title: A modified ninhydrin micro-assay for determination of total cyanogens in plants.
abstract: Indirect quantification of total cyanogenic compounds (cyanogens) in plants was studied using a novel ninhydrin-based spectrophotometric micromethod. The ninhydrin-cyanide system obeys Beer's law in the range from 20 μg L(-1) to 800 μg L(-1) CN(-) with molar absorptivity ε=1.4×10(5) L mol(-1)cm(-1). Recovery at 100 μg L(-1) CN(-) was 100.5±0.1% and LOD and LOQ were 8 and 22 μg L(-1), respectively. The conditions for ninhydrin reagent preparation were discussed. The extraction and separation solutions, extraction and incubation time, and solvent volume were also investigated for maximum recovery of total cyanogens. 0.1% NaHCO3 was used as an extraction solvent for cyanide formed after enzymatic hydrolysis of cyanogens. The procedure was suitable for samples containing more than 90 mg CN(-)/100 g sample. When cyanogen concentrations were lower, the resulted cyanide was separated by microdiffusion in a Conway cell. Water was used as a hydrolysis medium and a donor solvent, while 2% Na2CO3 as an absorbing solution. Total cyanogen content in plum and almond kernels, as well as apple and flax seeds was determined.
authors.affiliation: Analytical Chemistry Department, University of Chemical Technology and Metallurgy, 8 St. Kl. Ohridski Blvd., 1756 Sofia, Bulgaria. surleva@uctm.edu
authors.forename: Andriana
authors.initials: A
authors.lastname: Surleva
authors.forename: Gabi
authors.initials: G
authors.lastname: Drochioiu
mesh_terms: D019597:Flax / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D027845:Malus / Q000737:chemistry*; D009555:Ninhydrin / Q000737:chemistry; D009570:Nitriles / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D027861:Prunus / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D013053:Spectrophotometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D009570:Nitriles; D010936:Plant Extracts; C011206:cyanogen; D009555:Ninhydrin
keywords: Cyanide quantification; Cyanogens; Hydrolysis; Ninhydrin reagent