Insoluble particles

TDS Total dissolved solids, expressed as ppm (parts per million) or as mg/1 (milligrams per liter). Evaporate the water from a sample and the residue can be weighed. TSS Total suspended solids expressed in similar terms to TDS but representing a concentration of insoluble particles. 

In addition to the trace gases, many impurities, both soluble chemicals and insoluble particles, transfer from the atmosphere to the ice sheets and have measurable concentrations in ice cores. Such measurements are a window onto the... 

Examples of inferred enhancements of atmospheric primary aerosol concentration in the glacial atmosphere relative to the modem are factors of 4 to 7 for insoluble particles from continents, and 3 for seasalts (Alley et al, 1995), over Greenland. 

Colour formers such as compounds 243 and 245 are not inherently thermochromic. For example, they melt without any change in colour. However, they may be used to generate colour thermally, either irreversibly or reversibly, as composite materials. In thermally sensitive paper, the colour former and an acidic developer, usually a phenol, are dispersed as insoluble particles in a layer of film-forming material. When brought into contact with a thermal head at around 80-120 °C, the composite... 

Pharmaceutical scientists have developed improved suspension dosage forms to overcome problems of poor physical stability and patient-perceived discomfort attributed to some active ingredients. An important development aspect of any suspension is the ability to resuspend easily any settled particles prior to instillation in the eye and ensure that a uniform dose is delivered. It would be ideal to formulate a suspension that does not settle since the patient may not always follow the labeled instructions to shake well before using. However, this is usually not feasible or desirable since the viscosity required to retard settling of the insoluble particles completely would likely be excessive for a liquid eyedrop. The opposite extreme, of allowing complete settling between doses, usually leads to a dense layer of agglomerated particles that are difficult to resuspend. 

Dispersion of polymeric viscosifiers is often difficult because the initial contact of the untreated polymer with water results in very rapid hydration of the outer layer of particles which creates a sticky, rubbery exterior layer that prevents the interior particles from contacting water. The net effect is formation of what are referred to as nfish eyes" or "gel balls." These hamper efficiency by lowering the viscosity achieved per pound of gelling agent and by creating insoluble particles that can restrict flow both into the formation and back out of it. The normal remedy for this behavior... 

Greenhalgh, J.R., A. Birchall, A.C. James, H. Smith and A. Hodgson, Differential Retention of Pb-212 Ions and Insoluble Particles in Nasal Mucosa of the Rat, Phys. Med. Biol. 27 837-851 (1982). 

Radford, E. P., and E. A. Martell, Polonium-210 lead-210 ratios as an index of residence times of insoluble particles from cigarette smoke in bronchial epithelium, in Inhaled Particles IV, Part 2 (W. H. Walton, ed.) pp. 567-580, Pergamon Press, Oxford (1977). 

The Swinney adapter (Fig. 114). This handy unit locks onto a syringe already filled with your sample. Then you push the sample slowly through a Millipore filter to trap insoluble particles. This does not, however, get rid of soluble tars that can ruin the column. (Oh. Don t confuse the filters with the papers that separate them. It s embarrassing.)... 

An aqueous dispersion of a disperse dye contains an equilibrium distribution of solid dye particles of various sizes. Dyeing takes place from a saturated solution, which is maintained in this state by the presence of undissolved particles of dye. As dyeing proceeds, the smallest insoluble particles dissolve at a rate appropriate to maintain this saturated solution. Only the smallest moieties present, single molecules and dimers, are capable of becoming absorbed by cellulose acetate or polyester fibres. A recent study of three representative Cl Disperse dyes, namely the nitrodiphenylamine Yellow 42 (3.49), the monoazo Red 118 (3.50) and the anthraquinone Violet 26 (3.51), demonstrated that aggregation of dye molecules dissolved in aqueous surfactant solutions does not proceed beyond dimerisation. The proportion present as dimers reached a maximum at a surfactant dye molar ratio of 2 5 for all three dyes, implying the formation of mixed dye-surfactant micelles [52]. 

ISO 585 1990 Plastics - Unplasticized cellulose acetate - Determination of moisture content ISO 1061 1990 Plastics - Unplasticized cellulose acetate - Determination of free acidity ISO 1598 1990 Plastics - Cellulose acetate - Determination of insoluble particles ISO 1599 1990 Plastics - Cellulose acetate - Determination of viscosity loss on moulding ISO 1600 1990 Plastics - Cellulose acetate - Determination of light absorption on moulded specimens produced using different periods of heating ISO 1875 1982 Plastics - Plasticized cellulose acetate - Determination of matter extractable by diethyl ether... 

Fig. 18. Schematic representation of the intracellular enzymatic solubilization of a Gd(III)-based insoluble particles phagocytized by a macropahge.

A similar approach could be used to explain the mechanism of the paramagnetic effect caused by other, insoluble particles with encapsulated paramagnetic ions. 

The hydrochloric acid solution is added to speed solution of the nickel salts that otherwise lead to emulsions during separation. If no emulsion is encountered after mixing the petroleum ether and water solutions, no hydrochloric acid need be added. Similarly, the filtration through Celite filter aid is intended to remove finely divided nickel metal and other insoluble particles which complicate the washing procedure. If no particles are present, the filtration step should be omitted. 

An example of a schematic for sample treatment, extraction, and separation procedures is given in Simoneit, and it follows the method first used by Simoneit and Mazurek with minor modifications for data comparison purposes. The samples are powdered and dried, then typically extracted using ultrasonic agitation multiple times with a mixture of dichloromethane (CH2CI2) and methanol (3 1 v/v). The solvent extracts are filtered through an annealed glass fiber filter for the removal of insoluble particles, concentrated by rotary evaporation and then by a stream of filtered nitrogen gas. 

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