Provide the structure of L-arginine at pH 2.0.

What makes the backbone of DNA?

A) Nucleic acids
B) Phosphoric acid
C) Deoxyribose sugar
D) Phosphoric acid and deoxyribose sugar

What does a blank sample determine?

A) The air level of organic contaminants
B) The air level of organic pollutants
C) The background level of arson containers
D) The background level of organic compounds

Deduce the identity of the following compound from the ¹H NMR data given.
C₇H₁₂O₄: δ 1.3 (6H, triplet), 3.4 (2H, singlet), 4.2 (4H, quartet) (ppm)