A simple derivatization reaction with N,N-dimethylformamide dimethyl acetal (DMF-DMA) was developed for the analysis of perfluorocarboxylic acids (PFCA, C4–C12) in solid samples by gas chromatography–mass spectrometry (GC–MS). After extraction with methyl tert-butyl ether (MTBE), the samples are mixed with derivatizing agent and injected into GC. The derivatization reaction takes place in injection block forming corresponding N,N,N′,N′-tetramethyl diamines. The method provides excellent separation of nine PFCA (C4–C12) in 15 min and is characterized by good precision (max. RSD = 6.21% for 10 ng/mL, n = 6), linearity and detection limits in the range of 0.15–0.38 ng/mL. The main aim of the study was to develop a quick and easy GC–MS screening for PFCA. The method was successfully applied for sewage sludge, textiles and dental flosses. To confirm the laboratory evaluation, two samples were measured by an external laboratory using LC–MS/MS and showed comparable results. The proposed method is very promising, taking into account its simplicity, mild conditions and application of cost-effective GC–MS system. Additionally, a comparison with two other derivatization methods for PFCA: reaction with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and benzyl bromide is presented.

中文翻译：

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在 GC-MS 分析之前使用 N,N-二甲基甲酰胺二甲基缩醛衍生化全氟羧酸

开发了与 N,N-二甲基甲酰胺二甲基乙缩醛 (DMF-DMA) 的简单衍生反应，用于通过气相色谱-质谱 (GC-MS) 分析固体样品中的全氟羧酸 (PFCA, C4-C12)。用甲基叔丁基醚 (MTBE) 萃取后，将样品与衍生剂混合并注入 GC。衍生反应发生在注射块中，形成相应的 N,N,N',N'-四甲基二胺。该方法可在 15 分钟内实现 9 种 PFCA (C4–C12) 的出色分离，并且具有良好的精密度（10 ng/mL 的最大 RSD = 6.21%，n = 6）、线性和检测限范围为 0.15– 0.38 纳克/毫升。该研究的主要目的是开发一种快速简便的 GC-MS PFCA 筛查方法。该方法已成功应用于污水污泥、纺织品和牙线。为确认实验室评估，外部实验室使用 LC-MS/MS 测量了两个样品，并显示了可比较的结果。考虑到它的简单性、温和的条件和具有成本效益的 GC-MS 系统的应用，所提出的方法非常有前途。此外，还比较了 PFCA 的其他两种衍生方法：与 N,O-双（三甲基甲硅烷基）三氟乙酰胺 (BSTFA) 和苄基溴的反应。