Method for determination of the delta-d values ​​of stable isotopes not exchangeable hydrogen in the methyl group of ethanol by instrumental technique IRMS

摘要

A process for determining the origin of a food product containing alcohol, comprising: providing a sample of the food product containing alcohol; neutralize volatile acids provided lamuestra; degrading carbonyl compounds: aldehydes and ketones in the provided sample; extracting unamuestra ethanol sample provided; provide enzyme ethanol dehydrogenase and acetaldehyde dehydrogenase, and deoxidación-reduction coenzyme NAD + to convert ethanol in the sample from ethanol to acetic acid; remove acetic acid, wherein the extraction step acetic acid includes at least one of following losprocesos: distillation in the presence of superheated steam or vacuum distillation, to produce a solution of the acetate salt extracted acetic acid by neutralizing the acid acéticoextraído until the pH of the solution reaches 8.1; concentrating the solution of the acetate salt produced by vacuum distillation until the solution reaches acetate pay off a syrup, wherein the distillate product is discarded; cooling concentrated acetate salt the Remedy; remove impurities from the concentrated and cooled acetate salt by adding a solventeorgánico and mix the solution in an ultrasonic water bath solution, wherein the organic solvent dissolves lasimpurezas; discard the organic solvent contains dissolved impurities using a separatory funnel, to obtain the salt dry acetate to constant mass of the purified concentrated solution of deacetato salt, to measure the isotopic composition, ie, the isotopic ratio relative deuterium and hydrogen dry deacetato salt , calculate the value of dD by measuring the isotopic composition; ycomparar the computed dD values ​​of dD associated with a food product origenconocido value.