Disaccharide analysis of Mono Q peak III. Mono Q peak III was treated with nitrous acid and chondroitin AC II–lyase to degrade HS, C4S, and C6S as shown in Figure 2. The remaining DS was digested with chondroitin ABC–lyase, and the resulting products were chromatographed on a Spherisorb-SAX column (A). The other chromatograms represent porcine mucosal DS digested with chondroitin ABC–lyase (B), a mixture of Δ^4,5-unsaturated disaccharide standards (C), and a blank run (D). The numbered peaks indicate the elution positions of the following disaccharide standards: 1, Δ^4,5UA→GalNAc; 2, Δ^4,5UA→GalNAc6SO₃; 3, Δ^4,5UA→GalNAc4SO₃; 4, Δ^4,5UA2SO₃→GalNAc4SO₃; and x, unidentified peak.