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The strong dependence of separation behavior on ultrathin-layer chromatography (UTLC) stationary phase microstructure motivates continued UTLC plate design optimization efforts. We fabricated 4.6-5.3 [micro]m thick normal phase silica UTLC stationary phases with several types of in-plane macropore anisotropies using the glancing angle deposition (GLAD) approach to engineering nanostructured thin films. The separation behaviors of two new media, isotropic vertical posts and anisotropic bladelike films, were compared to that of anisotropic chevron media. Channel-like structures within the anisetropic media introduced preferential mobile phase flow directions that could be exploited to give separation tracks diagonal to the development direction. Extraction of chromatograms from these angled tracks required the development of a now analytical approach that involved a commercial flatbed film scanner and custom numerical image analysis software. GLAD stationary phase performance was quantified using the Dimethyl Yellow dye separated from a lipophilic dye mixture over migration distances leas than ~10 mm. The limits of detection were 10 [+ or -] 4 ng for the vertical pests and 11 [+ or -] 3 ng for the bladelike media. We obtained theoretical plate heights that varied with film microstructure between 12 and 28 [micro]m. Unoptimized separation performance was comparable to that of other planar chromatography media. Macropore anisotropies engineered by GLAD may expand the capabilities of future UTLC stationary phases. 10.1021/ac101004b

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. It is suited for sustainable atline analysis as it combines all planar chromatography tasks, allowing low-cost quality control in milling plants. The LOD and LOQ of ergocristine were determined to be 0.4 and 1.2 ng/zone, respectively. Detectability of ergot alkaloids was proven to be below the current maximum limit of 500 µg/kg for rye milling products. The repeatability (%RSD) was 4.1 % and the coefficient of determination of the analytical response (R 2 ) was 0.9918 for ergocristine. The mean recovery rate of ergot alkaloids in spiked whole rye grain was close to 100 %. Results of screening whole rye for ergot alkaloids were successfully verified by comparison with those obtained by conventional status quo HPTLC instrumentation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

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. As examples, saccharides were analyzed in eight products of different matrix complexity, and the absence of lactose was studied in nine lactose-free dairy products. Derivatization including homogeneous reagent application and plate heating via the 2LabsToGo system was explored for saccharide detection, and its performance was investigated. The visual detection sensitivity of lactose was comparable to previous studies. The precision of lactose in milk matrix (%RSD 4.6%) as well as the coefficient of determination of the calibration function (0.9995) were highly satisfying. The obtained lactose content of milk (4.5%) was plausible. Screening eight saccharide-containing food samples showed the saccharides in agreement with the expectations for the respective food product. The lactose content of nine different lactose-free dairy products was proven to be below the 0.1% lactose limit value. As proof-of-principle and for verification, these screening results obtained with the miniaturized 2LabsToGo system were reproduced using conventional state-of-the-art instrumentation, which led to the same results. However, instrumental costs were comparably low for the 2LabsToGo system. The application of the new 2LabsToGo system was successfully shown for saccharide screening, which is attractive to the field of quality control or official food control., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

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. Among the thousands of compounds therein, it is often not clear which compounds are the important ones. On the same separation surface, additional detection of biological effects enables and guides substance prioritization. The newly developed open-source 2LabsToGo system for chemical and biological analysis is completely solvent-resistant and, due to miniaturization, environmentally friendly regarding the consumption of materials. It produces comparable results but is 10 times more compact (26 cm × 31 cm × 34 cm), 10 times lighter (6.8 kg), and 55 times less expensive (€ 1717) than current sophisticated commercial devices. As a proof of concept of the first 2LabsToGo system, the quality of different water samples was analyzed since clean water is becoming increasingly rare. In water, most of the thousands of substance signals or features can neither be identified nor classified toxicologically. However, methods that exploit this hyphenated strategy provide answers to such essential safety issues. Drinking or tap water did not show bioactive or toxic compounds, which was expected, whereas biogas or landfill water samples did. The hyphenated 2LabsToGo strategy is affordable and extremely useful for all laboratories with limited equipment but pressing challenges. It is ready to be used in various analytical tasks and applications.

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. For inkjet printing of solutions, a newly designed printhead was manufactured controlled by a self-constructed ink-jet board, allowing to check the nozzles' resistance heating circuit. Plate heating was newly integrated, especially favorable for the demonstrated application of higher volumes of aqueous samples. The UV/Vis/FLD plate images were captured by a Raspberry Pi V2 camera module under illumination by novel light emitting diodes (LEDs) for highly selective RGBW color (Vis), UVC 278-nm (UV) and UVA 366-nm (FLD) detection, installed in a newly created miniature cabinet to protect from extraneous light. The spectral separation of differently colored food dyes was achieved by the fully addressable driver controlled RGBW LEDs. The software was newly written in R to speed-up the processes, supported by the new Raspberry Pi 4B computer with 4 GB RAM. The analysis of Stevia leaves for steviol glycosides yielded results comparable to the status quo. Different water samples were analyzed for bioactive compounds. Thereby, compounds of general cytotoxicity were effect-directed detected by bioluminescent A. fischeri bacteria. It allowed the bioanalytical screening for potential risks in tap water, surface waters, rain water, landfill leachates and biogas slurries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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. This effect-image was uploaded as a template in the updated TLC-MS_manager software. The clicked-on antibiotic zones were sequentially eluted without intervention from the planar counterpart (without bioassay) via a monolithic HPLC column into the HRMS system. For elution of antibiotics of 7 structural classes at 5 different calibration levels, the new on-surface autosampler achieved intra-day precisions of 2.1-14.1%, while inter-day precisions ranged 2.5-16.1% (all n = 3). The new hyphenation offers potential for planar sample clean-up prior to HPLC, concentration of liquid samples, increase of peak capacity and proof of peak purity or isomers. The integrated autoTLC-LC-MS system enabled high sample throughput, efficiency and reproducibility for the first time through fully automated TLC-LC-MS sequence operation. Its contact-closure signal functionality, versatile 3D printed planar sample holder and open-source software made it readily adjustable for new analytical tasks. Undoubtedly, any planar material can be investigated for leachables, such as textiles, foils, papers and other packagings, as well as planar biological samples for ingredients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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. The sample extracts were analyzed by HPTLC-FLD on silica gel LiChrospher plates with n-pentane/n-hexane/diethyl ether (22.5:22.5:55, v/v/v) as mobile phase, when interfering matrix like cholesterol and triacylglycerols were successfully separated from the E 471 food additives. For quantitation, an emulsifier with known composition was used as calibration standard and the fluorescent MAG and DAG were scanned at 366/> 400 nm. Limits of detection and quantitation of 4 and 11 mg/100 g aerosol whipping cream were obtained for both monostearin and 1,2-distearin, respectively, and allowed the reliable quantitation of MAG and DAG from E 471 far below commonly applied emulsifier amounts. Recoveries from model aerosol whipping cream with 400 mg E 471/100 g were determined in a calibration range of 200-600 mg E 471/100 g sample and ranged between 86 and 105% with relative standard deviations below 7%. In aerosol whipping creams from the German market, E 471 amounts ranged between 384 and 610 mg/100 g.

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. Free and total fruit acids were determined by reversed phase HPLC-UV analysis of untreated and saponified emulsifier extracts with 20 mM potassium hydrogen phosphate buffer (pH 2.6) as isocratic eluent. Limits of quantitation of 0.08-0.27 g free fruit acid/kg emulsifier and 4-14 g total fruit acid/kg granted a reliable method with recoveries for free and total fruit acids between 80 and 100% with relative standard deviations (%RSD) below 4%. For the quantitation of free glycerol by spectrophotometry, an enzymatic assay was optimized for the analysis of E 472 providing reliable results with %RSD values below 9%. In addition, the ash content of E 472 emulsifiers was determined., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

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. Here we present an innovative and sensitive method for the characterization of the composition of E 472 emulsifiers by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD). For HPTLC-FLD, technical emulsifiers were simply dissolved and analyzed on HPTLC silica gel plates after a two-fold development and derivatization with primuline, enabling the easy characterization and direct visual comparison of the emulsifier pattern (fingerprint) through the fluorescent lipid components under UV 366 nm. Thus, the HPTLC-FLD fingerprint approach represents a simple tool for the comparison of different samples, batches and categories of E 472. Coupling of HPTLC to mass spectrometry moreover enabled the identification of constituents of interest., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)