Simultaneous Cell Disruption Extraction and Purification Followed by Two-phase Derivatization Procedure for the Determination of Organotin Compounds in Wet Biological Samples by GC–MS

Freeze-dried biological samples used for the determination of organotin compounds (OTCs) involve complicated or tedious pretreatment (e.g., freeze-drying) that may result in loss of analyst or contamination. In the present study, a rapid and accurate method for determination of five kinds of OTCs—monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPhT) and triphenyltin (TPhT) in fresh biota samples—was developed and further compared with freeze-dried tissues. It involved a sample preparation method of simultaneous extraction and purification of OTCs in fresh biological samples, which was developed with ultrasonic cell disruption and primary secondary amine (PSA) adsorption, and followed by two-phase (organic solvent and cell membrane phases) derivatization before the analysis by gas chromatography–mass spectrometry. The extraction efficiency from biota matrices was relatively better with the acetate/acetic acid and tropolone into methanol as extraction agents and primary secondary amine as grease-removing agents. The retention of cell membrane-like materials as well as 25% of ethyl acetate as co-extraction reagents used after centrifugation improved the targeted OTCs’ recoveries. The proposed method, under the optimal condition, has shown satisfactory performance in wet biological samples. The limits of detection obtained were less than 10 ng Sn g −1 ww (wet weight) for all analytes. Spiked recoveries were within the range 89–118% and the relative standard deviations were less than 7% ( n = 5) when quantified by matrix-matched calibration curves. Finally, the applicability of this new method was further verified by comparing the results from wet and freeze-dried oyster tissues collected from two coastal cities in China. Graphical Abstract