@article{SeigelMilzSpangenberg2013,
  author    = {Andrea Seigel and Barbara Milz and Bernd Spangenberg},
  title     = {Quantification of Parabens by Diode-Array Thin-Layer Chromatography Coupled with a Vibrio fischeri Bioluminescence Assay},
  series   = {Journal of Planar Chromatography},
  volume    = {26},
  number    = {2/2013},
  issn      = {0933-4173 (Print)},
  pages     = {119 -- 124},
  year      = {2013},
  abstract  = {We present a video-densitometric quantification method in combination with diode-array quantification for the methyl-, ethyl-, propyl-, and butylparaben in cosmetics. These parabens were separated on cyanopropyl bonded plates using water-acetonitrile-dioxane-ethanol-NH3 (25\%) (8:2:1:1:0.05, v/v) as mobile phase. The quantification is based on UV-measurements at 255 nm and a bioeffectively-linked analysis using Vibrio fischeri bacteria. Within 5 min, a Tidas S 700 diode-array scanner (J\&M, Aalen, Germany) scans 8 tracks and thus measures in total 5600 spectra in the wavelengths range from 190 to 1000 nm. The quantification range for all these parabens is from 20 to 400 ng per band, measured at 255 nm. In the V. fischeri assay a CCD-camera registers the white light of the light-emitting bacteria within 10 min. All parabens effectively suppress the bacterial light emission which can be used for quantifying within a linear range from 100 to 400 ng. Measurements were carried out using a 16-bit MicroChemi chemiluminescence system (biostep GmbH, Jahnsdorf, Germany), using a CCD camera with 4.19 megapixels. The range of linearity is achieved because the extended Kubelka-Munk expression was used for data transformation. The separation method is inexpensive, fast, and reliable.},
  language  = {en}
}