@article{RohnerFreyMothesetal.2011,
  author    = {Rohner, Fabian and Frey, Simone K. and Mothes, Ralf and Hurtienne, Andrea and Hartong, Simone and Bosso, Patrice Emery and Bui, Mai and Schweigert, Florian J. and Northrop-Clewes, Christine},
  title     = {Quantification of vitamin A in palm oil using a fast and simple portable device method validation and comparison to high-performance liquid chromatography},
  series = {International journal for vitamin and nutrition research},
  volume    = {81},
  journal   = {International journal for vitamin and nutrition research},
  number    = {5},
  publisher = {Hogrefe},
  address   = {Bern},
  issn      = {0300-9831},
  doi       = {10.1024/0300-9831/a000081},
  pages     = {335 -- 342},
  year      = {2011},
  abstract  = {Vitamin A deficiency continues to be a global public health problem. Fortification of oil with vitamin A is considered a cost-effective, feasible strategy to prevent this problem but quality control poses a challenge to program implementation. To overcome this, we have validated a newly developed device that quantitatively measures the content of retinyl palmitate in refined palm oil, is simple to use, and yields immediate results. Linearity of analysis rand from 2.5-30 mg retinol equivalents (RE)/kg of palm oil, with 2.5 mg RE/kg being the determination limit; inter- and intra-assay precision ranged from 1.4-7.1 To. Comparison with a high-performance Liquid chromatography method showed high agreement between the methods (R-2 = 0.92; Limits of Agreement: -1.24 mg to 2.53 mg RE/kg), and further comparisons illustrate that the new device is useful in low resource settings. This device offers a field- and user-friendly solution to quantifying the vitamin A content in refined palm oil.},
  language  = {en}
}
@article{RailaEnjalbertMothesetal.2012,
  author    = {Raila, Jens and Enjalbert, Francis and Mothes, Ralf and Hurtienne, Andrea and Schweigert, Florian J.},
  title     = {Validation of a new point-of-care assay for determination of ss-carotene concentration in bovine whole blood and plasma},
  series = {Veterinary clinical pathology},
  volume    = {41},
  journal   = {Veterinary clinical pathology},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {0275-6382},
  doi       = {10.1111/j.1939-165X.2012.00400.x},
  pages     = {119 -- 122},
  year      = {2012},
  abstract  = {Background: beta-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. beta-Carotene concentrations in plasma are used to optimize beta-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure beta-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). Objective: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring beta-carotene in whole blood and plasma. Methods: beta-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). Results: Concentrations of beta-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean +/- SD; n = 166): HPLC-plasma 4.23 +/- 2.35 mg/L; POC-plasma 4.49 +/- 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 +/- 2.12 mg/L; POC-whole blood 3.67 +/- 2.29 mg/L. Conclusions: Concentrations of beta-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding beta-carotene deficiency facilitates rapid and appropriate optimization of beta-carotene supplementation in feed.},
  language  = {en}
}
@article{RohnerGarrettLaillouetal.2012,
  author    = {Rohner, Fabian and Garrett, Greg S. and Laillou, Arnaud and Frey, Simone K. and Mothes, Ralf and Schweigert, Florian J. and Locatelli-Rossi, Lorenzo},
  title     = {Validation of a user-friendly and rapid method for quantifying iodine content of salt},
  series = {Food and nutrition bulletin},
  volume    = {33},
  journal   = {Food and nutrition bulletin},
  number    = {4},
  publisher = {International Nutrition Foundation},
  address   = {Boston},
  issn      = {0379-5721},
  pages     = {S330 -- S335},
  year      = {2012},
  abstract  = {Background. Despite considerable progress made in the past decade through salt iodization programs, over 2 billion people worldwide still have inadequate iodine intake, with devastating consequences for brain development and intellectual capacity. To optimize these programs with regard to salt iodine content, careful monitoring of salt iodine content is essential, but few methods are available to quantitatively measure iodine concentration in a simple, fast, and safe way. Objective. We have validated a newly developed device that quantitatively measures the content of potassium iodate in salt in a simple, safe, and rapid way. Methods. The linearity, determination and detection limit, and inter- and intra-assay variability of this colorimetric method were assessed and the method was compared with iodometric titration, using salt samples from several countries. Results. Linearity of analysis ranged from 5 to 75 mg/kg iodine, with I mg/kg being the determination limit; the intra- and interassay imprecision was 0.9\%, 0.5\%, and 0.7\% and 1.5\%, 1.7\%, and 2.5\% for salt samples with iodine contents of 17, 30, and 55 mg/kg, respectively; the interoperator imprecision for the same samples was 1.2\%, 4.9\%, and 4.7\%, respectively. Comparison with the iodometric method showed high agreement between the methods (R-2 = 0.978; limits of agreement, -10.5 to 10.0 mg/kg). Conclusions. The device offers a field- and user-friendly solution to quantifying potassium iodate salt content reliably. For countries that use potassium iodide in salt iodization programs, further validation is required.},
  language  = {en}
}
@article{SchweigertGerickeMothes2003,
  author    = {Schweigert, Florian J. and Gericke, Beate and Mothes, Ralf},
  title     = {Lebensmittelanalytik mittels SELDI-TOF-MS},
  year      = {2003},
  language  = {de}
}