Decomposition of dithionite(S2O42-).was studied by chromatography on an anion-exchange column eluted with 20mM tri-sodium 1, 3, 6-napthalenetrisulfonate in 90 vol%H2O/10

vol%CH3CNwith ultraviolet detection at 280 nm. A solution of sodium dithionite stored for 34 days in the absence of air gave five peaks identified asSO32-,SO42-,S2O32-,S2O42-andS2Os2-All the peaks had a negative absorbance. Explain why.

Short Answer

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The explanation to the above question is:

Our analytic anions don’t absorb strongly at 280 nm, therefore the peaks have a negative absorbance.

Step by step solution

01

Case of indirect detection

This is a case of indirect detection where the eluent contains trisodium 1, 3, 6-napthalenetrisulfonate with ultraviolet detection at 280 nm, meaning it absorbs at 280 nm.

02

Explanation of peaks having negative absorbance

Charge balance determines that when anions emerge from the column – less trisodium 1, 3, 6-napthalenetrisulfonate should be emerging.

  • Our analyte anions don’t absorb strongly at 280 nm, therefore the peaks have a negative absorbance.

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