Average content limits

It has been found in the Netherlands by proficiency testing that the average content of most pharmacy preparations lie between 95 % and 105 % of the stated content. So when accepting a content limit of 90-110 %, the product will be released without further consideration if an assay result is between 95 % and 105 %. Trends in results (up or down) should be investigated as part of product quality reviews. 

In the Netherlands it is commOTi to use a requirement of 3 % as a limit to the deviation of the average mass towards the calculated mass for capsules and suppositories. Eor single dose powders this requirement is 5 %. In practice these limits appear to be acceptable and are achievable. When these limits are exceeded, then there are, in principle, two possibilities reject the preparatirai or check the average content. When the content comphes, the preparatirai need not be rejected on the basis of the average mass discrepancy. However the cause of the deviation should be investigated and traced and corrective measures should be taken for future batches. 

Methionine Animal proteins contain 2-4% of methionine, whereas plant proteins contain only 1-2% (average content is 1.7%). Methionine is the limiting amino acid in legumes. Methionine (and cysteine) is present only in small amounts in histones and is completely lacking in protamines. 

A European Directive, 85/210/EEC, limits benzene content to 5% by volume in all gasolines regular, premium, with or without lead. This level is easily achieved, since the average value in 1993 was less than 3%. in France, for example, average benzene concentrations of 1.7% and 2.6% were reported for leaded and unleaded premium fuels, respectively, in 1993. 

Exhaust emissions of CO, unbumed hydrocarbons, and nitrogen oxides reflect combustion conditions rather than fuel properties. The only fuel component that degrades exhaust is sulfur the SO2 concentrations ia emissions are directly proportional to the content of bound sulfur ia the fuel. Sulfur concentrations ia fuel are determined by cmde type and desulfurization processes. Specifications for aircraft fuels impose limits of 3000 —4000 ppm total sulfur but the average is half of these values. Sulfur content ia heavier fuels is determined by legal limits on stack emissions. 

Cement kilns can handle quite a lot of different materials. In most cases the input material should be chipped or shredded. Licenses often limit the PVC and chlorine input to l%-2% chlorine in waste. It is said that chlorine also has a negative impact on the quality of the clinker if it is available in too high quantities. The content in clinker seems to be limited to some 0.1% at maximum, and hence the average chlorine content of all fuels used combined may have to be somewhat lower. This implies that waste with a high chlorine... 

The calculated conversions presented in Table VIII used Eq. (57). They are quite remarkable. They reproduce experimental trends of lower conversion and higher peak bed temperature as the S02 content in the feed increases. Bunimovich et al. (1995) compared simulated and experimental conversion and peak bed temperature data for full-scale commercial plants and large-scale pilot plants using the model given in Table IX and the steady-state kinetic model [Eq. (57)]. Although the time-average plant performance was predicted closely, limiting cycle period predicted by the... 

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