气相色谱法测定聚苯乙烯中残留苯乙烯单体含量

Determination of residual St monomers in PS by gas chromatography

依据ISO 2561:2012(E)测试了聚苯乙烯(PS)中残留苯乙烯(St)单体的含量,以N,N-二甲基甲酰胺作提取剂,分析了柱温、载气流速、进样量、分流比对气相色谱分离效果的影响。在同样条件下,与峰面积法校准曲线相比,内标法校准曲线的线性相关性更高,达0.999 98。ISO 2561:2012(E)规定建立校准曲线至少需4个校准浓度的溶液,为多点法;而GB/T 16867—1997规定建立校准曲线只需1个校准浓度,为单点法。因此,与采用GB/T 16867—1997测得的结果相比,依据ISO 2561:2012(E)测得的结果准确度更高。采用ISO 2561:2012(E)与ISO 2561:2006(E)测定了4种国内市售PS中残留St单体的含量,发现在现有4种PS中,依据ISO 2561:2012(E)测出的残留St单体浓度略有降低。

The residual styrene(St)monomer in polystyrene(PS)which was extracted by N,Ndimethylformamide(DMF)was analyzed via ISO 2561:2012(E)standard.The factors contributing to the results of gas chromatograph such as column temperature,carrier gas flow velocity,amount of sample injection and split ratio were discussed.The calibration curve of internal standard method has higher linear correlation of 0.999 98 than that of the peak area method.The multipoint method requires solutions in four calibration concentrations in establishing calibration curve according to ISO 2561:2012(E),while single point methods requires only one calibration concentration according to GB/T 16867-1997,therefore,the testing results from ISO 2561:2012(E)are more accurate than those from GB/T 16867-1997.The residual St in 4 market available PS were tested on the basis of ISO 2561:2012(E)与ISO 2561:2006(E)respectively.The results indicate that the concentrations of St monomer in polymers are slightly lower according to ISO 2561:2012.