Particles, such as atmospheric dusts, suspension material or nanoparticles, play a significant role in human health as well as in the global transport of substances. In our laboratory we determine the mass of particles as well as the particle size distribution of a sample. The mineralogical composition allows a statement regarding the origin of the particles (geogenic, anthropogenic, but also assignment to lithological units). The analysis is supplemented by a comprehensive investigation of the element contents, which includes main and trace elements as well as other parameters. Often the mobile fraction is also of interest, which we can determine by leaching with appropriate solvents.
Particles, such as atmospheric dusts, suspension material or nanoparticles, play a significant role in human health as well as in the global transport of substances. We determine the particle mass gravimetrically. The exact weighing is performed in a climatic chamber (T: 21±1°C, relative humidity: 40%). The determination of the particle size distribution is performed for filter samples by optical microscopy in our laboratory or by partners at the DWD in Freiburg. For loose samples we use grading curves or for silty-clay samples an automated method based on the sedimentation rate.
We are happy to advise you on the right method for your problem.
Filter samples
Method | Parameter | Device |
Gravimetry | Mass/quantity | Satorius SE2-F ultra-microbalance Weighing range: Repeatability: |
Optical microscopy | particle size, particle shape, particle type | various microscopes |
Loose samples
Method | Parameter | Device |
Sieving | Grain size composition, grading curves | Various sieves from silt to gravel (40 µm - 2 cm) |
Sedimentation | Direct particle size distribution of silt fraction (2-63 µm); Calculation with grading curve enables calculation of clay fraction | Pario, METER Group |
The mineralogical composition allows a statement regarding the origin of the particles (geogenic, anthropogenic, but also assignment to lithological units). Furthermore, the mineralogical composition has an influence on transport behavior, abrasiveness, light scattering and risk to human health.
We can determine the mineralogy of your particles by X-ray diffraction (XRD) on ground powder samples or investigate it by polarized light microscopy or scanning electron microscopy (*REM; Petrology and Mineralogy Department). It is also possible to determine the mineralogy directly on suitable filters by means of the methods mentioned.
If you have any questions, we will be glad to help you.
Radiographic analysis (D8 Discover, Bruker)
Method | Sample material | Statement |
Powder diffraction (XRD) | Pulverized particles: Amount > 10 mg - 2 g Occupied acetate filters | Qualitative, semi-quantitative mineral stock |
Texture preparations (unconditioned, glycolized, burned) | Gravimetrically separated clay constituents | Specific characterization of clay minerals, identification of swellable clay minerals |
Microscopy
Method | Instrument | Statement |
Polarized light microscopy | Various models | Mineral composition, grain size, grain shape, |
Scanning Electron Microscope (SEM) coupled with X-Ray Fluorescence* | Tescan Vega | High resolution information (nm to µm) on mineral composition, grain shape, surface texture, etc. |
The elemental composition of the investigated particles, including multivariate statistical methods or enrichment factors, allows source identification. The calculation of the contribution of the particulate load in material flow calculations is also based on a precise knowledge of the chemical composition of the transported particles. Especially for atmospheric particles, the content of toxic elements must be known for a hazard assessment.
We enable the determination of their element contents in various particles either directly on the solid or after acid digestion by means of ICP-MS or ICP-OES. The elements that can be determined depend on the sample matrix, the element concentration and the method used. Specific individual particles can be examined by scanning electron microscopy (*REM; Department of Petrology and Mineralogy) after embedding and vapor deposition with regard to their elemental composition.
We will be pleased to advise you on your questions.
Procedure | Element spectrum | Device |
X-ray fluorescence (XRF), angle dispersive, Melting tablet | main elements (Na, K, Ca, Mg, Al, Si, Fe, Mn, Ti, P), loss on ignition | S4 Explorer, Bruker AXS |
X-ray fluorescence (XRF), energy dispersive Melt tablet/ | major elements (K, Ca, Fe, Mn, Ti) div. trace elements | Epsilon 5, PANanlytical; Epsilon 4, PANanlytical; EDX 8000; Shimadzu |
Carbon-sulfur analyzer (CSA) | TC, TOC, TIC, TS | CS-2000, ELTRA |
Scanning electron microscope (SEM) coupled with X-ray fluorescence*. | High-resolution information (nm to µm) on mineral composition, grain shape, surface texture, etc. | Tescan Vega |
| Laser Ablation (LA)-ICP-MS | High resolution geochemistry (µm range) | Excimer+ Laser 193 nm (Teledyne Cetac) ICP-MS (Element XR, Thermo Fisher) |
div. digestions | Major and trace elements | ICP-MS (iCAP RQ, Thermo Fisher); |
Fine dust particles can penetrate deep into the lungs. There, the soluble components in particular pose an increased risk to human health. In the case of suspended material in rivers, it is of interest which elements can be mobilized, e.g. by changing the water composition (freshwater/saltwater; tributaries/tributaries).
We determine the mobile fractions in your particles by leaching with appropriate solvents (water, salt solution, dilute acids, etc.). These are then analyzed for the desired elements using our wet chemical methods.
We would be pleased to inform you about our possibilities.
Methods | Element spectrum / | Device |
Metals | ||
Multielement methods | ||
ICP-MS | main elements (Na, K, Ca, Mg) div. trace elements (e.g. Al, Au, Ag, As, B, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Pb, P, Rb, Zn, U) PGEs, SEE ng/L to mg/L, ppt to ppm (depending on matrix/element) | iCAP RQ, |
ICP-OES | Major elements (Na, K, Ca, Mg) Selected trace elements (e.g. Ba, Fe, Mn, S, Si, Sr) also suitable for salt-heavy samples µg /L to mg/L, ppb to ppm (depending on matrix/element) | Varian 715ES (radial) |
Single element methods | ||
AAS (flame) | Single elements especially Na, K, Ca, Mg mg/L, ppm - range | AAnalyst 200, |
AAS (graphite furnace) | Single elements e.g. Pb, Cd, Mn, As, Se µg/L, ppm - range | AAnalyst 600, Perkin Elmer |
AAS (hydride, FIAS) | Se, As µg/L, ppm - range | FIMS 400, coupled with AAnalyst 200. Perkin Elmer |
Anions | ||
Ion chromatography (IC) | F, Cl, Br, NO3-, PO43-, SO42- | Dionex, ICS-1000; separation column IonPac As14 Supressor ERS 500 Eluent NaHCO3/Na(CO3)2 |
Photometry | Phosphate (DIN En ISO 6878) Chromate (US EPA et al. 1992) >0.1 mg/L, ppm | Lamda2, Perkin Elmer |