Glycosaminoglycans were extracted from brain, kidney, liver, lung and spleen or from isolated liver lysosomes (tritosomes) of 12-month-old WT or ARSK-deficient mice. The amount of heparan sulfate (HS) was determined in the indicated tissues (A) and tritosomes (B) by LC/MS after glycan reductive isotope labeling (GRIL). Similarly, the amount of chondroitin sulfate (CS) was determined in the various tissues (C) and liver lysosomes (D) (n = 3 per genotype, values represent mean ± SEM, *P < 0.05, **P < 0.01). (E,F) The composition of HS- and CS-derived disaccharides were evaluated regarding acetylation (N-Ac) and sulfation by GRIL-LC-MS indicating a minor increase in 2-O-sulfated HS disaccharides.