Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany.
Electrophoresis. 2011 Apr;32(8):920-5. doi: 10.1002/elps.201000417. Epub 2011 Mar 10.
In this report, a new approach for the fast determination of hydrazine compounds (hy) in complex matrices is presented. The experimental protocol is based on poly(methylmethacrylate) (PMMA) microchip separations with contactless conductivity detection using a compact portable device, which integrates all separation and detection components. Three hy (hydrozine (Hy), methylhydrazine (MH), and 1,1-dimethylhydrazine (UDMH)) were separated within < 30 s at a separation voltage of 3.8 kV using a L(-)-histidine/2-(N-morpholinoethanesulfonic acid) (His/MES) buffer (25:50 mM, pH 5.87). The contactless conductivity detection enables detection limits for Hy, MH, and UDMH of 11.9, 35.5, and 337.8 ng/mL, respectively, with linear concentration dependence up to 10 μg/mL. In complex matrices such as soil samples or river water, interferences were eliminated by implementing ultrasound-assisted headspace single-drop microextraction of hy under strongly alkaline conditions, using an aqueous drop of His/MES buffer as the extractant phase. The incorporation of this miniaturized sample preparation step led to improved limits of detection for Hy, MH, and UDMH of 6.5, 15.3, and 11.4 ng/mL, respectively. The overall protocol demonstrates a promising approach for interfacing chip electrophoresis with real-world applications.
在本报告中，提出了一种快速测定复杂基质中肼类化合物（hy）的新方法。实验方案基于聚甲基丙烯酸甲酯（PMMA）微芯片分离，采用紧凑的便携式设备进行无接触电导检测，该设备集成了所有分离和检测组件。在分离电压为 3.8 kV 的条件下，使用 L(-)-组氨酸/2-(N-吗啉乙磺酸)（His/MES）缓冲液（25:50 mM，pH 5.87），三种 hy（肼（Hy）、甲基肼（MH）和 1,1-二甲基肼（UDMH））在 < 30 s 内得到分离。无接触电导检测使 Hy、MH 和 UDMH 的检测限分别达到 11.9、35.5 和 337.8 ng/mL，线性浓度依赖性高达 10 μg/mL。在土壤样品或河水等复杂基质中，通过在强碱性条件下实施超声辅助顶空单滴微萃取，以 His/MES 缓冲水溶液为萃取相，消除了干扰。将这种微型化的样品制备步骤纳入其中，使 Hy、MH 和 UDMH 的检测限分别提高到 6.5、15.3 和 11.4 ng/mL。整个方案证明了将芯片电泳与实际应用接口的有前途的方法。
