2.7.3. Holder and Stabilisation of the Liquid Samples

For determination of magnetic properties of liquid samples, we use pre-weighted 18 cm long and 6 mm narrow strip of standard office paper (80 g/m2), which was bent over the long side to the shape of V (Figure 7), which prevented the sample in the form of drop of 10 μL to spread to sides of the paper. Then the sample was dried in the vacuum for one hour or dried on air for 24 h at room temperature. After drying, the paper with the dry sample was weighted to obtain the actual dry weight of the sample knowing the weight of the paper without the sample. Type of the paper used for measurements of the liquid samples may differ, depending on the experiment, it can be laboratory filtration paper or standard office paper. For nanoparticle dispersion measurement, a strip of transparent foil was used, due to its ability to hold the drop of liquid in the desired shape. After this procedure, the sample was inserted to the plastic straw and attached to the sample rod.

**Figure 7.** Schematics of sample configuration with V-shaped paper and a standard plastic straw.
