The Van de Berg modification of Ehrlich reagent adds what to the reaction as an accelerator?

The Van de Berg modification of Ehrlich reagent adds what to the reaction as an accelerator?

• A. Added alcohol as an accelerator
• B. Added acid
• C. Added salt
• D. Added sugar

Answer: (A)

The Van de Berg modification introduces an alcohol as a co-solvent to the Ehrlich reagent reaction. The alcohol acts as an accelerator by increasing the solubility of the reactants and the colored product, and by helping extract the chromophore into the solvent. This speeds up the formation of the pink/red color and enhances the intensity, making the test faster and more sensitive for detecting urobilinogen in urine. Adding acid is already part of the reagent system, while salt or sugar don’t promote this color-changing reaction in the same way; the key accelerator in this modification is the alcohol.

The Van de Berg modification introduces an alcohol as a co-solvent to the Ehrlich reagent reaction. The alcohol acts as an accelerator by increasing the solubility of the reactants and the colored product, and by helping extract the chromophore into the solvent. This speeds up the formation of the pink/red color and enhances the intensity, making the test faster and more sensitive for detecting urobilinogen in urine. Adding acid is already part of the reagent system, while salt or sugar don’t promote this color-changing reaction in the same way; the key accelerator in this modification is the alcohol.