Simple and rapid CE‐UV method for the assessment of trail pheromone compounds of leaf‐cutting ants' venom glands

Abstract

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.

Biotoxin sensing in food and environment via microchip

“…These animal toxins are used for two primary functions, that is, predation (as spider, snake, scorpion, jellyfish, wasp) or defense (as bee, ant, termite, honeybee, wasp, poison dart frog). CE, chromatography, or MS methods have been conducted in animal toxin determination, while microchip‐sensing method plays an emerging important role. Compared to MS determination, immunochemical sensing of acetylcholinesterase inhibited by nerve agents is under development .…”