Compounding process quality control

The trace hydrocarbon compounds listed can have an effect in the commercial use of butadiene. This test method is suitable for use in process quality control and in setting specifications. 

Quality Control. Reproducible production of perfumes requires careful quality control of all materials used as well as the compounding process itself. The use of analytical tools has iacreased over the years with their availability, but there can be no substitute for organoleptic evaluation. The human nose is far more sensitive than any analytical instmment for certain materials, yet it is also quite limited as a quantitative tool and is subject to fatigue. There are also weU-documented examples of specific anosmias ia iadividuals, ie, iaability to smell certain odor types, which is somewhat analogous to color-blindness. 

The so-called flow temperature cannot be considered to be either the processing temperature or the maximum service temperature. It is obtained using the highly arbitrary Rossi-Peakes flow test (BS 1524) and is the temperature at which the compound is forced down a capillary of fixed dimensions by a fixed load at a specified rate. It is thus of use only for comparison and for quality control purposes. Since the rates of shear and temperatures used in processing are vastly different from those used in this test, extreme caution should be taken when assessing the result of flow temperature tests. 

The production of a rubber lining includes the preparation of the rubber compound followed by processing to form the lining sheet, substrate preparation, lining application, vulcanisation and inspection. All these stages require thorough quality control, especially compound manufacture and sheet preparation, as chemical resistance depends on satisfactory dispersion of the individual ingredients and undetected flaws in the sheet will cause problems in service. 

It Is now a relatively straightforward matter to analyze commercial pesticide mixtures for nitrosamlne contamination as part of the normal quality control process (2.18). and, as Illustrated above, some of the major contamination problems have begun to be solved by means of technological Improvements. If further research brings about the circumstance In which there Is no detectable N-nItroso compound In any pesticide sold an here, will that mean that pesticide use Is safe from nitrosamlne-formatlon problems I believe that considerably more research must be done before a responsible answer to this question can be given. To elaborate on this position, let me focus on the herbicides for a moment. 

Since surfactants are commercially produced by means of large-scale chemical processes, complex mixtures of homologues and isomeric compounds, e.g. non-ionics of the alkylethoxylate type that may differ in length of alkyl as well as polyether chains, can result. The determination and differentiation of the products in quality control during production and trade is a somewhat easier task. However, more difficulties arise in the analysis of the compounds of these mixtures and formulations in environmental samples. 

Quality assurance is concerned with maintaining the quality of products to set standards. This embraces the control of incoming materials, the control of compounds produced, the control of manufacturing processes and guaranteeing as far as possible the quality of the final product. Quality assurance schemes utilise physical testing methods as a most important part of their system. In fact most of the standardised test methods are principally... 

Basic Protocols 3 through 9 are primarily useful as quality control measures. They are rapid, usually within 30 min, given reagent preparation. The results are used to monitor the quality of a process. These results support established values for high quality citrus oil. Basic Protocols 1 and 2 are more involved and are better suited for research purposes. The equipment is more sensitive and also more expensive. Furthermore, the strength of the GC analysis can be enhanced by the addition of a mass spectrometer to identify either contaminates or unknown compounds present in a sample. 

The desired citrus flavor is the result of volatile compounds in specific proportions. Citrus oils have unique composition profiles depending on the cultivar, the processing conditions, and the storage conditions. There have been more than 200 different compounds identified in citrus oils. However, the degree of unsaturation in monoterpenes leads to rapid oxidation and unstable compounds. The reactivity and volatility of citrus oils require strict quality control protocols. 

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