Identification and characterization of asphaltenes, the most polar and predominantly aromatic components of crude oil, still post a challenge for researchers in the oil industry, owing to their complex molecular architecture. Recently, much effort has been devoted to understanding their structure and physicochemical properties. In this paper, a combination of diffusion-ordered NMR spectroscopy (DOSY) and statistical multiway methods was used to investigate petroleum samples and asphaltenes of different origin. Such multiway TUCKER3 decomposition has been used for the first time to analyze the two-dimensional matrix of complex nuclear magnetic resonance (NMR) data for petroleum samples. DOSY NMR spectra of 50 samples (45 for establishing the statistical model and 5 for its validation) were recorded and evaluated by an in-house-developed code incorporating multiway analysis to set up a tool for predicting their identity and origin. A statistical model was developed that can identify and separate asphaltene ...

The development of a quantitative in-line Raman spectroscopic method for the monitoring of the active pharmaceutical ingredient, omeprazole synthesis reaction, and characterization of the reaction components is described. In-line monitoring was performed both with Fourier transform and dispersive Raman spectrometers. Prior to reaction monitoring, the reaction components were characterized off-line by means of Raman and NMR spectroscopy, both in solution and in solid state. To unequivocally confirm the presence of each component in the reaction mixture, a state of the art LC-SPE/NMR methodology was also used. Owing to its higher sensitivity, dispersive Raman spectroscopy was further employed for quantification purposes. The spectroscopic measurements and the complementary HPLC analyses, used in the calibration development, were gathered from a set of experiments, performed at a 1 L scale. On the basis of the data set obtained from the calibration experiments, a predictive partial least-squares (PLS) regres...

Nonconventional fuels are gaining in importance due to limited availability of crude oil and rapid growth of the automotive industry and transportation sector which is resulting in increased emissions into the environment. Exhaust gases associated with combustion of fossil fuels used in transportation sector reduce air quality and thus have direct impact on human health. Biofuels are more environmentally friendly alternative fuels that are produced from animal or vegetable feedstocks. Developments of new and more effective analytical methods are increasing since the knowledge of the chemical composition represents challenge to analysts. In this paper, the most common and important chromatographic and spectroscopic methods in the analysis of feedstocks and nonconventional fuels are shown. The paper also presents the characteristic chromatogram and spectra of certain feedstocks for biofuel production and chromatogram of biodiesel recorded in the Laboratory for testing, water, hydrocarbons and materials (Central Testing Laboratory Department) in INA Petroleum Industry.

U svijetu danasnjice svima je poprilicno jasno da mediji igraju veliku ulogu u nasim životima. Oni su u velikoj mjeri i razlog „modernih glavobo

Synthesis of the dioxidomolybdenum(VI) complexes [MoO2(HLR)(MeOH)]Cl (1–3) was carried out by using MoO2Cl2 and the corresponding ONO aroylhydrazone ligand H2LR (ligand H2LR is salicylaldehyde isonicotinoylhydrazone (H2LSIH), 2-hydroxy-naphthaldehyde isonicotinoylhydrazone (H2LNIH), or p-(N,N′-diethylamino)salicylaldehyde isonicotinoylhydrazone (H2LEt2NSIH) in methanol. Compounds [MoO2(HLR)(H2O)]Cl (1a–3a) were obtained upon exposure of the corresponding mononuclear complexes 1–3 to moisture. Deprotonation of the mononuclear complexes 1–3 was performed by using Et3N as a base (by the conventional solution based-method and by the mechanochemical approach) as well as by UV-light assisted reactions yielding [MoO2(LSIH)(MeOH)] (4), [MoO2(LNIH)(MeOH)] (5) and [MoO2(LEt2NSIH)]n (6), respectively. Crystal and molecular structures of all complexes were determined by the single crystal X-ray diffraction method. The complexes were further characterized by elemental analysis, IR spectroscopy, TG analysis, one- and two-dimensional NMR spectroscopy and powder X-ray diffraction.

NMR spectroscopy in combination with statistical methods was used to study vacuum residues and vacuum gas oils from 32 crude oils of different origin. Two chemometric metodes were applied. First- ly, principal component analysis on complete spectra was used to perform classification of samples and clear distinction between vacuum residues and vacuum light and heavy gas oils were obtained. To quanti- tatively predict the composition of asphaltenes, principal component regression models using areas of res- onance signals spaned by 11 frequency bins of the 1 H NMR spectra were build. The first 5 principal com- ponents accounted for more than 94 % of variations in the input data set and coefficient of determination for correlation between measured and predicted values was R 2 = 0.7421. Although this value is not signifi- cant, it shows the underlying linear dependence in the data. Pseudo two-dimensional DOSY NMR exper- iments were used to assess the composition and structural properties of asphaltenes in a selected crude oil and its vacuum residue on the basis of their different hydrodynamic behavior and translational diffusion coefficients. DOSY spectra showed the presence of several asphaltene aggregates differing in size and interactions they formed. The obtained results have shown that NMR techniques in combina- tion with chemometrics are very useful to analyze vacuum residues and vacuum gas oils. Furthermore, we expect that our ongoing investigation of asphaltenes from crude oils of different origin will elucidate in more details composition, structure and properties of these complex molecular systems.

U ovome preglednom radu opisane su najznacajnije i najcesce koristene jedno i dvodimenzijske tehnike NMR u analizi biodizela. Biodizel je ekoloski prihvatljivo alternativno gorivo koje se sastoji od zasicenih i nezasicenih metilnih estera masnih kiselina. Buduci da analiza kemijskog sastava i proucavanje svojstava biodizela i ostalih biogoriva analiticarima predstavlja izazov, sve vise se razvijaju nove i ucinkovitije analiticke metode. Spektroskopija NMR jedna je od takvih metoda koja može dati niz informacija o sastavu i strukturi biodizela. Nadalje, analiza spektara NMR pruža vrijedne podatke i o sirovinama iz kojih nastaje biodizel te o procesu esterifikacije. Isto tako primjenom tehnika 1H i 13C NMR može se odrediti sastav aditiva koji se dodaju za sprecavanje rasta mikroorganizama i sastav smjese acetilglicerola i slicnih nusproizvoda sinteze biodizela. U tu svrhu se osim spektara 1H i 13C analiziraju i spektri 31P. U radu su dani karakteristicni spektri biodizela, dizela, biljnog ulja tretiranog vodikom te reprezentativan spektar jednog od uzoraka biocida snimljeni u Laboratoriju za spektroskopiju NMR u INA d.d.

Crna Gora ima veliko majhnih vodotokov, od katerih vecina ni energetsko izkoriscena. Med njimi je tudi reka Bjelojevicka, ki ima dober potencial za gradnjo ene ali vec majhnih hidroelektrarn, kar ima energetski pomen za Crno Goro, kot državo s slabo razvito politiko pridobivanja energije iz obnovljivih in ekolosko sprejemljivih virov energije. V magistrskem delu je raziskana možnost izkoriscanja hidropotenciala reke Bjelojevicke, s poudarkom na ovire, ki se pojavljajo v tem procesu.