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://academic.oup.com/jaoac/article/101/5/1397/5654074 SN - 1060-3271 SS - 1060-3271 U6 - https://doi.org/10.5740/jaoacint.18-0054 DO - https://doi.org/10.5740/jaoacint.18-0054 VL - 101 IS - 5 SP - 1397 EP - 1401 ER -