• MeSH
• Chemistry Techniques, Analytical MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• chemie, klinická chemie

This review presents a recent developments and appli-cations of the slurry sampling (SS) as an approach for the minimization of sample preparation prior to the analysis of solid samples by atomic spectrometry. The paper is fo-cused on the description of the basic critic factors of SS. Some advantages or drawbacks of this technique are also discussed. At the end, the applications of combined SS and atomic spectrometry for the determination of metals in various solid matrices (environmental, biological, food and others) are presented.

• MeSH
• Food Analysis MeSH
• Food Inspection MeSH
• Animal Feed microbiology   standards   MeSH
• Microbiological Techniques standards   MeSH
• Food Microbiology MeSH
• Food standards   MeSH
• Food Chain MeSH
• Publication type
• Guideline MeSH

• Conspectus
• Metrologie. Standardizace
• NML Fields
• mikrobiologie, lékařská mikrobiologie
• zemědělství a potravinářství
• NML Publication type
• brožury

Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L(-1) TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants.

• MeSH
• Calibration MeSH
• Excipients chemistry   MeSH
• Mercury analysis   MeSH
• Spectrophotometry, Atomic methods   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

A method employing the direct immersion solid-phase microextraction followed by GC-MS analysis is presented for the determination of essential oils components in herbal tea infusions, i.e. their direct content in the liquid phase. The extraction performances were compared using five different microextraction fibres. Significant parameters affecting sorption process such as sample amount, sorption and desorption time and temperature, stirring speed, pH adjustment and effect of ionic strength were optimised and discussed. By optimising the key parameters, a detection limits (LOD = S/N × 3) for ten target marker compounds were obtained in the range from 5.3 to 48.2 ng/mL with recoveries ranged between 93.03 and 100.50%. Intra-day and inter-day repeatability at three concentration levels were found to be 1.1-15.3 and 7.2-15.5% RSD, respectively. Finally, the optimised procedure enabling a rapid and simple analysis of essential oils was applied for the direct determination of these compounds in ten herbal tea infusions.

• MeSH
• Solid Phase Microextraction methods   MeSH
• Beverages analysis   MeSH
• Oils, Volatile analysis   isolation & purification   MeSH
• Gas Chromatography-Mass Spectrometry MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH

The presented study investigates the use of passive sampling, i.e. solid phase microextraction with polydimethylsiloxane fibers (PDMS-SPME), to assess the bioavailability of fiver neutral organic chemicals (phenanthrene, pyrene, lindane, p,p'-DDT, and PCB 153) spiked to natural and artificial soils after different aging times. Contaminant bioavailability was assessed by comparing PDMS concentrations with results from a 10 day bioaccumulation test with earthworms (Eisenia fetida). The hypotheses tested were (i) organic carbon (OC) normalization, which is commonly used to account for sorption and bioavailability of hydrophobic organic chemicals in soil risk assessment, has limitations due to differences in sorptive properties of OC and aging processes (i.e. sequestration and biodegradation) and (ii) PDMS-SPME provides a more reliable measure of soil contaminant bioavailability than OC normalized soil concentrations. The above stated hypotheses were confirmed since the results showed that: (i) the PDMS/soil organic carbon partition ratio (R) accounting for the role that OC plays in partitioning significantly differed between soils and aging times and (ii) the correlation with earthworm concentrations was better using porewater concentrations derived from PDMS concentrations than when organic normalized soil concentrations were used. Capsule: Sorption of organic compounds measured by SPME method and their bioavailability to earthworms cannot be reliably predicted using OC content.

• MeSH
• Soil Pollutants chemistry   metabolism   MeSH
• Solid Phase Microextraction * MeSH
• Environmental Monitoring MeSH
• Oligochaeta chemistry   metabolism   MeSH
• Organic Chemicals analysis   metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Research Support as Topic MeSH
• Calibration MeSH
• Polycyclic Compounds analysis   MeSH
• Polymers analysis   chemistry   MeSH
• Reproducibility of Results MeSH
• In Vitro Techniques MeSH
• Air MeSH

Head-space solid phase microextration (SPME), followed by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOFMS), has been implemented for the analysis of honey volatiles, with emphasis on the optimal selection of SPME fibre and the first- and second-dimension GC capillaries. From seven SPME fibres investigated, a divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) 50/30 microm fibre provided the best sorption capacity and the broadest range of volatiles extracted from the headspace of a mixed honey sample. A combination of DB-5ms x SUPELCOWAX 10 columns enabled the best resolution of sample components compared to the other two tested column configurations. Employing this powerful analytical strategy led to the identification of 164 volatile compounds present in a honey mixture during a 19-min GC run. Combination of this simple and inexpensive SPME-based sampling/concentration technique with the advanced separation/identification approach represented by GCxGC-TOFMS allows a rapid and comprehensive examination of the honey volatiles profile. In this way, the laboratory sample throughput can be increased significantly and, at the same time, the risk of erroneous identification, which cannot be avoided in one-dimensional GC separation, is minimised.

• MeSH
• Time Factors MeSH
• Honey analysis   MeSH
• Solid Phase Microextraction methods   MeSH
• Gas Chromatography-Mass Spectrometry methods   MeSH
• Temperature MeSH
• Volatilization MeSH
• Publication type
• Comparative Study MeSH

An investigation was carried out on the effect of inoculation methods on the compost of an organic fraction of municipal solid waste. Three types of white-rot fungi (Phanerochaete chrysosporium, Trametes versicolor and Fomes fomentarius), and a consortium of these fungi, were used. The study assessed their influence on microbial enzymatic activities and the quality of the finished compost. It was found that the addition of white-rot fungi to municipal solid waste (after 37days of composting) could be a useful strategy for enhancing the properties of the final compost product. In comparison with the control sample (compost without inoculation), it accelerates degradation of solid waste as indicated by changes in C/N, electrical conductivity and pH. However, the effectiveness of waste degradation and compost maturation depends on the type of microorganism used for inoculation. The presence of inoculants, such as Trametes versicolor and Fomes fomentarius, led to a higher degrading ratio and a better degree of maturity. This resulted in an increase of enzymatic activities (especially dehydrogenase and protease) and a germination index in comparison with inoculation using Phanerochaete chrysosporium or a consortium of fungi.

• MeSH
• Biodegradation, Environmental MeSH
• Coriolaceae metabolism   MeSH
• Nitrogen metabolism   MeSH
• Enzymes metabolism   MeSH
• Fungi metabolism   MeSH
• Hydrogen-Ion Concentration MeSH
• Refuse Disposal methods   MeSH
• Phanerochaete metabolism   MeSH
• Soil * MeSH
• Soil Microbiology * MeSH
• Trametes metabolism   MeSH
• Solid Waste * MeSH
• Carbon metabolism   MeSH
• Publication type
• Journal Article MeSH

Extrakce na pevnou fázi je rychlý, jednoduchý, účinný a flexibilní způsob přípravy vzorků k vlastníanalýze, využitelný v mnoha oblastech analýzy (farmacie, biochemie, potravinářství, životní prostředí aj.). Výhodná je možnost použití v on-line systémech a v automatických systémech. Velmiširoká ikála nabízených typů sorbentů a využití jejich kombinace tak z extrakce na pevnou fázivytváří účinný způsob k izolaci a prekoncentraci analytu ze složité matrice vzorku.

Extraction on the solid phase is a rapid, simple, effective, and flexible method of preparation ofsamples for the analysis proper and it can be used in many areas of analysis (pharmacy, biochemistry, food industry, environmental examination, etc.). Possible use in on-line and automatic systemsis also advantageous. A very wide scale of proposed sorbents and the use of their combinations thusmake extraction on the solid phase an effective method for the isolation and preconcentration of theanalyte from the complex matrix of the sample.

• MeSH
• Chemistry Techniques, Analytical methods   MeSH
• Ion Exchange Resins MeSH
• Polymers chemistry   MeSH
• Solvents chemistry   MeSH
• Silicone Gels chemistry   MeSH