Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
Anal Chem. 2012 Oct 2;84(19):8301-9. doi: 10.1021/ac3018229. Epub 2012 Sep 11.
Three different biocompatible polymers were tested and evaluated in order to improve the whole-blood biocompatibility of previously developed C18-polyacrylonitrile (C18-PAN) thin-film solid-phase microextraction (SPME) coating. Among all methods of modification, UV-dried thin PAN-over C18-PAN provided the best results. This coating presented reusable properties and reproducible extraction efficiency for at least 30 direct extractions of diazepam from whole blood [relative standard deviation (RSD) = 12% using external calibration and 4% using isotope dilution calibration]. The amount of absolute recovery for direct immersion analysis and based on the free concentration of diazepam in blood matrix was about 4.8% (desorption efficiency = 98%). The limit of quantitation (LOQ) for the developed solid-phase microextraction liquid chromatography-tandem mass spectrometry (SPME-LC-MS/MS) method for direct whole-blood analysis was 0.5 ng/mL. The optimized modification of the coating was then used for an extracted blood spot (EBS) sampling approach, a new sampling method which is introduced to address the limitations of dried blood spot sampling. EBS was evaluated using LC-MS/MS and direct analysis in real time (DART)-MS/MS, where, for a 5 μL blood spot, LOQs of 0.2 and 1 μg/mL, respectively, were achieved for extraction of diazepam.
为了改善先前开发的 C18-聚丙烯腈（C18-PAN）薄膜固相微萃取（SPME）涂层的全血生物相容性，测试并评估了三种不同的生物相容性聚合物。在所有的修饰方法中，经 UV 干燥的 PAN 覆盖 C18-PAN 提供了最佳的效果。这种涂层具有可重复使用的特性和可重复的萃取效率，至少可以从全血中直接萃取 30 次地西泮[使用外部校准的相对标准偏差（RSD）为 12%，使用同位素稀释校准的 RSD 为 4%]。直接浸入式分析和基于血基质中游离地西泮浓度的绝对回收率约为 4.8%（解吸效率为 98%）。开发的固相微萃取液相色谱-串联质谱（SPME-LC-MS/MS）方法用于直接全血分析的定量限（LOQ）为 0.5 ng/mL。然后，将该涂层的优化修饰用于提取血斑（EBS）采样方法，这是一种新的采样方法，旨在解决干血斑采样的局限性。使用 LC-MS/MS 和实时直接分析（DART）-MS/MS 对 EBS 进行了评估，对于 5 μL 血斑，分别提取地西泮的 LOQ 为 0.2 和 1 μg/mL。
