Raw material purity

Raw Material Purity Requirements. The oxygen process has four main raw materials ethylene, oxygen, organic chloride inhibitor, and cycle diluent. The purity requirements are estabHshed to protect the catalyst from damage due to poisons or thermal mnaway, and to prevent the accumulation of undesirable components in the recycle gas. The latter can lead to increased cycle purging, and consequently higher ethylene losses. 

This input to design refers to the long-term stability of the raw material sources for the plant. It is only of importance where the raw materials can or do contain impurities which can have profound effects on the corrosivity of the process. Just as the design should cater not only for the norm of operation but for the extremes, so it is pertinent to question the assumptions made about raw material purity. Crude oil (where HjS, mercaptan sulphur and napthenic acid contents determine the corrosivity of the distillation process) and phosphate rock (chloride, silica and fluoride determine the corrosivity of phosphoric acid) are very pertinent examples. Thus, crude-oil units intended to process low-sulphur crudes , and therefore designed on a basis of carbon-steel equipment, experience serious corrosion problems when only higher sulphur crudes are economically available and must be processed. 

Assessment of raw materials (purity hidden ingredients supplier monitoring)... 

Developing a management system is not a one-time project. It must be able to manage even subtle material, equipment or personnel changes that may have a significant effect on the safety of the operation. These may include a minor change in raw material purity, a modification to the shape of a vessel where heat transfer is important, or a change in how an operation is supervised. 

It is due to these stringent requirements on raw material purity along with the type of glass making oxides used that optical glasses in general are rather expensive compared to other commercial glasses. 

Tablet potency was found to be related to raw material purity and tablet weight as follows ...

The slope of the regression plane was found to be positive for both tablet weight and raw material purity, as we would expect. The slope for tablet weight was statistically significantly different from 0 at a = 0.01, while the slope for purity was significant at a = 0.05. 

The concentration of active ingredient D1 for batch to batch is shown in Figure 13. The mean potency of all batches is 0.1 mg/5 ml above target. The control chart did not respond to tests for unnatural patterns and trends. It is noteworthy that the calculated UCL (16.7 mg/5 mL) for the 20 batches in this study exceeds the release specification for the product (15.5 to 16.5 mg/5 ml. A probability thus exists that a batch may eventually fail to meet the release criteria. Raw material purity is not a factor in the potency of an individual batch because it is taken into consideration at the time of manufacture. A possible explanation for the wide historical control limits is the assay methodology for... 

It must be remembered that these are theoretical calculations, and final results may be different due to raw material purities, transferring efficiencies, and the degree of conversion. 

For industrial applications, such as fibres, films and bottles, the chain length n should be between 700 and 1400. This is significantly higher than with partially aromatic polyesters like PET and PBT, where n is between 100 and 200. Therefore, the requirements on both raw material purity and technical effort are much higher. 

Drug analysis encompasses tests on raw materials (purity criteria), pharmaceutical or veterinary formulations, and a number of other, more complex matrices such as foods of animal origin, drinks, and foodstuffs that are conducted for clinical, forensic, or veterinary purposes involving a variety of matrices including blood, urine, and tissues. Pharmaceutical analysis is restricted to drug analyses in raw materials and pharmaceutical formulations in some instances, it also includes clinical analyses. Pharmaceutical analyses involve the determination of not only active components but also impurities, excipients, the stability of active components (and their degradation intermediates or end-products), and other parameters such as content uniformity, solubility, and dissolution rate. 

The relative degree of crystallinity and the geometrical aspect ratio of obtained cellulose nanocrystals, depend on cellulose origin and the processing conditions, such as time, temperature, and original raw material purity. 

Marvola M, Koponen A, Hiltunen R, Hieltala P 1981 The effect of raw material purity on the acute toxicity and laxative effect of sennosides. J Pharm Pharmacol 33 108-109... 

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