Dilution determine test sensitivity

The results of endotoxin tests for in-process solutions, bulk materials, and finished parenteral products should be reported in the same units as those assigned to the product. Two factors determine the sensitivity of a BET. For infusion solutions and device extracts, the gel-clot sensitivity or the lowest point on the standard curve (lambda for kinetic LAL) and the amount of dilution determine test sensitivity.For products that have an endotoxin limit in EU/mg, the choice of lambda and the concentration of the test material determine sensitivity. The formula for product-specific sensitivity (PSS) is a convenient way to calculate the sensitivity of a BET for this type of product, where ... 

For a different reaction, use a drop of a noxious stimulus such as ammonium hydroxide, potassium permanganate, or chloroform. Test dilutions in steps of 1/10, 1/100, 1/1,000, etc. to determine the sensitivity of the animals (Hainsworth 1967). 

Repeat application patch tests in which diluted materials are applied to the same site each day for 15-21 days have been reported using several species (the guinea pig or rabbit being most commonly used) (Phillips et al. 1972). Because the degree of occlusion is an important determinant of percutaneous penetration, the choice of covering materials may determine the sensitivity of a given test (Mag-nusson and Hersle 1965). A reference material of... 

A.4.3.2.1 Where the mixture itself has not been tested to determine its sensitizing properties, but there are sufficient data on both the individual ingredients and similar tested mixtures to adequately characterize the hazards of the mixture, these data will be used in accordance with the following agreed bridging principles as found in paragr h A.0.5 of this Appendix Dilution, Batching, Concentration of mixtures, Interpolation, Substantially similar mixtures, and Aerosols. 

The authors observed that this gave sensitivities of 24/53 in those previously exposed to SM compared to 1/249 in those who had not been exposed before. Those who reacted in these tests were retested with solutions of SM in benzene at different dilutions to determine how sensitive they were. " The authors concluded that the sensitive individuals at Porton Station were up to 1000 times more sensitive than normal subjects. The numbers used in this study were small—four and six compared to a control group of nine—but they stimulated further work to define the potency of SM. 

Qualitative. The classic method for the quaUtative determination of silver ia solution is precipitation as silver chloride with dilute nitric acid and chloride ion. The silver chloride can be differentiated from lead or mercurous chlorides, which also may precipitate, by the fact that lead chloride is soluble ia hot water but not ia ammonium hydroxide, whereas mercurous chloride turns black ia ammonium hydroxide. Silver chloride dissolves ia ammonium hydroxide because of the formation of soluble silver—ammonia complexes. A number of selective spot tests (24) iaclude reactions with /)-dimethy1amino-henz1idenerhodanine, ceric ammonium nitrate, or bromopyrogaHol red [16574-43-9]. Silver is detected by x-ray fluorescence and arc-emission spectrometry. Two sensitive arc-emission lines for silver occur at 328.1 and 338.3 nm. 

Alkalinity and Lime.—These are determined as in defecated juice, but for the alkalinity only 20-25 c.c. of juice are taken, and this is then diluted sufficiently to give a slightly coloured liquid. If the juice is so highly coloured that the change of colour with phenolphthalein cannot be detected with certainty, sensitive litmus paper is used and a drop of the liquid removed and tested from time to time during the titration. 

Thus far, quality objectives for chemical substances are derived from the most sensitive organisms in acute and chronic toxicity test batteries that determine NOEC values for different trophic levels. The pT-method similarly determines specific sample dilution levels that are devoid of adverse effects toward (micro)organisms of a standardized test battery. Common to both approaches is the more frequent use of water-column test organisms as opposed to benthic-dwelling organism that reflect more intimate contact with sediment. This practice is primarily based on the fact that standardized bioassays capable of appraising sediment porewaters and elutriates are presently more numerous than solid-phase tests for whole-sediment assessment. As more of these latter tests become developed and standardized (see Chapters 12 and 13, volume 1 of this book on amphipod and chironomid tests), their more frequent use will contribute to a better understand of the toxic effects of sediment-bound contaminants. 

The standard measurement procedure for odor determination (VDI, 1994) is called olfactometry. It uses the human olfactory sense (Gostelow et al, 2001) for the determination of odor qualities. The human nose is an extremely sensitive odor detector and is used in subjective and objective sensory measurements. The latter expresses the strength of odor in terms of the number of dilutions of odor-free air required to reduce the sample odor to threshold concentration (Gostelow et al, 2001). The threshold concentration is reached when the human nose can just smell the odorous substance. Because every nose has different sensitivity, the standard test procedure involves four people at the same time. Prior to olfactory... 

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