Fig. 7
From: Analysis of trace metal distribution in plants with lab-based microscopic X-ray fluorescence imaging
Quantified fluorescence maps of the Zn K-edge of N. caerulescens for leaves at different stages of development from rosette (0) to the mature leaves at the base of the plant (4). The grey scale on the right side represents the concentrations from 0 (black) to maximum (white). White corresponds to: 12,605 mg kg−1 for the leaf at position 4 (base), 3389 mg kg−1 for position 3, 3041 mg kg−1 for pos 2, 2602 mg kg−1 for pos 1, and 2724 mg kg−1 for the leaf at position 0 (rosette). These values are corrected to match the difference in mass between the fresh leaves in µXRF with dry mass in ICPMS. Point distance is 15 µm and integration times are: 25 ms for 0, 3 ms for (1)–(4). Pixels are averaged (5 × 5 to 9 × 9) in the quantified images due to limitations of the software to deal with high pixel number. The full resolution zoom shows the epidermal metal storage cells [18]