All-in-one 2LabsToGo system for analysis of ergot alkaloids in whole rye.

Ergot alkaloids, naturally occurring mycotoxins of Claviceps fungi, pose health risks. This necessitates accurate analysis methods to ensure food safety. This study explored the open-source miniaturized all-in-one 2LabsToGo system to analyze ergot alkaloids in whole rye samples.

Miniaturized open-source 2LabsToGo screening of lactose-free dairy products and saccharide-containing foods.

The open-source 2LabsToGo system is the only one in its nature. It combines in one miniaturized instrument all relevant steps normally performed in a chemical and biological laboratory. For the first time, the applicability of the 2LabsToGo system was studied for screening 17 food products.

2LabsToGo─Recipe for Building Your Own Chromatography Equipment Including Biological Assay and Effect Detection.

A complete recipe for building your own chromatography equipment from readily available materials is introduced. It combines sample separation (chemistry laboratory) with biological effect detection (biology laboratory). This hyphenation of two disciplines is necessary for prioritizing important compounds in complex samples.

Open-source all-in-one LabToGo Office Chromatography.

Print and media technologies were used uncommonly in the field of chromatography and explored in application to create a miniaturized all-in-one LabToGo system. This novel research field termed Office Chromatography (OC) uses additive manufacturing in terms of 3D printing of operational parts as well as open-source hard- and software. The OCLab2 presented here has been considerably extended in its functionalities.

On-surface autosampling for liquid chromatography-mass spectrometry.

An on-surface multi-purpose autosampler was built for liquid chromatography-mass spectrometry (LC-MS) based on the autoTLC-MS interface, taking advantage of open-source hard- and software developments as well as 3D printing. Termed autoTLC-LC-MS system, it is introduced for orthogonal hyphenation of normal phase high-performance thin-layer chromatography with reversed phase high-performance LC (HPLC) and high-resolution MS (HRMS). For verification of its functionality, a multi-class antibiotic mixture was applied as a calibration band pattern on an adsorbent layer and detected by the Bacillus subtilis bioassay.

Determination of mono- and diacylglycerols from E 471 food emulsifiers in aerosol whipping cream by high-performance thin-layer chromatography-fluorescence detection.

Mono- and diacylglycerol (MAG and DAG) emulsifiers (E 471) are widely applied to regulate techno-functional properties in different food categories, for example, in dairy products. A method for the determination of MAG and DAG in aerosol whipping cream by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD) after derivatization with primuline was developed. For sample preparation, aerosol whipping cream was mixed with ethanol, followed by the addition of water and liquid-liquid extraction with tert-butyl methyl ether.

Characterization of E 472 food emulsifiers - determination of bound and free fruit acids, free glycerol and ash content.

Emulsifiers of the type E 472 are esters of fruit acids and mono- and diacylglycerols (MAG and DAG), which are used to adjust techno-functional properties in various food products. The most dominant representatives of E 472 emulsifiers are acetic acid esters (E 472a), lactic acid esters (E 472b), citric acid esters (E 472c), and mono- and diacetyl tartaric acid esters (E 472e). For the determination of fruit acids, a high-performance liquid chromatography method with ultraviolet light (HPLC-UV) detection was developed.

Characterization of E 472 food emulsifiers by high-performance thin-layer chromatography with fluorescence detection and mass spectrometry.

Esters of fruit acids including acetic acid and mono- and diacylglycerols (MAG and DAG), also known as E 472 emulsifiers, are used in the food industry as food additives to adjust techno-functional properties like viscosity, emulsion stability and foaming stability in various products, mainly dairy products. Based on the respective acids, E 472 emulsifiers are classified in several categories with acetic acid esters (ACETEM, E 472a), lactic acid esters (LACTEM, E 472b), citric acid esters (CITREM, E 472c), and mono- and diacetyl tartaric acid esters (DATEM, E 472e) as the most prominent representatives. Besides fruit acid esters, E 472 emulsifiers mainly comprise MAG, DAG, triacylglycerols, free fatty acids, free fruit acids and free glycerol in different amounts.

Characterization of E 471 food emulsifiers by high-performance thin-layer chromatography-fluorescence detection.

Mono- and diacylglycerol (MAG and DAG) emulsifiers, also known as food additive E 471, are widely used to adjust techno-functional properties in various foods. Besides MAGs and DAGs, E 471 emulsifiers additionally comprise different amounts of triacylglycerols (TAGs) and free fatty acids (FFAs). MAGs, DAGs, TAGs and FFAs are generally determined by high-performance liquid chromatography (HPLC) or gas chromatography (GC) coupled to mass selective detection, analyzing the individual representatives of the lipid classes.

Photooxidation of Octahydro Tetramethyl Naphthalenylethanone in Perfumes and Aftershaves.

For consumer safety reasons, cosmetics that are exposed to light are evaluated with respect to phototoxicity and/or photoallergy (photosensitization). For perfumes/aftershaves, however, these tests are not performed with the cosmetic product but only with single fragrance compounds, which may influence the outcome. In the presence of a sensitizer, photoinduced oxidation of unsaturated fragrances might result in the formation of unwanted products.

Analysis of unauthorized Sudan dyes in food by high-performance thin-layer chromatography.

Food authenticity and food safety are of high importance to organizations as well as to the food industry to ensure an accurate labeling of food products. Respective analytical methods should provide a fast screening and a reliable cost-efficient quantitation. HPTLC was pointed out as key analytical technique in this field.

Determination of caffeine, theobromine and theophylline in Mate beer and Mate soft drinks by high-performance thin-layer chromatography.

Mate beer and Mate soft drinks are beverages produced from the dried leaves of Ilex paraguariensis (Yerba Mate). In Yerba Mate, the xanthine derivatives caffeine, theobromine and theophylline, also known as methylxanthines, are important active components. The presented method for the determination of caffeine, theobromine and theophylline in Mate beer and Mate soft drinks by high-performance thin-layer chromatography with ultraviolet detection (HPTLC-UV) offers a fully automated and sensitive determination of the three methylxanthines.

Detection of estrogen active compounds in hops by planar yeast estrogen screen.

Hops used in the brewing process of beer for flavoring are known to contain estrogen active compounds (EAC) and to be the source of EAC in beer. The recently developed planar yeast estrogen screen (pYES) with the substrate resorufin-β-d-galactopyranoside (RGP) successfully was applied for the detection of EAC in ethanolic extracts of hops pellet samples. The only pYES positive compound was identified as the hop flavanone prenylnaringenin (PN) by thin-layer chromatography-mass spectrometry.

Selective two-dimensional effect-directed analysis with thin-layer chromatography.

There are thousands of organic trace substances in the environment that are not fully characterized, and evaluation of their relevance to the ecosystem is difficult. Effect-directed analysis (EDA) is a suitable tool to assess the effects of a substance via in-vitro bioassays, which can provide information about the relevance of the substance. High-performance thin-layer chromatography (HPTLC) has been shown to be a good method for fractionation.

Logit-log evaluation of planar yeast estrogen screens.

Receptor assays like the yeast estrogen screen (YES) performed in microtiter plates normally provide dose-response curves with a sigmoidal shape in semi-log plots. Such sigmoidal plots can be linearized by the logit function resulting in logit-log plots, as mainly known for the evaluation of enzyme-linked immunosorbent assays and radioimmunoassays. Since the planar yeast estrogen screen (pYES) represents the transfer of the receptor assay YES to high-performance thin-layer chromatography (HPTLC), it was assumed to obtain sigmoidal shaped dose-response curves from the measured signals, which subsequently could be used to generate logit-log plots.

Planar yeast estrogen screen with resorufin-β-d-galactopyranoside as substrate.

For the planar yeast estrogen screen (pYES), 4-methylumbelliferyl-β-d-galactopyranoside was generally employed as substrate, delivering blue fluorescing 4-methylumbelliferone after enzymatic cleavage by the YES reporter β-d-galactosidase as the positive signal for the presence of estrogen active compounds (EAC). As environmental samples like waste water also contain blue fluorescent components, it is difficult to differentiate them from pYES signals. Therefore, resorufin-β-d-galactopyranoside (RGP), providing the orange fluorescing resorufin after enzymatic cleavage, was introduced as pYES substrate to determine EAC.

High-performance thin-layer chromatography (HPTLC) for the simultaneous quantification of the cyclic lipopeptides Surfactin, Iturin A and Fengycin in culture samples of Bacillus species.

A high-performance thin-layer chromatography method has been established for the identification and simultaneous quantification of the cyclic lipopeptides Surfactin, Iturin A and Fengycin in Bacillus culture samples. B. subtilis DSM 10, B.

How Do Modern Pesticide Treatments Influence the Mobility of Old Incurred DDT Contaminations in Agricultural Soils?

Even more than 50 years after the ban of DDT in Germany, farmers are still affected by its persistence in contaminated soils. Depending on the crop cultivated on such soils, this often leads to low-level residues of DDT and its metabolites DDE and DDD ("DDX"), which are perceived as a risk by the food value chain. Pesticide formulations used in modern agriculture commonly contain high levels of surfactants, but so far no open-field studies have evaluated the effects of these treatments on the mobility of lipophilic contaminants, such as DDX.

Determination of 2-Aminoacetophenone in wine by high-performance thin-layer chromatography-fluorescence detection.

2-Aminoacetophenone (AAP) is closely correlated with the appearance of the sensory phenomenon of UTA ("untypical aging off-flavor") in wine. AAP analyses are generally performed by gas chromatography and mass selective detection (GC/MS), when AAP is extracted from wines by liquid-liquid, solid-liquid or solid phase microextraction. Here we present a rapid, selective and sensitive method for the determination of AAP in wine by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD).

Extracellular aromatic biosurfactant produced by Tsukamurella pseudospumae and T. spumae during growth on n-hexadecane.

Biosurfactants are surface-active agents produced by microorganisms and show increasing significance in various industrial applications. A great variety of these secondary metabolites are described to occur within actinomycetes, amongst trehalose lipids and oligosaccharide lipids produced by the family Tsukamurellaceae. This study reports on the production of not yet described compounds with surface active behavior by non-pathogenic Tsukamurella pseudospumae and Tsukamurella spumae during growth on hydrophobic carbon sources.

Photostability of cosmetic UV filters on mammalian skin under UV exposure.

Previous studies showed that the common UV filter substances benzophenone-3 (BP-3), butyl methoxydibenzoylmethane (BM-DBM), octocrylene (OCR), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate (EHS) and ethylhexyl triazone (EHT) were able to react with amino side chains of different proteins in vitro. To transfer the results to mammalian skin conditions, sunscreen products were applied on both prepared fresh porcine skin and glass plates, followed by UV irradiation and the determination of depletion of the respective UV filters. Significantly lower recoveries of the UV filters extracted from skin samples than from glass plates indicated the additional reaction of the UV filters with skin constituents, when proteins will be the most important reactants.

Photooxidation of tryptophan leading to 2-aminoacetophenone--a possible reason for the untypical aging off-flavor in wine.

2-Aminoacetophenone (AAP) was recognized as the key compound for the so-called untypical aging off-flavor (UTA) in Vitis vinifera wines. In this study, it was shown that AAP can be formed by photooxidation of free and protein-bound tryptophan (TRP) in combination with a subsequent storage in model wine. Solutions of TRP and lysozyme were exposed to artificial sunlight both in the presence and in the absence of the photosensitizer riboflavin.

High-performance thin-layer chromatography screening of multi class antibiotics in animal food by bioluminescent bioautography and electrospray ionization mass spectrometry.

The world-wide usage and partly abuse of veterinary antibiotics resulted in a pressing need to control residues in animal-derived foods. Large-scale screening for residues of antibiotics is typically performed by microbial agar diffusion tests. This work employing high-performance thin-layer chromatography (HPTLC) combined with bioautography and electrospray ionization mass spectrometry introduces a rapid and efficient method for a multi-class screening of antibiotic residues.

Planar solid phase extraction clean-up and microliter-flow injection analysis-time-of-flight mass spectrometry for multi-residue screening of pesticides in food.

For multi-residue analysis of pesticides in food, a sufficient clean-up is essential for avoiding matrix effects in liquid and gas chromatography (LC and GC) analysis coupled to mass spectrometry (MS). In the last two years, high-throughput planar solid phase extraction (HTpSPE) was established as a new clean-up concept for pesticide residue analysis in fruits and vegetables (C. Oellig, W.

Rapid and selective determination of multi-sulfonamides by high-performance thin layer chromatography coupled to fluorescent densitometry and electrospray ionization mass detection.

In the European Union (EU), sulfonamides are among the most widely administrated groups of antibiotics in animal husbandry. Therefore, monitoring their residues in edible animal tissues plays an important role in the EU food safety framework. In this work, a simple and efficient method for the rapid screening of twelve prior sulfonamides frequently prescribed as veterinary drugs by high-performance thin-layer chromatography (HPTLC) was established.