离子液提取与顶空气-质联用测定PU革中DMF方法研究

Study on Detection Method of N,N-Dimethyl Formamide in PU Synthetic Leather

建立了一种对聚氨酯合成革中残留N,N-二甲基甲酰胺提取及检测的新方法,对聚氨酯合成革样品前处理离子液超声提取与顶空气相色谱-质谱条件进行研究.结果表明,最佳样品前处理工艺：提取溶剂为N-正丁基-N-甲基咪唑四氟硼酸盐离子液、溶剂用量为20 mL/g、超声提取温度控制75℃、提取时间1h;最佳气相色谱-质谱条件：顶空加热温度为135℃,平衡时间60 min,顶空基体量1 mL,柱温：50℃保持3 min,然后以12℃/min速度升至200℃,保持4 min.进样口温度200℃;色谱-质谱接口温度250℃.电离方式：EI.该分析方法线性相关系数R2=0.9992;平均回收率97％～100％;标准偏差在3.45％～4.84％之间;检出限量10mg/kg,适用于聚氨酯合成革的DMF测定.

A new detection and extraction method of N, N-dimethyl formamide in PU synthetic leather was established. The sample pretreatment ionic liquid ultrasonic extraction conditions and head-space gas chromatography-mass spectrometry conditions of PU synthetic leather were studied. The results showed that, the optimal sample preparation conditions were： extraction solvent was N-butyl-N-methyl imidazole tetrafluoroborate ionic liquid; the optimal dosage of solvent was 20ml/g; the optimal ultrasonic extraction tem- perature was 75℃ for one hour. The optimal conditions of gas chromatography-mass spectrometry were： head -space heating temperature was 135℃; balance time 60rain, head-space matrix volume lml, column HP- 5MS; Column temperature： 50℃ keep 3rain, then at 12℃/min speed up to 200℃, keep 4min; sampling mouth temperature 200℃, gas chromatography-mass spectrometry interface temperature 250℃, Ionization methods EI. These methods procured good linear correlation R2 =0. 9992. The average recovery rate was 97 %- 100 %. The standard deviation was between 3.45 % - 4.84 % and the detection limit was 10ppm. This method is suitable for the detection of DMF residues in PU synthetic leather.