二次热解吸-气相色谱-质谱法测定聚乳酸线材用于增材制造时产生的有机挥发物  

Determination of Volatile Organic Compounds Produced from Polylactic Acid Wire Used for Additive Manufacturing by Secondary Thermal Desorption-Gas Chromatography-Mass Spectrometry

作　　者：陈作王 徐玮辰 CHEN Zuowang;XU Weichen(Wuxi Product Quality Supervision and Inspection Institute,Wuxi 214000,China)

机构地区：[1]无锡市产品质量监督检验院,无锡214000

出　　处：《理化检验（化学分册）》2021年第3期235-240,共6页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：2018年度江苏省重点研发计划(产业前瞻与共性关键技术)项目(BE2018010)。

摘　　要：将聚乳酸(PLA)线材在增材制造时产生的有机挥发物(VOCs)收集在自制的气体收集瓶中,并在20℃下稳定10min,在经活性炭过滤好的空气的作用下,用TenaX-TA吸附管采集收集瓶中气体20min,采集的气体经二次热解吸后,以100∶1的分流比进入气相色谱,用DB-5MS色谱柱在程序升温条件下分离,进入质谱检测器测定其中主要的9种VOCs(包括苯、甲苯、苯乙烯、乙苯、乙酸丁酯、邻二甲苯、间二甲苯、对二甲苯和正十一烷)含量。在优化的条件下,9种VOCs的保留时间为5.30~23.63min。结果显示:9种VOCs的质量分别在40~4000ng(间二甲苯+对二甲苯)和20~2000ng(其他7种组分)内与其对应的峰面积呈线性关系,检出限(3S/N)为1.1~2.5μg·kg^(-1);对实际样品进行3个浓度水平的加标回收试验,所得回收率为91.2%~103%,测定值的相对标准偏差(RSD,n=6)为2.0%~8.5%;用此方法分析了6种样品,9种组分均有不同程度检出,总VOCs(TVOCs)含量的RSD(n=11)小于10%。The volatile organic compounds(VOCs)produced from additive manufacturing with polylactic acid wire were collected in the self-made gas collection bottle and stabilized at 20℃for 10 min.The gas in the bottle was collected with TenaX-TA adsorption tube for 20 min with the aid of air pre-filtered by activated carbon.After secondary thermal desorption,the collected gas was introduced into gas chromatography at a split ratio of 100∶1,to get it separated by DB-5 MS chromatographic column under programmed temperature condition.The contents of nine major VOCs(including benzene,toluene,styrene,ethylbenzene,butyl acetate,o-xylene,m-xylene,p-xylene and n-undecane)obtained were analyzed by mass spectrometry.Under the optimized conditions,the retention times of 9 VOCs were found in the range of 5.30-23.63 min,and the results showed that linearity relationships between masses of nine VOCs and their corresponding peak areas were kept in the ranges of 40-4000 ng(for the sum of mxylene and p-xylene)and 20-2000 ng(for the other 7 components),with detection limits(3 S/N)in the range of 1.1-2.5μg·kg^(-1).The spiked recovery test was made on the actual sample at the 3 concentration levels,giving recoveries in the range of 91.2%-103%,and RSDs(n=6)of measured values were ranged from 2.0%to 8.5%.Six samples were analyzed by this method,and nine components were detected to different degrees,with RSDs(n=11)of TVOCs content less than 10%.

关 键 词：二次热解吸 气相色谱-质谱法 有机挥发物 聚乳酸线材 增材制造 

分 类 号：O657.63[理学—分析化学]