Determination of Na+, K+ and Ca2+ of Apoplast of Poplar Stems by Atomic Absorption Spectrometry with Microdialysis Method

The dialysis for three species of populus stems apoplast was carried out with a microdialysis system, and the concentration of Na+, K+ and Ca2+ in the dialysate was directly measured by the graphite furnace atomic absorption spectrometry (GF-AAS). The flow rate of perfusate was 1 μL min−1 and the cut-off molecular weight of probe was about 30 kDa. The test technique was applied to the research of poplar biochemical physiology due to its perfect characteristic of real-time and non-destructive detection. The recovery of the method was 95.8%–103.1%. The content of Na+ in Populus wutunensis, Populus simonii × P.euphratica” × P.sp and Populus simonii × (Populus pyramidalis + Salix matsudana) were 1034–1156 μg L−1, 1493–1611 μg L−1 and 1586–1703 μg L−1, respectively, K+ was 1012–1237 μg L−1, 941–964 μg L−1 and 1095–1201 μg L−1, and Ca2+ was 4976–5237 μg L−1, 4786–5042 μg L−1 and 5893–6142 μg L−1. This method could provide reliable data for the investigation of the change of ion concentration of plant to all kinds of external environment stress.

The needle probe is inserted as such or via a guide cannula into the tissue of a stem. The magnified membrane region illustrates net diffusion of a compound (analyte) of interest (open circles) into the probe, and the net diffusion of the calibrator (closed circles), which has been added to the perfusate, from the probe to the extracellular space.Figure optionsDownload as PowerPoint slide