Competitive isotopic Method, for the determination of vitamins in Food and bu2081u2082 bu2089

摘要

A method was developed for the determination of isotopic competitive bu2089 Vitamins in foods and bu2081u2082, modifying a radioimmunoassay technique designed for Vitamin bu2089 0.5 ng / ml and for Vitamin bu2081u2082 50 pg / ml. allows Repetitive Results (CV = 4%) and R Eproducibles between Operators (CV = 15%) and Laboratory (CV = 6%).It is a Rapid technique, Easy realization, less costly and specified for these Vitamins, in addition to give comparable results with the official method proposed by AOAC for Soft Drinks: normally consumed by the population, some of them Enriched or Fortified, Bu2089 Vitamin levels were detected in a range of 140 - 280 ng / ml.And Vitamin bu2081u2082 between 1600 - 2000 pg / ml.Claim 1: Employment competitive isotopic method for the determination of vitamins in food bu2081u2082 bu2089 and, according to the technique described below: The Technique for the determination of vitamins bu2089 and bu2081u2082 developed consists in: a) preparation of the sample L To analyze u00edquida: Add 200 ml of calibrators and samples to analyze Conical Glass Tubes.The Conical pipes are used for Phase Separation in the subsequent stages; (b) addition of Radioactive Isotopes and u00b9u00b2u2075i u2075u2077co samples to analyze. ADD 1 ml of the Tracer (Vitamins marked) and dithiothreitol (a reducing Agent) and 30 minute Incubation at room temperature; (c) Alkaline denaturation of Proteins.Add 50 ml of NaOH + KCN to 98.6 Tubes and incubate for 30 minutes; (d) add 1000 ml of microcrystalline Cellulose (Binder) with Continuous homogenization.Cover the tubes to prevent splashing and Evaporation; (e) incubation Binder vitamins and Tracer for 120 minutes with agitation to a temperature of 30; (f) separation of the solid phase by centrifugation; (g) phase Separation by combining Methods of Aspiration And dump the liquid Phase; H) measurement Instruments.Make The Counting of Isotopes in the precipitate with a counter G.