Drying samples solid

Freeze-Dried Samples. Solid Materials and Tissues. These are first cut into approximately 1-inch cubes, frozen on a Teflon cookie sheet in a freezer, and placed in 1200-ml. freeze-dry flasks to capacity. The flasks are attached to the freeze-dried (lyophilizer) manifold, the valves are opened to vacuum, and the flasks are evacuated. The water from the tissues is trapped on a condenser. The dry tissues (drying time about 2-3 days) are removed from the lyophilizer and compressed into thin-walled aluminum cans with a Carver Laboratory press fitted with a special die, at about 24,000 lb. pressure (total). From 150-250 grams of the dry material, representing 500-1000 grams of fresh tissue, can be packed into a single can. The cans are sealed with a hand sealer and set aside for counting. Samples can be removed from the cans at a later date for chemical analysis or beta-emitter analyses. 

The benzene used in this preparation should be reasonably free from toluene therefore use a sample of benzene supplied by dealers as crystalUsable benzene, i.e.y one which crystallises readily when cooled in ice-water. It should preferably be dried over calcium chloride and, immediately before use, filtered through a fluted filter-paper. The pyridine should also preferably be dried over solid potassium hydroxide and redistilled. 

The general reaction procedure and apparatus used are exactly as described in Procedure 2. Ammonia (465 ml) is distilled into a 2-liter reaction flask and to this is added 165mlofisopropylalcoholandasolutionof30g(0.195 mole) of 17/ -estradiol 3-methyl ether (mp 118.5-120°) in 180 ml of tetrahydrofuran. The steroid is only partially soluble in the mixture. A 5 g portion of sodium (26 g, 1.13 g-atoms total) is added to the stirred mixture and the solid dissolves in the light blue solution within several min. As additional metal is added, the mixture becomes dark blue and a solid (matted needles) separates. Stirring is inefficient for a few minutes until the mass of crystals breaks down. All of the sodium is consumed after 1 hr and 120 ml of methanol is then added to the mixture with care. The product is isolated as in Procedure 4h 2. After being air-dried, the solid weighs 32.5 g (ca. 100% for a monohydrate). A sample of the material is dried for analysis and analyzed as described in Procedure 2 enol ether, 91% unreduced aromatics, 0.3%. The crude product may be crystallized from acetone-water or preferably from hexane. 

Chlorofonn is too non-polar to dissolve the phenolic compounds under study, but it dissolves many of the monoterpenes, at least to some extent. Because the solubility of some monoterpenes into chloroform was low, different solvent/ solid ratios were tested. These were 50,20,10 and 5 1/kg of dry phloem. The extracts were bright yellow and the strongest colour was with the smallest solvent/solid ratio (51/kg). The colour of the solvent indicated that the solubility of the extractable compounds was not restricting the reaction even with the smallest solvent volume. The taste of the dry samples was evaluated by comparing them to the original phloem sample. The results showed that the mildest taste was in the phloem extracted with a solvent/solid ratio of 50 1/kg and 20 1/kg also had some effect on the taste. The taste of the chloroform-extracted phloem was stabile and it was the same after a week. 

Wet solids. Press out on filter paper, break up, let dry. The solid shouldn t stick to the sides of the sample vial. Tacky ... 

To help dry damp solids, place the damp solid on a piece of filter paper and fold the paper around the solid. Press. Repeat until the paper doesn t get wet. Yes, you may have to use fresh pieces of paper. Try not to get filter paper fibers in the sample, OK ... 

Fig. 18. The proton spin-lattice relaxation rate recorded as a function of the magnetic field strength plotted as the proton Larmor frequency for lysozyme samples. Dry ( ), hydrated to 8.9% ( ), 15.7% (O). 23.1% (A), and cross-linked in a gel ( ). The solid lines were computed from the theory. The solid lines are fits to the data using Eq. (4) with Rs given by Eq. (6). The two parameters adjusted are Rsl and b (97). The small peaks most apparent in the dry samples are caused by cross-relaxation to the peptide nitrogen spin (90,122).

Solvent Swelling and Extraction, The residue samples were extracted with pyridine at the boiling point to obtain the amount and composition of the extract. A portion of the dried, extracted solids was swelled in pyridine in order to estimate the density of crosslinks introduced by the preliquefaction process. The solvent swelling measurements were carried out according to the method of Green et al. (30,31). 

Solid samples are extracted with low-boiling solvents. As the polarity of the volatiles is different, a two-step extraction procedure is recommended, e.g. methylene chloride as the first solvent and diethyl ether as the second solvent [13]. The yield of the odorants is enhanced when the dry sample is soaked in water before the extraction procedure [14]. After filtration and drying, the extract is concentrated to approximately 50 mb and is then freed from the non-volatile material by using the solvent-assisted flavour evaporation (SAFE) method (Sect. 16.2.2.2). 

Once a bulk sample is selected, a laboratory sample must be prepared for analysis (Figure 28-2). A coarse solid sample should be ground and mixed so that the laboratory sample has the same composition as the bulk sample. Solids are typically dried at 110°C at atmospheric pressure to remove adsorbed water prior to analysis. Temperature-sensitive samples may simply be stored in an environment that brings them to a constant, reproducible moisture level. 

In-process controls such as stratined sampling, process analytical technology (PAT) application, and blend homogeneity. Assess modincation of dissolution through optimization of API characteristics and then perform assessment of specialized technologies [hot-melt extrusion (HME), spray-dried dispersion, solid dispersion, etc.] for long-term resolution... 

Sludges and solid wastes are acidified and combined with MgS04H20. This can dry the sample by forming MgS04-7 H20. Samples should not be heated for drying because heating the acidified sample can decompose many component compounds. The dried sample is then serially extracted with an appropriate extraction solvent and analyzed as above. 

Corn stover was harvested from south Hungary in the fall of 2001. The selected and washed straw was air-dried to an average 90% dry matter (DM) content. The air-dried material was ground and sieved, and the fraction with a particle size of 2-5 mm was used. The composition of this material and also the washed, solid fibrous fraction remaining after pretreatment was determined using Kaar s (19) method. To measure the total ash content, approx 0.5 g of dried sample was placed in a crucible, ignited at 550°C for 3 h, cooled in a desiccator, and weighed. 

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