Methods for the determination of levoglucosan and other sugar anhydrides as biomass burning tracers in environmental samples – A review

Nowadays, there is a great pressure on finding an alternative source of energy. One such source is biomass combustion. Biomass is any organic matter such as wood, crops, seaweed, and animal wastes that during combustion emits energy but also smoke and solid residue. Biomass burning tracers, such as levoglucosan, mannosan and galactosan, are sugar anhydrides produced during burning of biomass that contain cellulose and hemicellulose. Analysis of environmental samples for tracers is the source of information about the type of biofuel burned. In this article, a literature review of the preparation and determination of biomass burning tracers for environmental samples was presented. The review discusses the preparation of different samples (particulate matter, soils, sediments, biological samples), extraction, derivatization, and determination. Amongst determination methods the most popular was gas chromatography with mass spectrometry but other techniques were also used, such as high‐performance liquid chromatography with aerosol charge detection, capillary electrophoresis with pulsed amperometric detection, and ion chromatography with pulsed amperometric detection.     

Application of liquid separation techniques to the determination of the main urinary nicotine metabolites

A rapid procedure for the analysis of the main nicotine metabolites (cotinine, trans-3′-hydroxycotinine) in urine has been worked out. The procedure includes isolation of nicotine and its metabolites from urine by means solid–liquid extraction technique using resin Amberlite XAD-2 and then quantitation by the use of thin-layer chromatography with densitometry (in reflection mode). GC–MS was applied to confirm the results obtained by TLC. The procedure was applied to the analysis of cotinine concentrations in urine samples taken from children living in Upper Silesia region (Poland). Among 444 investigated children we did not find cotinine almost in 60% but in 15% of this population, there were children who could have been exposed to cigarette smoke.     

Determination of 7-Ketocholesterol and 7-Hydroxycholesterol in Meat Samples by TLC with Densitometric Detection

JPC – Journal of Planar Chromatography – Modern TLC - Concentrations of two oxycholesterols: 7-ketocholesterol and 7- hydroxycholesterol in meat samples (raw and cooked) were determined...     

Scalable and Recyclable All‐Organic Colloidal Cascade Catalysts

We report on the synthesis of core–shell microparticles (CSMs) with an acid catalyst in the core and a base catalyst in the shell by surfactant‐free emulsion polymerization (SFEP). The organocatalytic monomers were separately copolymerized in three synthetic steps allowing the spatial separation of incompatible acid and base catalysts within the CSMs. Importantly, a protected and thermo‐decomposable sulfonate monomer was used as acid source to circumvent the neutralization of the base catalyst during shell formation, which was key to obtain stable, catalytically active CSMs. The catalysts showed excellent performance in an established one‐pot model cascade reaction in various solvents (including water), which involved an acid‐catalyzed deacetalization followed by a base‐catalyzed Knoevenagel condensation. The CSMs are easily recycled, modified, and their synthesis is scalable, making them promising candidates for organocatalytic applications.     

Densitometric TLC Analysis of Azaarenes in Grilled Meat

JPC – Journal of Planar Chromatography – Modern TLC - A TLC method with densitometric detection is described for qualitative and quantitative analysis of seven azaarenes —...     

Concentration of chosen oxycholesterols in plasma of pregnant women with pregnancy-induced hypertension

Solid-phase extraction (SPE) was applied for isolation of oxycholesterols from plasma lipid extract from pregnant women with hypertension and from a control group. Separation of oxycholesterols fraction was performed in an SD II horizontal chamber (Chromdes, Poland) using silica gel and octadecyl RPC18 silica gel TLC plates (Merck and Machery Nagel). Visualization was carried out under UV light after Liebermann-Burchard reaction specific for cholesterol and its derivatives. The oxycholesterols (5-cholestene-3beta-ol-7-one, sum of 5-cholestene-3beta, 7beta-diol and 5-cholestene-3beta, 7alpha-diol and sum of 5alpha,6alpha-epoxycholestan-3beta-ol and 5beta, 6beta-epoxycholestan-3beta-ol) were quantified by chromatograms scanning in reflectance and fluorescence mode using a CS 9301 densitometer (Shimadzu). The total concentration of the investigated oxycholesterols in the plasma of pregnant women was up to 5000 ng/mL and was statistically significantly higher in women with pregnancy induced hypertension (PIH).