The Russian-Italian biochemist Mikhail Semyonovich Tsvet (or Tswett) (1872–1919) coined the term “chromatography” and published the first paper on the method in 1903. The term comes from the Greek words chroma, meaning “color,” and graphein, meaning “writing or drawing.” Chromatography has many applications in biology. For example, it is used to separate and identify amino acids, carbohydrates, fatty acids, and other natural substances. Environmental testing laboratories use chromatography to identify trace quantities of contaminants such as PCBs in waste oil and pesticides such as DDT in ground water. It is also used to test drinking water and test air quality. Pharmaceutical companies use chromatography to prepare quantities of extremely pure materials.