Whatman 41 filter paper

The dried leaves of Thymus vulgaris and Mentha piperita and the roots of Zingiber officinale were cleaned carefully, washed with distilled water, and then dried in the dark for three days; they were sliced and cut into fine pieces. The dried fine species were ground carefully into fine powder. One gram of each fine powder was added to 100 mL of a beaker containing distilled water and stirred at 30°C for 2 days. These aqueous extracts were filtered twice, initially through the Whatman 41 filter paper and finally through a 0.22 μm syringe filter, just before they were incorporated into the AgNO₃ solution. When the final sterilized extracts were ready, they were kept in the refrigerator at 4°C wrapped in aluminum foil so they could be used again.

Fresh sea grapes (C. racemosa) are collected in the shallows (5–10 m above sea level) of the Mantehage seawater, north of Sulawesi, Indonesia. Botanical identification and authentication are confirmed in the Department of Pharmacology, Faculty of Mathematics and Natural Sciences, Sam Ratulangi University, Indonesia. Specimens are collected for future reference. Sea grapes (whole-body) are thoroughly rinsed with water, air-dried at room temperature, and baked at 40°C, then smoothed with an electric grinding. Furthermore, in the extract preparation, coarse powder (1,000 g) is macerated with 96% ethanol for 72 h with each extraction carried out in triple, resulting in a yield of 34%. The extract is roughly filtered with Whatman 41 filter paper. The total filtrate is glued and evaporated at 40°C in the RV 8 IKA rotary evaporator under reduced pressure (100 mbar) for 90 min and evaporated in an oven at 40°C to produce the powder extract. The extract is stored in a refrigerator at a temperature of 10°C until used in the research. The extract powder is encapsulated.

Oryza sativa L. husk was washed with distilled water and oven dried at 80 °C. Dried husk (15 g) was acid leached by 250 mL of 10% of HCl and refluxed for 2 h. Treated husk was washed with distilled water till pH reaches to 7 and dried in oven at 80 °C. The material was burned in muffle furnace at 700 °C for 2 h to remove incorporated hydrocarbons. 2 g calcined Oryza sativa L. husk ash (HA) was again treated with 30 ml of 10% HCl for two hours and washed with distilled water to attain pH 7 and dried overnight at 80 °C. The 0.5 g pretreated husk ash was refluxed for two hours with 20 mL of 1 N NaOH to obtain sodium silicate solution. This solution was allowed to cool at room temperature, filtered with Whatman 41 filter paper and neutralized with 1 N HCl with constant stirring until gel was formed at pH 7. Gel was allowed to age for 18 h then broken by adding water and stirred. Gel was then centrifuged at 6000 rpm for 5 min. The centrifuged material was dried at 80 °C to obtain silica xerogel. The silica obtained was 98.6% pure^{32 (link),33 (link)}.

Cultivation of Spirulina sp. in Spirulina Media with growing conditions at 28 °C and lighting 3000 lx. After 14 days of cultivation, cells were harvested by centrifugation and washed several times to remove the culture medium and filtered with whatman 41 filter paper to reduce the water content. Biomass was dried in an oven at 60 °C for 24 h until dry, then mashed with a mortar and sieved to a size of 40 mesh [13 (link)]. The immobilization process was carried out by taking 100 mL of sodium silicate Na₂SiO₃ solution and dropping it with concentrated HCl to pH = 7. The mixture was stirred until aqua-gel (hydrogel) was obtained, and 3 grams of microalgae biomass was added. Then dried in an oven at a temperature of 80 °C to form dry silica [14 (link)]. Characterization of functional groups was carried out on the biomass before and after the adsorption process by FTIR.

We used dissolution tests in order to better understand the dynamics of doping the phosphate glasses. These tests were performed for all the powder samples under the same experimental conditions, deionized water as an immersion liquid at a temperature of 37 °C, which we chose to ensure a close resemblance to the temperature of the human body. The relative weight loss (W_loss) of each sample after immersion was expressed as a percentage and calculated according to the following equation: $$W_{loss}=\frac{m_i-m_f}{m_f}\times 100$$
where m_i is the initial weight of each sample, and m_f is the weight after immersion in 10 mL deionized water.
For each sample, 100 mg was immersed in 10 mL of deionized water at 37 °C with continuous orbital shaking (300 rpm) on a titer plate shaker (Heidolph™ Titramax 1000, Hamburg, Germany) for 14 days. After incubation, the resulting suspensions were decanted and vacuum-filtered using Whatman-41 filter paper. The resulting sediment was then dried at RT for 3 days and weighted using a Precise XT220A analytical balance with a self-calibration system (SCS).