Solid-handling techniques

Solid-handling techniques Extraction techniques Extraction time (min) ... 

One of the most important bulk solids handling techniques in a solids handling plant is the movement of material suspended in a stream of air over horizontal, inclined or vertical surfaces, ranging from a few to several... 

The growth of lactose crystals in ice cream results in a serious texture defect known as sandiness. It is usually caused by temperature fluctuations, high serum solids in the mix, and high cabinet storage temperatures. The ratio of serum solids and moisture must be controlled. Hydrocolloids have some effect on controlling sandiness, but not as much as proper handling techniques and formulation. 

Nondestructive radiation techniques can be used, whereby the sample is probed as it is being produced or delivered. However, the sample material is not always the appropriate shape or size, and therefore has to be cut, melted, pressed or milled. These handling procedures introduce similar problems to those mentioned before, including that of sample homogeneity. This problem arises from the fact that, in practice, only small portions of the material can be irradiated. Typical nondestructive analytical techniques are XRF, NAA and PIXE microdestructive methods are arc and spark source techniques, glow discharge and various laser ablation/desorption-based methods. On the other hand, direct solid sampling techniques are also not without problems. Most suffer from matrix effects. There are several methods in use to correct for or overcome matrix effects ... 

Performance of sample handling techniques for the extraction of non-ionic surfactants from solid matrices... 

Sample preparation refers to a family of solid/liquid handling techniques to extract or to enrich analytes from sample matrices into the final analyte solution. While SP techniques are well documented, few references address the specific requirements for drug product preparations, which tend to use the simple dilute and shoot approach. More elaborate SP is often needed for complex sample matrices (e.g., lotions and creams). Many newer SP technologies such as solid-phase extraction... 

For work with solutions, and in particular with solid materials, precautions against electrostatic charging and the effects of air currents have to be taken, and standard radiochemical techniques should be used. The handling techniques required for other technetium isotopes such as Tc are described below (Scheme 2). 

Economic Aspects. Table 13 summarizes prices and shipping methods for the principal borate products as of January 1991. Within the United States most shipments are by rail, and additional charges are made for split cars, tmck shipments, palletized shipments, etc. Prices are fob Southern California. In general, the borates are stable solids and require no special handling techniques with the possible exception of dust collection. 

Pure solid or liquid is highly explosive evaporation of a solution in liquid 02 results in explosion4 liquid explodes on contact with organic liquids and oxidizable materials2 safe handling techniques have been described,5"7 and interaction with organic compounds has been reviewed.8... 

The study of polonium chemistry is difficult owing to the intense a radiation, which causes damage to solutions and solids, evolves much heat, and makes special handling techniques necessary for protection of the chemist. 

When designing the bulk solids handling equipment to minimize adverse two-phase flow effects, the following general design techniques are beneficial ... 

If the sample is a solid, dissolution is required prior to flame AAS. This slows the process and opens the opportunity for contamination during the various handling steps. It would be very convenient if there were a way to introduce solid samples directly into the flame. Papers have occasionally appeared in the literature but no solid sampling technique for flame AAS has been found to be generally acceptable for biological samples. 

Additional solid-state techniques are covered in the chapter on solid-state analysis and polymorphism. The determination and control of the solid-state form, in respect of both crystal structure and particle characteristics, are important. The physical properties of the dmg substance will influence its behaviour during handling processes and formulation, and can have a dramatic effect on dissolution, solubility and therefore bioavailability. 

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