TY  - JOUR
A1  - Villatoro, José Andrés
A1  - Zühlke, Martin
A1  - Riebe, Daniel
A1  - Beitz, Toralf
A1  - Weber, Marcus
A1  - Riedel, Jens
A1  - Löhmannsröben, Hans-Gerd
T1  - IR-MALDI ion mobility spectrometry: physical source characterization and application as HPLC detector
JF  - International journal for ion mobility spectrometry : official publication of the International Society for Ion Mobility Spectrometry
N2  - Infrared matrix-assisted laser dispersion and ionization (IR-MALDI) in combination with ion mobility (IM) spectrometry enables the direct analysis of biomolecules in aqueous solution. The release of ions directly from an aqueous solution is based on a phase explosion, induced by the absorption of an IR laser pulse, which disperses the liquid as vapor, nano-and micro-droplets. The ionization process is characterized initially by a broad spatial distribution of the ions, which is a result of complex fluid dynamics and desolvation kinetics. These processes have a profound effect on the shape and width of the peaks in the IM spectra. In this work, the transport of ions by the phase explosion-induced shockwave could be studied independently from the transport by the electric field. The shockwave-induced mean velocities of the ions at different time scales were determined through IM spectrometry and shadowgraphy. The results show a deceleration of the ions from 118 m.s(-1) at a distance of 400 mu m from the liquid surface to 7.1 m.s(-1) at a distance of 10 mm, which is caused by a pile-up effect. Furthermore, the desolvation kinetics were investigated and a first-order desolvation constant of 325 +/- 50 s(-1) was obtained. In the second part, the IR-MALDI-IM spectrometer is used as an HPLC detector for the two-dimensional separation of a pesticide mixture.
KW  - Ion mobility spectrometry
KW  - IR-MALDI
KW  - Shadowgraphy
KW  - Laser
KW  - Imaging
KW  - HPLC
Y1  - 2016
U6  - https://doi.org/10.1007/s12127-016-0208-1
SN  - 1435-6163
SN  - 1865-4584
VL  - 19
SP  - 197
EP  - 207
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Islam, Khan Shaiful
A1  - Khalil, Mahmoud
A1  - Männer, K.
A1  - Raila, Jens
A1  - Rawel, Harshadrai Manilal
A1  - Zentek, J.
A1  - Schweigert, Florian J.
T1  - Effect of dietary alpha-tocopherol on the bioavailability of lutein in laying hen
JF  - Journal of animal physiology and animal nutrition
N2  - Lutein and its isomer zeaxanthin have gained considerable interest as possible nutritional ingredient in the prevention of age-related macular degeneration (AMD) in humans. Egg yolk is a rich source of these carotenoids. As an oxidative sensitive component, antioxidants such as -tocopherol (T) might contribute to an improved accumulation in egg yolk. To test this, chickens were fed lutein esters (LE) with and without -tocopherol as an antioxidant. After depletion on a wheat-soya bean-based lutein-poor diet for 21days, laying hens (n=42) were equally divided into three groups and fed the following diets for 21days: control (basal diet), a LE group (40mg LE/kg feed) and LE+T group (40mg LE plus 100mg T/kg feed). Eggs and blood were collected periodically. Carotenoids and -tocopherol in yolk and blood plasma were determined by HPLC. Egg yolk was also analysed for total carotenoids using a one-step spectrophotometric method (iCheck(())). Lutein, zeaxanthin, -tocopherol and total carotenoids in egg yolk were highest after 14days of feeding and decreased slightly afterwards. At the end of the trial, eggs of LE+T group contained higher amount of lutein (13.72), zeaxanthin (0.65), -tocopherol (297.40) and total carotenoids (21.6) compared to the LE group (10.96, 0.55, 205.20 and 18.0mg/kg, respectively, p<0.05). Blood plasma values of LE+T group contain higher lutein (1.3), zeaxanthin (0.06) and tocopherol (20.1) compared to LE group (1.02, 0.04 and 14.90mg/l, respectively, p<0.05). In conclusion, dietary -tocopherol enhances bioavailability of lutein reflecting higher content in egg yolk and blood plasma. Improved bioavailability might be due to increased absorption of lutein in the presence of tocopherol and/or a greater stability of lutein/zeaxanthin due to the presence of -tocopherol as an antioxidant.
KW  - carotenoids
KW  - tocopherol
KW  - egg yolk
KW  - bioavailability
KW  - HPLC
KW  - iCheck
Y1  - 2016
U6  - https://doi.org/10.1111/jpn.12464
SN  - 0931-2439
SN  - 1439-0396
VL  - 100
SP  - 868
EP  - 875
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -