Institute of Chemistry, University of Campinas, Cidade Universitária Zeferino Vaz, Barão Geraldo, Campinas, São Paulo, Brazil.
Electrophoresis. 2011 Apr;32(9):1074-9. doi: 10.1002/elps.201000580. Epub 2011 Apr 4.
Leaf-cutting ants cause large losses in several crops around the world. In the ant species Atta sexdens, each colony comprises up to 5 million individuals. In order to keep a close connection among such a large number of individuals, an efficient chemical communication system is necessary. Among other different substances, these animals use alkylpyrazines to mark their trails and to guide ant workers from the nest to their sources of food. In this study, CE-UV was used to apply a method for qualitative analysis of venom gland components of leaf-cutting ants. Mobility of these compounds proved to be a function of the ionization capability of these bases as well as their volumes. Migration order was thoroughly explained in terms of such parameters. The best analysis conditions were achieved with a BGE composed by 0.8% formic acid plus 20% methanol in water, hydrodynamic injection, and application of external pressure. Such analysis conditions may be easily applied in CE-MS analyses as well. CE-UV analyses proved to be as adequate as GC to analyze such compounds due to system detectability (LD ≅ 0.005 mmol/L), separation efficiency (from 5.07×10(4) to 1.23×10(5) theoretical plates), and resolution (minimum of 2.35). In addition, analysis time was ca. 15 min, which shows another advantage of CE analysis when compared with GC. Although the analytes are found in concentrations as low as 50 ng/venom glands, four putative pyrazine ring moiety substances could be detected in real samples, due to sample stacking and use of a capillary with extended detection cell.
切叶蚁会对全世界的几种作物造成巨大损失。在切叶蚁属 Atta sexdens 中，每个蚁群最多可由 500 万只个体组成。为了保持如此庞大数量个体之间的紧密联系，需要一种有效的化学通讯系统。除了其他不同的物质外，这些动物还使用烷基吡嗪来标记它们的路径，并引导蚁群从巢穴到食物源。在这项研究中，CE-UV 被用于应用一种定性分析切叶蚁毒腺成分的方法。这些化合物的迁移性被证明是这些碱基的电离能力以及它们的体积的函数。迁移顺序根据这些参数得到了详细的解释。在含有 0.8%甲酸和 20%甲醇的水作为 BGE、水力进样和施加外部压力的最佳分析条件下，实现了最佳的分离。这些分析条件也可以很容易地应用于 CE-MS 分析中。CE-UV 分析由于系统检测能力（LD ≅ 0.005 mmol/L）、分离效率（从 5.07×10(4)到 1.23×10(5)理论塔板）和分辨率（最小 2.35），与 GC 一样适用于分析此类化合物。此外，分析时间约为 15 分钟，这表明 CE 分析与 GC 相比具有另一个优势。尽管分析物的浓度低至 50ng/毒腺，但由于使用了扩展检测池的毛细管和样品堆积，在实际样品中可以检测到四种可能的吡嗪环部分物质。
