TY  - JOUR
A1  - Wiesen, Sebastian
A1  - Tippkötter, Nils
A1  - Muffler, Kai
A1  - Suck, Kirstin
A1  - Sohling, Ulrich
A1  - Ruf, Friedrich
A1  - Ulber, Roland
T1  - Adsorption of fatty acids to layered double hydroxides in aqueous systems
JF  - Adsorption
N2  - Due to their anion exchange characteristics, layered double hydroxides (LDHs) are suitable for the detoxification of aqueous, fatty acid containing fermentation substrates. The aim of this study is to examine the adsorption mechanism, using crude glycerol from plant oil esterification as a model system. Changes in the intercalation structure in relation to the amount of fatty acids adsorbed are monitored by X-ray diffraction and infra-red spectroscopy. Additionally, calcination of LDH is investigated in order to increase the binding capacity for fatty acids. Our data propose that, at ambient temperature, fatty acids can be bound to the hydrotalcite by adsorption or in addition by intercalation, depending on fatty acid concentration. The adsorption of fatty acids from crude glycerol shows a BET-like behavior. Above a fatty acid concentration of 3.5 g L−1, intercalation of fatty acids can be shown by the appearance of an increased interlayer spacing. This observation suggests a two phase adsorption process. Calcination of LDHs allows increasing the binding capacity for fatty acids by more than six times, mainly by reduction of structural CO32−.
Y1  - 2015
VL  - 21
IS  - 6-7
SP  - 459
EP  - 466
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Muffler, Kai
A1  - Tippkötter, Nils
A1  - Ulber, Roland
ED  - Timmis, Kenneth N.
T1  - Chemical feedstocks and fine chemicals from other substrates
T2  - Handbook of hydrocarbon and lipid microbiology. Volume 4:  Consequences of microbial interactions with hydrocarbons, oils and lipids. - (Springer reference)
Y1  - 2010
SN  - 978-3-540-77588-1
U6  - http://dx.doi.org/10.1007%2F978-3-540-77587-4_214
SP  - 2891
EP  - 2902
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Stückmann, Henning
A1  - Kroll, Stephen
A1  - Winkelmann, Gunda
A1  - Noack, Udo
A1  - Scheper, Thomas
A1  - Ulber, Roland
T1  - A semi-quantitative dipstick assay for microcystin
JF  - Analytical and Bioanalytical Chemistry
N2  - An immunochromatographic lateral flow dipstick assay for the fast detection of microcystin-LR was developed. Colloid gold particles with diameters of 40 nm were used as red-colored antibody labels for the visual detection of the antigen. The new dipstick sensor is capable of detecting down to 5 µg·l−1 (ppb; total inversion of the color signal) or 1 ppb (observation of color grading) of microcystin-LR. The course of the labeling reaction was observed via spectrometric wave shifts caused by the change of particle size during the binding of antibodies. Different stabilizing reagents showed that especially bovine serum albumin (BSA) and casein increase the assays sensitivity and the conjugate stability. Performance of the dipsticks was quantified by pattern processing of capture zone CCD images. Storage stability of dipsticks and conjugate suspensions over 115 days under different conditions were monitored. The ready-to-use dipsticks were successfully tested with microcystin-LR-spiked samples of outdoor drinking- and salt water and applied to the tissue of microcystin-fed mussels.
Y1  - 2009
U6  - http://dx.doi.org/10.1007/s00216-009-2750-8
SN  - 1618-2650
VL  - 394
IS  - 3
SP  - 863
EP  - 869
PB  - springer
CY  - Berlin
ER  -