BATCH OPERATION OF SOLID-PHASE EXTRACTION FOR SEPARATION AND CONCENTRATION OF ORGANOTIN COMPOUNDS IN SEAWATER

For the speciation of ultra trace organotin compounds, a batch techniq ue for solid phase extraction (SPE) has been developed using a polymer of styrene derivative/metacrylic ester (Excel-pack SPE-GLF, Yokogawa Analytical Systems Inc., Japan) as a solid phase sorbent. The recovery of organotin compounds was measured by miceller liquid chromatography /inductively coupled plasma mass spectrometry (MLC/ICP-MS). The mobile phase was 40 mM tris(hydroxymethyl) amino methane dodecyle sulfate, 7 5 mM ammonium nitrate, 3%v/v acetic acid, and 20%v/v ethanol solution. The procedure was as follows. Add 0.5 g SPE sorbent suspended in 10 m l methanol into seawater samples (0 similar to 31) which was previousl y acidified to pH 2 with hydrochloric acid. After shaking for 5 min in a separating funnel, pour the solution with sorbent into a 8 ml reser voir at a now rate of ca. 50 ml min(-1). Wash the sorbent with 20 mi o f 10%v/v methanol. flute organotin compounds by gravity flow of 12 mi methanol. Evaporate the methanol effluent to 1.0 g at 30 similar to 35 degrees C under argon gas flow. Add 1.0 g of ultra pure water. Inject 100 mu l of the solution into the MLC/ICP-MS. The recoveries of TPT a nd TBT were almost 100%, while those of DPT and DBT were lower. The ba tch technique was very rapid taking only ca. 20 min for the SPE of 100 0 ml of seawater. The limit of detection (LOD, 3 sigma) of SPE/MLC/ICP -MS was TBT: 5 ng 1(-1) and TPT: 7 ng 1(-1), respectively, when using 1000 ml of seawater. It was also possible to perform the analysis for an effluent that was concentrated to 0.25 ml and the same volume of ul tra pure water was added. Then 100 mu l of the solution was injected t o MLC/ICP-MS. Consequently, the LOD for this case will be much lower. The enrichment factor was 10(3) similar to 10(4). The cartridge techni que of SPE was also comparatively studied.