Solid phase extraction of organotin compounds in seawater.

Abstract

For the speciation of ultra trace organotin compounds, a technique for separation and preconcentration, such as organic solvent extraction, is useful. However, a solid phase extraction (SPE) is preferable from the viewpoint of environmental pollution. The SPE of comparatively large amounts of organotin compounds in seawater has been developed using a polymer of styrene derivative/metacrylic ester as a solid phase sorbent. The sor-bent (500 mg) was put into a 8 ml reservior. Recovery of organotin was measured by AAS. In pure water containing organotin compounds (TBT, TPT) there was almost 100% recovery in the range of pH 0.25-8.0, while in the 2.45% sodium chloride solution (equivalent to the sodium chloride content in seawater) the recoveries decreased to about 50~60%. This problem was resolved by adding methanol. To prepare sample solutions, methanol was added to be 50%(v/v), in artificial seawater samples containing organotin standard solutions and the pH was adjusted to 0.5 with nitric acid. The water samples were forced through the cartridge at a flow rate of 4.5 - 5.0 ml min-l. Elution was by gravity flow of 10 ml methanol. Recoveries of TPT and TBT were more than 90%, while those of DPT and DBT were about 30 and 60%, respectively. © 1994, The Japan Society for Analytical Chemistry. All rights reserved.