Análisis de Colorantes Alimentarios por Espectrofotometría

Identificación de colores alimentarios artificiales por sus espectros de absorción

Colorimetry Intermediate (High School) 60 min ~$8,00

Objetivo

Determinar la identidad y concentración de colorantes alimentarios artificiales en bebidas comerciales midiendo sus espectros de absorción.

Antecedentes

Artificial food dyes have characteristic absorption spectra that serve as fingerprints for identification. FD&C Red No. 40 absorbs maximally at 504 nm, Blue No. 1 at 630 nm, and Yellow No. 5 at 428 nm. By scanning the absorption spectrum of a commercial beverage and comparing peak wavelengths with known dye spectra, students can identify which dyes are present and estimate their concentrations.

Advertencias de seguridad

  • Food dyes can stain clothing
  • Do not drink any samples after use in the lab
  • Handle cuvettes by the frosted sides only

EPP requerido

goggles lab_coat

Materiales

  • Standard food dye solutions (50 mL each)
    Red 40, Blue 1, Yellow 5 (0.01%)
  • Commercial beverages (50 mL each)
    2–3 colored drinks
  • Distilled water (200 mL)
    For dilutions and blank

Equipamiento

UV-Vis spectrophotometer (or colorimeter with multiple filters) Cuvettes (quartz or plastic) Pipettes Volumetric flasks (25 mL, 4 total)

Procedimiento

1

If using a spectrophotometer, scan each standard dye solution from 400 to 700 nm to identify the λmax (wavelength of maximum absorbance).

10 min
2

Record the λmax for each standard: Red 40 (≈504 nm), Blue 1 (≈630 nm), Yellow 5 (≈428 nm).

5 min
3

Dilute commercial beverage samples if too concentrated (absorbance should be below 1.0). Record all dilution factors.

10 min
4

Scan each beverage sample from 400 to 700 nm. Record the absorption spectrum.

15 min
5

Compare the beverage absorption peaks with the standard dye λmax values to identify which dyes are present.

10 min
6

If a calibration curve was prepared for a specific dye, calculate the dye concentration in each beverage (accounting for dilution).

10 min

Resultados esperados

Each beverage should show absorption peaks matching one or more standard food dyes. Green drinks typically contain both Blue 1 and Yellow 5. Orange drinks often contain Red 40 and Yellow 5.

Limpieza

Pour dilute dye solutions down the drain with running water. Rinse cuvettes immediately to prevent staining.

Detalles

Categoría
Colorimetry
Dificultad
Intermediate (High School)
Duración
60 min
Costo estimado
$8,00
Pasos
6
Materiales
3

Más experimentos

Análisis Espectrofotométrico de una Mezcla 75 min Determinación Colorimétrica de Fosfato 90 min Determinación Colorimétrica de Glucosa 60 min Determinación de Hierro en Agua 75 min Determinación Espectrofotométrica de Aspirina 75 min Ensayo Colorimétrico de Proteínas (Método Bradford) 60 min Verificación de la Ley de Beer-Lambert 60 min

Frequently Asked Questions

What is the objective of Análisis de Colorantes Alimentarios por Espectrofotometría?
Determinar la identidad y concentración de colorantes alimentarios artificiales en bebidas comerciales midiendo sus espectros de absorción.
How difficult is Análisis de Colorantes Alimentarios por Espectrofotometría?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for Análisis de Colorantes Alimentarios por Espectrofotometría?
Key safety precautions include: Food dyes can stain clothing; Do not drink any samples after use in the lab; Handle cuvettes by the frosted sides only.
What materials are needed for Análisis de Colorantes Alimentarios por Espectrofotometría?
The main materials required are: Standard food dye solutions, Commercial beverages, Distilled water.
What results should I expect from Análisis de Colorantes Alimentarios por Espectrofotometría?
Each beverage should show absorption peaks matching one or more standard food dyes. Green drinks typically contain both Blue 1 and Yellow 5. Orange drinks often contain Red 40 and Yellow 5.