Butyl- and Phenyl-tin Determinations in Mussel

Following the above-mentioned certification, it was considered of paramount importance to improve the quality control of various analytical steps such as 

Corrections for moisture were performed by drying a separate mussel sub- 

Beside the preparation of pure calibrants for the purpose of certification, independent studies were carried out to investigate possible sources of error existing at the extraction and derivatization steps. The study on derivatization demonstrated that the yields obtained by Grignard reactions were generally 

Stationary phase loaded with 10% SP-2100 the column was electrically heated with a Ni-Cr wire). Final detection was by ICP-MS. Extraction recoveries were calculated by spiking the material (previously wetted with methanol and mixed with spiking solution) at three levels the recoveries ranged from 97% (TBT) and 98% (MBT) to 112% (DBT). Calibration was by standard additions, using MBTCI3, DBTCI2 and TBTCl in methanol. 

Second method 0.5 g sample was digested with a 5 mL mixture of 10% HBr and 60% methanol and stirred for 1 h. Extraction was carried out by addition of 10 mL of 0.05% tropolone in methanol, stirring for 30 min and then centrifuging for 5 min. The organic layer was derivatized with 0.2 mL of 4% NaBH4 solution. Clean-up was performed with Florisil followed by elution with hexane. Separation was by GC (column of 5 m length, 0.32 mm internal diameter, DB-1 as stationary phase He as carrier gas at 5 mL min injector temperature of 250 °C column temperature ranging from 80 to 250 °C). Detection was by FPD (detector temperature of 350°C). 

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