Tributyltin Chloride in Water: Solid Phase Extraction, Capillary GC Separation and EC Detection

A new procedure for determining trace levels of tributyltin chloride (Bu3SnCl) present in seawater, without resorting to derivatization, has been developed. The stepwise approach involves: [1] solid phase extraction of Bu3SnCl from 100 ml of water using 100 mg of C-18 bonded porous silica; [2] elution with HCl treated ethyl acetate to collect l of the eluate; [3] on-column injection of l of the eluate and separation on a 15 m DB-5 fused silica capillary column; and [4] detection of pg quantities of Bu3SnCl by electron capture. All steps are amenable to automation allowing for low cost determinations of Bu3SnCl and possibly other organotin compounds. Background and stability problems with both bonded porous and fused silica are described using test data from contrived and harbor water samples.