Abstract: In order to solve the problem that the quantification limit of organotin in the second type of toy materials is difficult to reach，and to increase the types of migrating organotin compounds (OTCs) detected in toys，a gas chromatography-tandem mass spectrometry (GC-MS/MS) detection method capable of simultaneously determining 20 migrating OTCs in toys was established，by taking the second type of toy materials as the research object and optimizing the experimental conditions． After migration from simulated gastric juice (HCl) followed by derivatization using the derivatizing agent (sodium tetraethylborate)，the OTCs were analyzed by multiple reaciton monitoring mode (MRM)，during which，migration conditions，derivatization steps as well as operating parameters of GC-MS/MS were optimized． The experimental result shows that the 20 kinds of OTCs display good linear relationship in the concentration range from 0. 005 to 0. 200 mg/L with the linear correlation coefficients of 0. 9963 ～ 0. 9999． The spiked recoveries of OTCs in samples are in the range of 80. 6% ～117. 2% with relative standard deviations less than 5% (n = 6) and their detection limits are as low as 0. 019 ～ 3. 196 μg/kg with the limit of quantifications between 0. 065 and 10. 652μg/kg． Compared with GC-MS，the most commonly employed method for OTCs detection in toys，the newly established method can separate 20 different kinds of OTCs within 20min at one time，indicating the advantages of strong selectivity，accurate quantification，high sensitivity with a very low detection limit and quantitation limit，dissolving the problem that the quantitation limit of OTCs for the second type of toy materials was difficult to be achieved． Furthermore，this method also extends the detection limitation of OTCs types in toys to 20 types from the original 11 types given in the EU standard． The developed method was proved to be comprehensive，efficient，reliable and sensitive for fast determination of OTCs in toys．

Key words: toys, organotin migration, GC-MS/MS, detection