Test methods solution preparation

The reaction is carried out in ethereal solution it gives the best yields when alkylmagnesium chlorides are used the corresponding alkyl chlorides are by-products. The process has its main interest for preparation of primary amines whose amino group is attached to a secondary or tertiary carbon atom. Examples of its use and a tested. method of preparing chloramine are given in a review by Theilacker.1217 Also the unstable chloramine may be replaced by methoxylamine, which is easier to handle.1218... 

Recommended practice for examination and evaluation of pitting corrosion Test method for determining susceptibility to stress corrosion cracking of high-strength aluminium alloy products Test method for pitting and crevice corrosion resistance of stainless steels and related alloys by the use of ferric chloride solution Recommended practice for preparation and use of direct tension stress corrosion test specimens... 

Sander and wise have proposed a test method to determine the bonding chemistry used to prepare octadecylsiloxane column packings based on the relative retention of three polycyclic aromatic hydrocarbons, benzo[a]pyrene (BaP), phenanthro-phenanthrene (PhPh), and l,2 3,4 5,6 7,8-tetrabenzonaphthalene (TBN) eluted with the mobile phase acetonitrile-water (85 15) [52,67,199,210]. On monomeric phases the test solutes elute in the... 

Validation of automated systems must demonstrate a lack of contamination or interference that might result from automated transfer, cleaning, or solution preparations procedures. Equivalency between the results generated from the manual method and the data generated from the automated system should be demonstrated. Since sensitivity to automated dissolution testing may be formulation related, qualification and validation of automated dissolution equipment needs to be established on a product-by-product basis (8,13) (see also Chapter 12 for a more detailed description of automation issues). 

Accuracy. In the quantitative method that is used to measure the heavy metal quantity in the drug substance, the accuracy is usually represented by the recovery rate obtained from a spiked recovery test where lead is added to the samples. Since the heavy metals limit test specified in monograph specifications is a test where the intensity of coloring of the samples with sodium sulfide is compared with that of the control solution, it is necessary to confirm that heavy metal components can be detected fully in the process of test solution preparation. The Heavy Metals Limit Test in JP specifies four preparation methods for the test solutions. An appropriate method will be selected and used for further testing. The test method that gives the best recovery rate is to be adopted. The procedure is as follows ... 

Treat the three-level lead-spiked drug substance samples according to methods 1 to 4 to prepare the test solutions and the control solution. Separately, designate a solution prepared according to the same preparation method as the control solution. Using this control solution, determine the absorbance of the test solutions and calculate the recovery rate at each amount added. 

Precision (Repeatability). To evaluate the repeatability as specified in the quantitative method of heavy metals in the drug substance, the drug substance samples are treated according to the test solutions and the control solutions preparation method selected from methods 1 to 4 of Heavy Metals Limit Test in JP. Take five or six aliquot samples collected from a single lot of homogeneous drug substance and determine the quantity of heavy metal in each sample aliquot using the prepared test and control solutions. The data obtained are statistically analyzed. 

Prepare the test and control solutions from the aforementioned sample according to the method of test solutions selected and the control solutions preparation procedure specified in the limit test method in the Specifications and Testing Methods. Use these solutions to determine the quantity of heavy metal by the same calibration curve from the accuracy experiment. This procedure is repeated for each test solution. 

Detection Limit. The detection limit of heavy metals limit test method is obtained from the test solutions and the control solution. These solutions are prepared using one of methods 1 to 4 of the control solution preparation method. The detection limit is determined by visual inspection of a series of diluted standard lead solutions. 

How should the criteria for selections from methods 1 to 4 of the test be established, and the solution preparation specified in the heavy metals limit test in JP be controlled ... 

The master curves obtained from specimens cast from tetrahydro-furan solution at 2 and 4% strain, respectively, are slightly different. These differences, however, are probably within the experimental error. An idea of the reproducibility can be obtained from Figure 4, which shows the master curves of the creep compliances obtained on specimens cut from two sheets of Kraton 102 cast from benzene solution. Although the method of preparation appeared to be identical, there are noticeable differences between the two curves. Even larger differences exist between these curves and the master curve obtained from the relaxation data after conversion to creep. Again, there were no apparent differences in the method of preparation of the sheets from which the specimens for the relaxation and creep tests were cut. 

In addition to solubility properties, the stability of the liquor during preparation and use (i.e., the solution stability) is important. For reactive dyes the solution stability in the presence of electrolytes is important (see Test Methods ISO 105-Z07-Z09). For disperse dyes the dispersion properties are of similar importance, but they are not easy to describe because of the complex processes and unstable dispersion states. Therefore, a large number of test methods exist, the results of which are usually limited in their application. A critical review can be found in [26],... 

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