Qualitatively Analysis of Organotin in Plastics from Electrical and Electronic Products by Microwave Digestion-ICP-AES

A microwave digestion-ICP-AES method for qualitative analysis of organotin in plastics from electrical and electronic products was established.The experimental conditions were optimized.The optimized microwave digestion procedure was that the samples were put into the mixture of 5 mL HNO3,1 mL H2O2 and 1 mL HBF4 under 190 ℃ for 30 min.In this condition,most plastic samples could be throughout digested.For the plastics that were difficult to digest,like ABS,the temperature could be rised to 220 ℃ for 60 min.Working condition of the instrument was also optimized,appropriate analysis line that had the less interference to tin was selected.This method had a good linearship between the concentration series of digested organotin and the intensity.Adding dimethyl tin to PVC blank matrix,dioctyl tin to PS blank matrix and triphenyl tin to ABS blank matrix,the average recoveries varied from 88% to 102%,and the relative standard deviations(RSDs)were less than 3%.This method was used to 16 samples,and three of them were proved to be organotin positive.Take translucent PVC plastic and red PVC tube positive samples as an example,the determination results of organotin with the microwave digestion-ICP-AES method were in good agreement with that of GC-MS method.This method showed high practicability,reproducibility and sensitivity.It could satisfy the requirement of qualitatively analysis of organotin in electrical and electronic products.