固相微萃取-气相色谱-质谱法鉴定火场残留物中油漆稀释剂

Determination of Paint Thinner in Fire Debris by GC-MS with SPME

对采用固相微萃取-气相色谱-质谱法从火场残留物样品中鉴定油漆稀释剂进行了研究。将火场残留物样品放入密闭的金属容器或塑料袋中,置于80℃烘箱加热20-30 min,在固相微萃取装置中用100μm聚二甲基硅氧烷纤维通过针头将密闭容器中的油漆稀释剂成分（此时已成气态）吸附,吸附时间为5-10 min,然后将纤维插入气相色谱进样口中解析进样,解析时间为2 min,按照预定的条件进行气相色谱-质谱分析。对气相色谱-质谱谱图上所得的峰进行分析,并与同条件下获得的油漆稀释剂试验样品气相色谱-质谱谱图进行比较,从而对油漆稀释剂作出定性鉴定。

The fire debris sample was placed in a metal vessel or plastic bag,sealed tightly and heated at 80 ℃ in an oven for 20-30 min,to change the paint thineer into gaseous state,which was adsorbed on the 100 μm polydimethylsiloxane（PDMS） fibre through a springe needle stuck into the vessel or bag.Five to 10 min were taken for the adsorption,and the springe needle was taken out and transferred into the sample inlet of the GC instrument.It took 2 min for desorption of the paint thineer from the PDMS fibre,which was then analyzed by GC-MS according the prescribed procedure.Constituents of the thinner were identified by comparing the peaks in the spectrum of sample with those in the spectrum of known compounds in simulated samples.