation of wastewater treatment processes. Our data analysis approach was applied to a real wastewater system with secondary biological treatment and tertiary treatment consisting of sand filtration, UV-treatment, and chlorination. We identified significant changes in DOM during wastewater treatment. The secondary treatment removed 1617 of 2409 (67%) detected molecular features (grouped isotopologues belonging to the same molecule) from the influent while 255 of 1047 (24%) new molecular features appeared in the secondary effluent. A reduction in the number of large molecules (>450 Da) and an increase in unsaturated molecular features of the effluent organic matter was observed. Van Krevelen plots revealed the distribution of unsaturation and heteroatoms and Kendrick mass defect plots uncovered single bondCH2- homologous series implying a removal of heavy constituents in that fraction. The demonstrated approach is a step towards a more comprehensive monitoring of DOM in wastewater and contributes to the understanding of current treatment technologies

The Effect of Gum Arabic on the Nano / Microstructure and Optical Properties of Precipitated ZnO

The development of the nano/microstructure of ZnO particles precipitated from zinc acetylacetonate showed dependence on the presence of gum arabic. In the absence of gum arabic in near-neutral pH range ZnO rods, some of them hollow, precipitated, whereas in alkaline (NH4OH) medium the multipods (stars) were obtained. A strong effect of gum arabic was noticed both in the near-neutral pH range and in alkaline (NH4OH) medium. In both cases ZnO particles consisted of 1D subunits. The FT-IR spectra of ZnO particles precipitated in the presence of gum arabic showed the IR bands due to the residual content of this biopolymer. Gum arabic formed the corona on ZnO particles and played a key role in the precipitation process from nucleation to the final ZnO product. UV/Vis spectra were also recorded. The PL spectra of ZnO powders dispersed in pure ethanol were very similar. In the presence of ethanol characteristic peaks in the blue emission region were diminishing, thus softening the intrinsic defects responsible for this emission. It was assumed that this effect was due to the covering of oxygen vacancies (VO) at the interface ZnO/C2H5OH with the oxygen atoms present in ethanol. This work is licensed under a Creative Commons Attribution 4.0 International License

Bquant – Novel script for batch quantification of LCMS data

Quantitative target analysis by liquid chromatography coupled to mass spectrometry (LCMS) is ubiquitous in environmental, metabolomic and toxicological studies. Targeted LCMS methods are capable of the simultaneous determination of literally hundreds of analytes. Although acquiring of instrumental data is very fast, data post-processing i.e. quantification can be time consuming step (and)or dependent to various commercial software packages. In attempt to facilitate this drawback Wolfram Mathematica script for batch quantification of LCMS data was created. Script works with direct outputs of integration algorithms created by different instrument control software’s or custom created outputs. Key benefits of Bquant script are: • simple and automated routine for batch mode quantification • vast improvement in processing time (especially compared to manual interpretation) • data can be quickly re-analysed using different inputs Script was validated on various datasets and some of these were provided as working examples

Tolerantnost genotipova pšenice prema sulfonilurei u kulturi 'zigotnog' embriona

Tolerance of wheat genotypes to the sulfonylurea herbicide metsulfuron-methyl was studied using in vitro culture. Six randomly selected wheat genotypes were used for isolation. Mature embryos were inoculated onto a modified MS medium to which three concentrations of metsulfuron-methyl were added: I-30 g l-1, II-60 g l-1, and III-90 g l-1. The control group of embryos was cultivated on a herbicide-free medium. After one month of cultivation, callus fresh weight was measured. There were significant differences among the genotypes regarding their tolerance to metsulfuron-methyl. The Pobeda cultivar expressed the highest and the Lr-12 genotype had the lowest level of herbicide tolerance.Tolerantnost genotipova pšenice prema metsulfuron-metilu, herbicidu iz grupe sulfonilurea preparat a, ispitana je u in vitro kulturi zigotnog embriona. Za izolaciju korišćeno je šest genotipova pšenice. Embrioni su inokulisani na modifikovanu MS podlogu, kojoj je metsulfuron-metil dodat u tri koncentracije: I - 30 g l-1, II - 60 g l-1 i III - 90 g l-1. Kontrolna grupa embriona gajena je na podlozi bez herbicida. Posle mesec dana gajenja izmerena je sveža masa kalusa. Rezultat i su pokazali da je prisustvo metsulfuron-metila u podlozi izazvalo inhibiciju porasta kalusa kod svih genotipova. Međutim, genotipovi su se značajno razlikovali među sobom u pogledu reakcije na ovaj herbicid. Na najnižoj koncentraciji metsulfuron-metila (I - 30 g l-1), genotip Lr-12 imao je najvišu redukciju sveže mase kalusa, u odnosu na kontrolu (80.5 %), dok je najnižu redukciju imao genotip Vel (63.3 %). Više koncentracije herbicida imale su još jače inhibitorno dejstvo kod svih genotipova. Rezultat i su pokazali da je sorta Pobeda bila najtolerantnija, dok je genotip Lr-12 bio najosetljiviji na prisustvo metsulfuron-metila u podlozi

Uticaj proizvoda komposta na klijanje semena povrća

The aim of this work is determination of influence of different compost leachates and teas types on vegetables seed germination. Composts used for leachate and tea production were produced of municipal waste (MSW) and waste from tobacco industry (TW). Results achieved with MSW products were comparable to control. Compost products derived from TW showed significant phytotoxicity, which can be correlated with their chemical composition. Leachates from MSW compost lead to the lower germination index in comparison to MSW compost teas, which indicates the possibilites their application.Cilj ovog rada je određivanje uticaja različitih kompostnih čajeva i ekstrakata na klijanje semena povrća. Kompost korišćen za dobijanje ekstrakata i čajeva potiče od komunalnog otpada (MSW) i otpada iz duvanske industrije (TW). Rezultati postignuti sa komposnim produktima MSW su uporedivi sa kontrolom. Kompostni produkti dobijeni od TW pokazuju značajnu fitotoksičnost koja se može dovesti u vezu sa njihovim hemijskim sastavom. Ekstrakti od MSW komposta doveli su do nižeg germinacionog indeksa u poređenju sa čajevima, što ukazuje na mogućnosti njihove primene