In this study, freestanding fully porous polyimide (FFPP) membranes were prepared in batches by the scraping technique and vapor-induced phase separation (VIPS) and used for thin film microextraction (FFPP-TFME). When water vapor was applied simultaneously during scraping, the resulting membrane surface was highly porous, in contrast to the dense and smooth surface obtained without vapor. The micro/nanocomposite pore structure was revealed by scanning electron microscopy and nitrogen adsorption–desorption. The diameters of the micropores, nanopores and fibrous polyimide (PI) nanofibers were 0.5–1.5 μm, ca. 30 nm and ca. 250 nm, respectively. The extraction performance of the FFPP-TFME method was evaluated with organochlorine pesticides (OCPs) as model analytes in water. The extracted OCPs were desorbed in acetone and then quantified by gas chromatography–mass spectrometry. The effects of extraction time, ionic strength, desorption solvent, desorption volume and desorption time were investigated. Under the optimized conditions, the limits of detection (LODs) for eight OCPs (4.4–83 ng L⁻¹), linear ranges (0.05–50 μg L⁻¹), correlation coefficients (0.997–0.999), intrabatch relative standard derivations (RSDs, 0.88–9.20%) and interbatch RSDs (6.35–13.5%) were obtained. The method was also successfully applied to the analysis of environmental water samples, and the relative recoveries of all real water samples were 73.6–116.4%. These results show that the FFPP-TFME method is a simple, efficient and environmentally friendly method for the pretreatment of trace organic pollutants in water samples.

在这项研究中，通过刮擦技术和气相诱导相分离（VIPS）分批制备了独立式全多孔聚酰亚胺（FFPP）膜，并用于薄膜微萃取（FFPP-TFME）。当在刮擦期间同时施加水蒸气时，与没有蒸气时获得的致密和光滑的表面相反，所得的膜表面是高度多孔的。显微/纳米复合材料的孔结构通过扫描电子显微镜和氮吸附-解吸揭示。微孔，纳米孔和聚酰亚胺纤维（PI）纳米纤维的直径约为0.5–1.5μm。30 nm左右 分别为250 nm。使用有机氯农药（OCP）作为水中的模型分析物评估了FFPP-TFME方法的萃取性能。提取的OCP在丙酮中解吸，然后通过气相色谱-质谱法进行定量。研究了萃取时间，离子强度，脱附溶剂，脱附量和脱附时间的影响。在最佳条件下，八个OCP（4.4–83 ng L^-1），线性范围（0.05–50μgL ^-1），相关系数（0.997–0.999），批内相对标准偏差（RSD，0.88–9.20％）和批间RSD（6.35–13.5％）。该方法还成功地用于环境水样的分析，所有真实水样的相对回收率均为73.6–116.4％。这些结果表明，FFPP-TFME方法是一种简单，高效且环境友好的方法，可以对水样中的痕量有机污染物进行预处理。