1. Christian Vogel, Manfred Ramsteiner and Christian Adam
Deep Ultraviolet Raman Microspectroscopy – Novel Technique for the Characterization of Phosphorus in Soil
Christian Vogel, Manfred Ramsteiner and Christian Adam
BAM Federal Institute for Materials Research and Testing, Berlin, Germany
Paul-Drude-Institut, Berlin, Germany

2. Deep ultraviolet (DUV) Raman microspectroscopy
Introduction
Deep ultraviolet (DUV) Raman microspectroscopy
Detection of P-Phases in soil
Advantages and Disadvantages of DUV Raman microspectroscopy
Outlook
Conclusions

3. Deep Ultraviolet (DUV) Raman Microspectroscopy - Theory
from Asher, Analytical Chemistry, 1993, 65(2), 59A-66A
The electronic resonance enhancement effect can increase the intensity of the scattered light by a factor of 106.

4. Deep Ultraviolet (DUV) Raman Microspectroscopy – Enhancement Effect
UV/VIS
Guanosine-5´-monophosphate
from Dietzek et al., Chapter 2 in Confocal Raman Microscopy (Springer 2010)

5. Deep Ultraviolet (DUV) Raman Microspectroscopy - Fluorescence
from

6. DUV Raman Microspectroscopy of an Alluvial Soil
Alluvial Soil: pH(H2O) = 7.4; P = 0.36 wt.%
Instrument: HORIBA LabRam HR Evolution; Laser: 244 nm (Ar-Ion); Lateral Resolution: 1 µm;
Spectral Resolution: 8 cm-1; Time: approx. 1h; Imaged Area: 15 x 15 µm2

7. AlPO4 (Berlinite) Hydroxyapatite Ca-Phytate Fe-Phytate Na-Phytate 500
DUV Raman Spectra of Different Phosphates
AlPO4 (Berlinite)
Hydroxyapatite
Ca-Phytate
Fe-Phytate
Na-Phytate
500
1000
1500
2000
Wavenumber (cm-1)

8. Advantages and Disadvantages of DUV Raman Microspectroscopy
Detection of organic and inorganic
phosphates
High lateral resolution
(theoretical down to 150 nm)
Almost no samples preparation required
No fluorescence appears
Disadvantage:
Localization of P-phases

9. Outlook
Problem of P Localization Combination with laboratory micro X-ray
fluorescence (µ-XRF)
µ-XRF Mapping of the Alluvial soil
P Kα1
Ca Kα1
Si Kα1
Instrument: HORIBA XGT 7200; Area: 512 x 512 µm2; Lateral Resolution: 10 µm; Time: 5 min

10. Chemical state of inorganic and organic phosphates is detectable
Conclusions
Chemical state of inorganic and organic phosphates is detectable
by DUV Raman Microspectroscopy
Almost no sample pre-treatment is required
Combination with µ-XRF make it easier to localize P-phases