A qualitative and semi-quantitative chemical test that measures the level and/or identifies the pattern of mucopolysaccharides (MPS), also known as glycosaminoglycans (GAGs), in a urine sample. Mucopolysaccharides are long chains of sugars that play structural roles in connective tissue. In a group of rare genetic disorders called mucopolysaccharidoses, a deficiency of certain enzymes leads to the accumulation of these substances in tissues and their excretion in abnormal amounts in the urine. This test is used as a preliminary screening test for these disorders.