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Comparison of Tandem Quadrupole Mass Spectrometry and Orbitrap High Resolution Mass Spectrometry for Analysis of Pharmaceutical Residues in Biota Samples

Abstract

This research demonstrates the development of reliable multi-component methods for the detection of antibiotic residues in environmental biota. The efficiency of analytical performance of ultra high performance liquid chromatography (UHPLC) techniques with triple quadrupole (QqQ-MS/MS) and Orbitrap high-resolution mass spectrometry (Orbitrap-HRMS) detectors is discussed. Antibiotic residues in biota samples collected in Latvia were analysed. The contamination status was determined as rather low within acceptable levels set by the European Union Regulations.

Open access
Floating Ceramics vs. Floating Oils: Search for Appropriate Conditions

Abstract

Ceramic granules fabricated from Quaternary clay at 1200°C were tested for their flotation ability in a water model system containing silicone oil. The presence of oil in the liquid phase improved flotation of granules, probably due to sorption of oil by ceramics. Coating of granules with SiO2 resulted in decreased flotation ability, irrespectively of the presence of oil. Granules were shown to be appropriate for bacterial colonization.

Open access
Mechanical Properties and Biocompatibility of a Biomaterial Based on Deproteinized Hydroxyapatite and Endodentine Cement

Abstract

Hydroxyapatite is used for bone reconstruction, in order to improve its mechanical properties different substances can be added. In our study new biomaterial is created from deproteinised hydroxyaptite and endodentic cement, its mechanical properties were tested. Material was implanted subcutaneous in rats, then histological and biocompatability tests were performed. Results indicate that stuff has good mechanical properties, short setting time and gradual resorption creating porosity and ability to integrate in bone.

Open access
Obtaining and Organophilisation of Smectite Clays with Reduced Iron Oxide Content

Abstract

Raw clays from the Baltic region are characterized as smectite containing clays with significant amount of naturally occurring impurities that limiting the potential applications of crude Baltic clay resources. Purification of clay samples from Šaltiškių deposit (Venta basin) was carried out by varied concentration hydrochloric acid solutions and resulted in fine removal of carbonates and iron oxide. The main idea of this work is to widen the possible applications of local clay resources providing a new type of raw material for further organoclay production.

Open access
Reversed-Phase High-Performance Liquid Chromatography Analysis of β-Lactoglobulin and α-Lactalbumin in Different Types of Milk

Abstract

The aim of this study was to detect major whey proteins α-lactalbumin and β-lactoglobulin by reversed-phase high-performance liquid chromatography (RP-HPLC). RPHPLC methods were developed using the column YMC Pack-C4, which enabled the separation of whey proteins within 30 min. Mobile phase was acetonitrile/water/0.1% trifluoroacetic acid (TFA) with gradient elution, flow rate was 1.0 mL·min−1, and the detection wavelength was 210 nm. Column temperature was 40°C and injection volume was 20 μL.

Milk samples contained α-lactalbumin and total β-lactoglobulin: No. 1 - 1500 mg·L−1 and 3600 mg·L−1; No. 2 - no α-lactalbumin and 450 mg·L−1 total β-lactoglobulin; No. 3 - 800 mg·L−1 and 94 mg·L−1, respectively.

Open access
Synthesis and Characterization of Cationic Poly(N-[3-Hexyldimethyl-Aminopropyl] Methacrylamide Bromide) Water-Soluble Polymer

Abstract

Water-soluble polymer, cationic poly(N-[3-hexyldimethyl-aminopropyl] methacrylamide bromide) (PHDAPMAA), is synthesized by radical polymerization and studied in terms of its solubility, viscosity, surface tension and conductivity. Viscometry and surface tension measurements confirmed that intramolecular hydrophobic microdomains were formed by the pendent alkyl chains. Conductivity of cationic polymer in aqueous solution was determined. Variation of conductivity versus concentration in investigated system exhibits a typical polyelectrolyte behaviour.

Open access
Chemical Element Accumulation in Peat and Its Humic Substances / Ķīmisko elementu akumulāciju kūdrā un tās humusvielās ietekmējošie faktori

Abstract

Peatland cores provide us with the potential to research aspects of atmospheric cycling of elements, such as metal pollutants, on timescales. Our study provides a better understanding of basic peat properties and their effects on trace and major element distributions in peat and its humic substances (HS). Humic substances isolated from an ombrotrophic bog peat profiles (Latvia) were used as study objects. Relations among peat depth, properties of peat and its HS (elemental composition), as well as element content, were studied.

Open access
Chemically and Thermally Activated Illite Clay from Latvia / Ķīmiski un termiski aktivēts Latvijas illīta māls.

Abstract

Materials were synthesized from illite based clay from Latvia by chemical and thermal activation using both NaOH and KOH solutions (4−6 M). Compressive strength and apparent porosity were measured. Effect of concentration of both solutions on the mechanical properties of the material was investigated by means of infrared spectroscopy (IR). Compressive strength data showed that alternative building materials could be obtained via alkaline activation.

Open access
Clay Ceramic Pellets for Water Treatment / Mālu keramikas granulas ūdens apstrādei

Abstract

Two different Quaternary clays from deposits Slucenieki and Prometejs were used for production of porous ceramic pellets. 3 wt % of sawdust additive was used to increase porosity of the obtained ceramic. Porosity and surface area of pellets was determined by mercury porosimetry. pH values after water immersion of fired pellets were determined using a pH meter. Pellets produced from both clays after sintering at similar temperatures had different pore size distribution and different sorption properties. Sorption properties were determined for a molecular substance (iodine) and anionic organic substance (methyl orange dye).

Open access