sources of organic contaminants found in water (may include dioxins, insecticides, pesticides, oil spills)
• the application of high performance liquid chromatography (HPLC) including the use of a calibration curve and
retention time to determine the concentration of a soluble organic compound in a water sample (excluding
details of instrument).
Organic pollutants can come from different sources, such as:
These are organic pollutants that are toxic and the molecules take a long time to break down to less harmful products.
1. DDT -DDT stands for dichlorodiphenyltrichloroethane.
DDT was used as a pesticide.
DDT was banned in 1972 in the USA and in 1987 in Australia.
DDT remains in the environment for a long time. It bio-accumulates in food chains- meaning animals at the top of the food chain get the highest doses.
2. Dioxins- these are chlorinated hydrocarbons that contain 2 oxygens positioned in the middle of the molecule.
Dioxins are highly toxic.
Dioxins are released from human activities such as incinerating and fuel combustion.
Structure of 2,3,7,8-tetrachlorodibenzo[b,e][1,4]dioxine
Diagram courtesy of By Emeldir (talk) - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=32189984
3. Oil Spills
•Oil spills contribute to organic contaminants getting into waterways.
•Oil sits on top of water due to its non-polarity.
•Oil is collected with booms (physical barriers) and treated with dispersants (work like a detergent)- which break up the oil.
Oil spills cover animals and affect their insulation, if ingested or inhaled it is toxic, damages plants and can disrupt food chains.
Structure of DDT courtesy of By Leyo - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9100404
Concentrations of DDT in an estuary on the South Shore of Long Island, DDT moves through food chains in patterns similar to those of certain fallout isotopes, concentrating in the carnivores and causing serious damage to those populations
Image courtesy of By ENERGY.GOV (HD.16.090) [Public domain], via Wikimedia Commons
Oil spill photo courtesy of By U.S. Fish and Wildlife Service - http://www.public-domain-image.com/public-domain-images-pictures-free-stock-photos/transportation-vehicles-public-domain-images-pictures/ships-boats-public-domain-images-pictures/ship-werck-oil-spills-aerial-view.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=24919395