微孔有机聚合物固相微萃取纤维的制备及在有机氯农药检测中的应用

利用1,3,6,8-四(4-醛基)芘和三聚氰胺为单体合成微孔有机聚合物(MOP),并将其固定在不锈钢丝上,制备成固相微萃取纤维涂层。将其用于顶空固相微萃取(HS-SPME),结合气相色谱-电子捕获检测手段,建立了对大米中有机氯农药的在线检测方法。实验考察了4种实验参数对富集能力的影响,得到了最优的实验条件:萃取温度80℃、萃取时间25 min、NaCl质量浓度200 g/L、解吸时间6 min。在此实验条件下,对有机氯农药的富集倍数达到115~318倍。方法在0.05~50μg/kg范围内具有良好的线性关系,检出限为2.4~11.3 ng/kg。同一纤维及不同纤维富集后测定结果的相对标准偏差范围分别为1.3%~13.1%和2.3%~13.6%。该方法简单、快速,可以实现对实际样品中有机氯农药的痕量分析。

Preparation of microporous organic polymer-based solid phase microextraction fiber and application to the determination of organochlorine pesticides

In the present work, a microporous organic polymer (MOP) was prepared with 1,3,6,8-tetrakis(p-formylphenyl)pyrene and melamine as monomers. The MOP material was adhered on a stainless steel fiber for headspace solid phase microextraction (HS-SPME). By combining with gas chromatography-electron capture detection, an online method was developed for the determination of organochlorine pesticides (OCPs) in rice samples. Four experimental parameters affecting the preconcentration efficiency were investigated in details. Under the optimum experimental conditions, extraction temperature of 80℃, extraction time of 25 min, NaCl mass concentration of 200 g/L, and desorption time of 6 min, high enrichment factors of 115-318 were achieved. The MOP-based fiber exhibited good linearity for OCPs in the range of 0.05-50 μg/kg. The detection limits ranged from 2.4 ng/kg to 11.3 ng/kg with relative standard deviations of 1.3%-13.1% for the same fiber and 2.3%-13.6% for different fibers. The developed method was proved to be simple and rapid and to be applied to the determination of trace amount of OCPs in rice samples.