Speciation Analysis Of Organotin Compounds Using Solid Phase Microextraction-Supercrical Fluid Extraction-GC/MS

On the basis of reviewing organotin pollution and progress of its determination methods in China and abroad, a new SPME and SFE samples pretreatment method has been developed. Then, the samples were determined by GC/MS. The contents of this dissertation include:1 Determination of six different species of organotins by GC/MS. HP-5 chromatograpy column was selected. The initial temperature was set at 50℃and maintained for 4 min, then rised to 270℃at 50℃/min and maintained for 7 min. The carrier gas was Helium, and the electron impact (EI) ionization mode was employed with electron energy of 70 eV. The determination of organotins in stimulant samples indicated the method could applied for practical samples.2 The conditions for SPME and SFE pre-treatment have been optimized. Organotins were derivatized in situ with sodium tetraethylborate and adsororbed on a poly (dimethysiloxane/ divinyl benzene) (PDMS/DVB) (65μm)-coated fused silica fiber. Organotins in water were extracted at pH4.0 and derivatized simultaneously by NaBEt₄ at the ratio of 2 %(w/v) at 50℃for 30 min and desorption in the spliteless injection port of the GC at 260℃for 1 min. The SFE procedures for extraction of organotins in seafood were at 30MPa and 45℃for 15 min with No.3 chelator (NH₄DDC). The flow rate for supercritical CO₂ was 1.2 mL/min, and 5% methanol was added to improve the extraction. The SPME-SFE-GC-MS method for determination of organotin in seafood sample has been developed on the basis of the above investigation;3 The occurrence of organotins in surface water of Haihe, entrance of Haihe to Bohai, sewage farm and tap water factory in Tianjin were determined by HS-SPME-GC-MS. The detection limit of the method was to ng Sn /L. The recoveries were between 80.2～102%. The results indicated that the simple and rapid SPME-GC-MS method could be applied for determination of organotins in environment. ?4 Analytical procedures for GC-MS determination of organotins in part of seafood samples from Bohai Bay were developed in the laboratory with SPME and SFE pre-treatment. The new method met the requirement for environmental analysis very well. The results showed that the most of aquatic organisms were polluted by organotin. TBT, DBT, MBT, MPT, TPT were found in some of determined samples, and TBT was found for all the tested samples. The government needs to take some measures to deal with the pollution of organotins.