TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Milz, Barbara A1 - Bin Idros, Idzaid A1 - Spangenberg, Bernd T1 - Limits of quantification of some neonicotinoid insecticides measured by thin-layer chromatography JF - Journal of Liquid Chromatography & Related Technologies N2 - A simple method to quantify the neonicotinoid insecticides nitenpyram, thiamethoxam, acetamiprid, imidacloprid, thiacloprid and clothianidin directly on an HPTLC-plate is presented. As stationary phase silica gel 60 RP-18WF254 s plates were used and a mixture of methyl-t-butyl ether, 2-butanone, NH3 (25%) (5 + 2+0.1, v/v) was used as solvent. All neonicotinoid insecticides show light absorptions below 300 nm. The calculated limits of quantification (LOQ) by UV-detection are in the range from 12 ng to 26 ng on plate depending on the different insecticides.Nitenpyram can be stained using fast blue salt B, forming red zones. The observed LOQ is 25 ng on plate. Acetamiprid can be specifically stained using phenylglyoxylic acid forming a yellow/green fluorescent compound. The LOQ is 52 ng per spot.The compounds thiamethoxam, acetamiprid, thiacloprid and clothianidin can be transformed into blue fluorescing zones, using a relatively new staining solution. This consists of tetraphenylborate and HCl. This is the first publication mentioning that neonicotinoids undergo this reaction. The calculated limits of quantification are in the range from 10 ng to 27 ng on plate.A simple pre-treatment procedure using an acetonitrile extraction and a Chromabond SiOH clean up procedure leads to overall LOQs for bee samples of 48 to 108 µg/Kg. The method can be used to measure neonicotinoid contaminations of bees. KW - Dünnschichtchromatographie KW - Insektizid KW - Belastung KW - Biene Y1 - 2012 SN - 1082-6076 DO - https://dx.doi.org/10.1080/10826076.2012.676842 VL - 35 IS - 10 SP - 1404 EP - 1414 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Minar, Yvonne Anna A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Is Equol an Ecologically Relevant Endocrine Disruptor? Equol Determination in Cattle Manure by Effect-Directed Analysis Using the pYES Test JF - Journal of Planar Chromatography N2 - We present a planar chromatographic separation method for the phytoestrogenic active compound equol, separated on RP-18 W (Merck, 1.14296) phase. It could be shown that an ethanolic cattle manure extract contains this phytoestrogenic active compound to a larger amount. As solvents for the mobile phase, hexane, ethyl acetate, and acetone (45:15:10, v/v); acetone and water (15:10, v/v); and n-hexane, CH2Cl2, ethyl acetate, methanol, and formic acid (40:40:20:5:1, v/v) have been used. After separation, a modified yeast estrogen screen (YES) test was applied, using the yeast strain Saccharomyces cerevisiae BJ3505 containing an estrogen receptor. Its activation by equol induces the reporter gene lacZ which encodes the enzyme β-galactosidase. The enzyme activity is measured directly on the TLC plate by using the substrate MUG (4-methylumbelliferyl-β-d-galactopyranoside) or the substrate X-β-Gal (5-bromo-4-chloro-3-indoxyl-β-d-galactopyranoside). β-Galactosidase cleaves MUG into a fluorescing compound. X-β- Gal is also hydrolyzed and then oxidized by oxygen forming the deep-blue dye 5,5′-dibromo-4,4′-dichloro-indigo. Both reactions in combination with a thin-layer chromatography (TLC) separation allow very specific detecting of equol in cattle manure, although that is a very challenging matrix. Preliminary results show that the average content of equol in liquid manure is roughly 60 μg g−1. The value for urine is 50 μg mL−1. KW - High-performance thin-layer chromatography KW - Thin-layer chromatography KW - Phytoestrogen equol KW - Equol in cattle manure KW - Effect-directed analysis KW - Yeast estrogen screen assay Y1 - 2018 SN - 0933-4173 DO - https://dx.doi.org/10.1556/1006.2018.31.1.9 VL - 31 IS - 1 SP - 72 EP - 78 PB - Budapest CY - Budapest ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Milz, Barbara A1 - Schnurr, Philip A1 - Grafmüller, Jannis A1 - Oehler, Kevin A1 - Spangenberg, Bernd T1 - A Validated Quantification of Sudan Red Dyes in Spicery using TLC and a 16-bit Flatbed Scanner JF - Journal of AOAC International N2 - We present a video-densitometric quantification method for Sudan red dyes in spices and spice mixtures, separated by TLC. Application was done band-wise in small dots using a 5 μL glass pipette. For separation, the RP-18 plates (20 × 20 cm with fluorescent dye; Merck, Germany, 1.05559) were developed in a vertical developing chamber without vapor saturation from the starting point to a distance of 70 mm by using acetonitrile, methanol, and aqueous ammonia solution (25%; 8 + 1.8 + 0.2, v/v) as mobile phase. The quantification is based on direct measurements using an inexpensive 16-bit flatbed scanner for color measurements (in red, green, and blue). Evaluation of only the green channel makes the measurements very specific. For linearization, an extended Kubelka-Munk expression for data transformation was used. The range of linearity covers more than two magnitudes and lies between 20 and 500 ng. The extraction from a 2 g sample with acetonitrile, evaporation, and reconstitution to 200 μL with methanol and the band-wise application (7 mm) of a 10 μL sample allows a statistically defined LOD of less than 500 ppb of Sudan red dyes. To perform the analysis, a separation chamber, RP-18 plates, 5 μL glass pipettes, and a 16-bit flatbed scanner for 105 € are needed; therefore, the separation method is inexpensive, fast, and reliable. Y1 - 2018 UR - https://aoac.publisher.ingentaconnect.com/contentone/aoac/jaoac/2018/00000101/00000005/art00014 SN - 1060-3271 DO - https://dx.doi.org/10.5740/jaoacint.18-0054 VL - 101 IS - 5 SP - 1397 EP - 1401 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Witos, Yvonne Anna A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Two-Dimensional Thin-Layer Chromatography of 17α-Ethinylestradiol on RP-18 W Plate, Detected by Effect-Directed Analysis Using the YES Test. JF - Journal of Planar Chromatography Y1 - 2017 SN - 0933-4173 IS - 30 SP - 136 EP - 141 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - 2D-Thin-Layer Chromatography (2D-TLC) Flash Test of 17α-Ethinylestradiol and related Steroids detected by Fluorescence Densitometry JF - Journal of liquid chromatography & related technologies KW - Dünnschichtchromatographie Y1 - 2013 SN - 1082-6076 VL - 36 IS - 17 SP - 2378 EP - 2386 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Seigel, Andrea A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Quantification of Parabens by Diode-Array Thin-Layer Chromatography Coupled with a Vibrio fischeri Bioluminescence Assay JF - Journal of Planar Chromatography KW - Dünnschichtchromatographie KW - Biolumineszenz Y1 - 2013 SN - 0933-4173 VL - 26 IS - 2/2013 SP - 119 EP - 124 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - nicht begutachtet (unreviewed) A1 - Humpert, Désirée A1 - Milz, Barbara A1 - Lotz, Andreas A1 - Spangenberg, Bernd T1 - Thin-Layer Chromatographic Separation and In Situ Chemiluminescence of Phenolic Compounds KW - Dünnschichtchromatographie KW - Lumineszenz KW - Phenol Y1 - 2016 DO - https://dx.doi.org/10.1556/1006.2016.29.4.11 SP - 318 EP - 322 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Lotz, Andreas A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - A New and Sensitive TLC Method to Measure Trans-Resveratrol in Red Wine JF - Journal of liquid chromatography & related technologies KW - Dünnschichtchromatographie KW - Resveratrol Y1 - 2015 SN - 1082-6076 DO - https://dx.doi.org/10.1080/10826076.2015.1028288 VL - 38 IS - 11 Special Issue: Thin-Layer Chromatography SP - 1104 EP - 1108 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - A Validated Quantification of Benzocaine in Lozenges Using TLC and a Flatbed Scanner JF - Chromatographia KW - Dünnschichtchromatographie KW - Benzocain Y1 - 2013 SN - 0009-5893 DO - https://dx.doi.org/10.1007/s10337-013-2436-4 VL - 76 IS - 19-20 Special Issue/2013 SP - 1307 EP - 1313 ER - TY - CHAP U1 - Konferenzveröffentlichung A1 - Lotz, Andreas A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Chemiluminescence and TLC : A successful combination T2 - 21th International Symposium on Separation Science, June 30th - July 3rd, 2015 in Ljubljana, Slovenia: Book of Abstracts KW - Lumineszenz KW - Dünnschichtchromatographie Y1 - 2015 SP - 37 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Grafted 2D-Thin Layer Chromatography (2D-TLC) of 17α-Ethinylestradiol detected by Bio-directed Analysis JF - Journal of Liquid Chromatography & Related Technologies N2 - We present a two dimensional (2D) planar chromatographic separation of estrogenic active compounds on RP-18 (Merck, 1.05559) and silica gel (Merck, 1.05721) phase. A mixture of 13 substances was separated using a solvent mix consisting of methanol–acetonitrile–water (2 + 2 + 1, v/v/v) on RP-18 phase in the first direction and cyclohexane–butylacetate–methanol (8 + 6 + 1, v/v/v) in the second direction on silica gel plate. Both developments were carried out over a distance of 70 mm. We used the grafted method to combine both plates in a 2D-separation. This 2D-separation method can be used to quantify 17α-ethinylestradiol (EE2) in an effect-directed analysis using the yeast strain Saccharomyces cerevisiae BJ3505. The test strain (according to McDonnell) contains the estrogen receptor. Its activation by estrogen active compounds is measured by inducting the reporter gene lacZ that encodes the enzyme ß-galactosidase. This enzyme activity is determined on plate by using the fluorescent substrate MUG (4-methylumbelliferyl ß-D-galactopyranoside). KW - Dünnschichtchromatographie KW - Polymerisation KW - Ethinylestradiol KW - Analyse Y1 - 2014 SN - 1082-6076 DO - https://dx.doi.org/10.1080/10826076.2014.907109 VL - 37 IS - 20 SP - 2872 EP - 2881 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - nicht begutachtet (unreviewed) A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Schnelle Analyse vor Ort : Moderne Auswertung in der Dünnschichtchromatographie T2 - CITplus - Das Praxismagazin für Verfahrens- und Chemieingenieure Y1 - 2012 SN - 1436-2597 VL - 15 IS - 7-8 SP - 43 EP - 44 ER - TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - nicht begutachtet (unreviewed) A1 - Milz, Barbara A1 - Spangenberg, Bernd T1 - Schnelle Analyse vor Ort. Moderne Auswertung in der Dünnschichtchromatographie T2 - GIT KW - Kardiale Resynchronisationstherapie Y1 - 2013 VL - 57 IS - 8 SP - 384 EP - 385 ER -