Carbohydrates are a class of aldehyde or ketone derivatives of polyhydric alcohols, particularly the pentahydric and hexahydric alcohols, i.e., polyhydroxyaldehydes or polyhydroxyketones containing only carbon, oxygen, and hydrogen. Usually the ratio of hydrogen to oxygen is 2:1. Thus, they are so named because the hydrogen and oxygen are usually in the proportion to form water. These chemical compounds are the primary biological means of storing or consuming energy, other forms being fat and protein and are naturally produced by both plants and animals. Carbohydrate is also a generic biochemical name for sugar containing molecules including single sugars (monosaccharides) like glucose and galactose, but also polysaccharides (complex carbohydrates) like starch (poly-glucose), cellulose (plant fiber material, which is also a poly-glucose with a different chemical bond structure linking glucose units than those found in starch/glycogen and enzymatically indigestible by humans), chitin (hard shells of insects), and the more complex carbohydrate components part of lipids and proteins. Carbohydrates are the sugars and starches found in breads, cereals, fruits, and vegetables, which, during digestion, are changed into a simple sugar, glucose. Glucose is stored in the liver as glycogen until cells need it for energy. Carbohydrates include simple carbohydrates (sugar, fruit) and complex carbohydrates (vegetables, starches). Carbohydrates consist of starch, sugars and some related substances such as sugar alcohols (eg. sorbitol) and organic acids (e.g., citric acid).


  • glucose (dextrose)
    Glucose (dextrose)is a simple sugar used in foods and drinks. It is most often measured using HPLC and GC/MS.
  • lactose
    Lactose (milk sugar) is a disaccharide found in milk and used pharmaceutical tablets. It is most often measured using HPLC and GC/MS.