title: Screening for Ricinoleic Acid as a Chemical Marker for Secale cornutum in Rye by High-Performance Thin-Layer Chromatography with Fluorescence Detection.
abstract: Ricinoleic acid as the characteristic fatty acid of Secale cornutum oil is a good marker for Secale cornutum impurities in cereal. The presented screening for ricinoleic acid in rye by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD) offers a selective and sensitive method for the determination of Secale cornutum and is very different from existing gas chromatographic analyses. Lipid extraction was followed by transesterification and solid-phase extraction cleanup; thereafter, extracts were selectively derivatized with 2-naphthoyl chloride and analyzed by HPTLC-FLD with silica gel plates and cyclohexane/diisopropyl ether/formic acid (86:14:1, v/v/v) as mobile phase. For quantitation, the enhanced fluorescence was scanned at 280/>340 nm. Limits of detection and quantitation of 0.1 and 0.4 mg ricinoleic acid/kg of rye were obtained, which enables the determination of Secale cornutum far below the maximum admitted level. With near-100% recoveries and low standard deviations at relevant spiking levels, reliable results were guaranteed.
authors.affiliation: Institute of Food Chemistry, University of Hohenheim , Garbenstrasse 28, 70599 Stuttgart, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Oellig
mesh_terms: D015415:Biomarkers / Q000032:analysis* / Q000737:chemistry; D002855:Chromatography, Thin Layer / Q000379:methods*; D005453:Fluorescence; D005506:Food Contamination / Q000032:analysis; D009281:Naphthalenes / Q000737:chemistry; D015203:Reproducibility of Results; D012277:Ricinoleic Acids / Q000032:analysis* / Q000737:chemistry; D012434:Secale / Q000737:chemistry*; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods
chemical_list: D015415:Biomarkers; D009281:Naphthalenes; D012277:Ricinoleic Acids; C104664:2-naphthoyl chloride; C030521:ricinoleic acid
keywords: HPTLC−FLD; Secale cornutum; high-performance thin-layer chromatography−fluorescence detection; ricinoleic acid; rye; screening