Cotton is a natural material with good mechanical and chemical properties. It presents a hydrophilic surface that must be modified by the introduction of appropriate groups, if semi-polar or non-polar analytes are intended to be isolated from an aqueous matrix. In this article, cotton is modified with β-cyclodextrins, which presents a hydrophobic cavity where target molecules can be hosted. The cavity size restricts the access of larger or less accessible molecules due to their conformation, thus improving the extraction selectivity. The modified cotton fibers are packed in a disposable syringe device where all the steps of the extraction take place. The ensuing fibers were evaluated for the extraction of several drugs providing the best results for cocaine (CO) and methamphetamine (MTA). These targets were extracted from saliva samples and finally determined by direct infusion mass spectrometry. The method provides limits of detection and quantification of 0.6 and 2 μg L-1 for CO and 0.8 and 2.7 μg L-1 for MTA, with precision values at the quantification level better than the 9% (expressed as relative standard deviation). Also, relative recoveries ranged from 115% to 111% for CO and MTA, respectively, demonstrating the applicability of the proposed method. Matrix effect, which has been statistically evaluated, is not significant, showing that the extraction selectivity can compensate the circumvent of the chromatographic separation.

中文翻译：

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用β-环糊精功能化的棉纤维作为选择性增强剂，用于唾液样品中可卡因和甲基苯丙胺的直接输注质谱测定

棉花是一种天然材料，具有良好的机械和化学性能。如果打算从水性基质中分离半极性或非极性分析物，则它呈现出亲水性表面，必须通过引入适当的基团进行改性。在这篇文章中，棉花用 β-环糊精进行了修饰，它呈现出一个疏水腔，可以容纳目标分子。由于其构象，空腔尺寸限制了较大或较不易接近的分子的进入，从而提高了提取选择性。改性棉纤维被包装在一次性注射器装置中，所有提取步骤都在那里进行。对随后的纤维进行了几种药物的提取评估，为可卡因 (CO) 和甲基苯丙胺 (MTA) 提供了最佳结果。这些目标是从唾液样本中提取的，最后通过直接输液质谱法确定。该方法为 CO 提供了 0.6 和 2 μg L-1 以及 MTA 0.8 和 2.7 μg L-1 的检测和定量限，定量水平的精度值优于 9%（表示为相对标准偏差）。此外，CO 和 MTA 的相对回收率分别为 115% 至 111%，证明了所提出方法的适用性。经统计评估的基质效应不显着，表明提取选择性可以补偿色谱分离的规避。定量水平的精度值优于 9%（表示为相对标准偏差）。此外，CO 和 MTA 的相对回收率分别为 115% 至 111%，证明了所提出方法的适用性。经统计评估的基质效应不显着，表明提取选择性可以补偿色谱分离的规避。定量水平的精度值优于 9%（表示为相对标准偏差）。此外，CO 和 MTA 的相对回收率分别为 115% 至 111%，证明了所提出方法的适用性。经统计评估的基质效应不显着，表明提取选择性可以补偿色谱分离的规避。