Dilution test

Whereas these preparations do not possess the high bacteriostatic activity of quaternary ammonium germicides, they have the alternate advantage of being rapidly functional in acid solution. In comparative experiments of several different disinfectants, the acid—anionic killed bacteria at lower concentration than five other disinfectants. Only sodium hypochlorite and an iodine product were effective at higher dilution than the acid—anionic. By the AO AC use dilution test, the acid—anionic killed Pseudomonas aeruginosa at 225 ppm. Salmonella choleraesuis at 175 ppm, and Staphylococcus aureus at 325 ppm (172). 

Both the liquid and the solid dilution tests described above for bacteria (sections 3.6.1 and 3.6.4) may be used suitable media must, of course, be employed. 

Comparison of Effectiveness Tests. Three laboratory methods were compared the revised standard dispersant effectiveness test used and required for regulation in the United States, the swirling flask test (developed by Environment Canada), and the IFP-dilution test (used in France and other European countries) [1693]. Six test oils and three dispersants were evaluated. It was concluded that the three tests gave similar precision results, but that the swirling flask test was fastest, cheapest, simplest, and required the least operator skill. 

Arctic Conditions. The effectiveness of relevant dispersants for use under arctic conditions has been tested with a dilution test [235,236]. Arctic conditions mean a low temperature of 0° C and water salinities of 0.5% to... 

Aliquots of water used for dilution are taken from plastic bucket and divided into other plastic buckets. A portion of the water is poured into the plastic bags containing the test materials. After thorough agitation, the concentrated test substance solution is poured into the plastic bucket and the plastic bag is rinsed twice with the rest of the water. After thorough agitation, the diluted test solution in the bucket is poured into the application equipment. 

Bioassay with mosquito larvae for the detection of insecticide residues in fresh and processed fruits and vegetables is feasible, subject to the limitation that the untreated natural product is in itself nontoxic to the larvae at the dilutions tested. 

Phase dilution test Place two emulsion droplets on a glass slide and add a droplet of one component to each emulsion droplet, stir, and observe under a microscope. This test is based on the principle that an emulsion can only be diluted with the liquid that constitutes the continuous phase. 

A series of antibody dilution tests prior to the combined ISH/ IHC can give a good hint of optimal antibody dilution. Best fluorescence images are obtained when the intensity of the individual fluorophores are balanced. 

Set up a graph of RI on the abscissa versus dilution number on the ordinate and draw a horizontal line that extends from the start of an odor to its stop for each dilution tested. Drop a perpendicular at the beginning or end of an area of the graph where no odor was detected to define the odor-active regions in the chromatogram. 

Dilution tests should be performed for a drug-surfactant solution to determine whether precipitation of the drug occurs on dilution. Readers can refer to the Chapter 9 Solubilization Using Cosolvent Approach for the dilution test methods. 

Norn, M.S. 1965. Tear secretion in normal eyes. Estimated by a new method The lacrimal streak dilution test. Acta Ophthalmol (Copenh) 43 567. 

Laboratory QC data are classified as batch QC data and individual sample QC data. For all types of analysis, batch QC data originate from laboratory blanks, laboratory control samples, matrix spikes, and laboratory duplicates. Individual sample QC data in organic compound analysis are obtained from surrogate and internal standard recoveries. Matrix interference detection techniques (serial dilution tests, postdigestion spike additions, and MSA tests) are the source for individual sample QC checks in trace element analysis. (Chapter 4.4.4.5 addresses the trace element matrix interference detection techniques and the associated acceptance criteria.)... 

The Diluent, Mobile Phase, Test Solution, and Chromatographic system used for this test method are the same as those described for the Limit determination of 5-benzyl-3, 6-dioxo-2-piperazineacetic acid. The procedure requires a Diluted Test Solution, which is prepared by pipetting 2.0 mL of the Test Solution into a 100-mL volumetric flask, diluting to volume with Diluent, and mixing. 

To Test Prints. Take 125.0ml of distilled water in a clear glass and add 1.0ml of the test solution. Pour 15.0ml of the diluted solution into a clear 30-ml glass container. Take six 4 X 5" prints or equivalent from the wash water and allow them to drip for 30 seconds into the 15.0ml of the dilute test solution. If a small quantity of hypo is present, the violet color will turn orange in about 30 seconds and become colorless in 1 minute. The prints should be returned to the wash and allowed to remain until further tests produce no change in the violet color. 

Suppose that with 10 jiL of an appropriately diluted test solution an absorbance decrease of 0.120 per minute is obtained in an assay in the same conditions and with the same substrate suspension. If the potency of the standard is assigned to be 38 FXP. unitsfyg, the absorbance decrease per minute corresponds to 38 x 0.911 = 34.62 FXP. units in a volume of 10 pL. For the... 

Examination of the root apex showed much the same effects as reported above (Fig. 15.6a-d). The calyptra was a particularly sensitive tissue, showing dramatic mitochondrial swelling at all dilutions tested (Fig. 15.6b-d). A conspicuous effect of the treatment with the RO fraction on the root apex was the inhibition of amyloplast development as statoliths in the columella cells of the calyptra (Fig. 15.6b-c). The almost complete lack of starch and of lipid-associated microbodies in... 

All these aspects have been recently studied in two publications (10.13). which standardized the dilution test for pungency and clearly established correlations with the estimates of total, and even individual, capsaicinoids. These papers also review the earlier attempts at standardisation. Two approaches are possible use of a fairly homogenous panel to determine the threshold pungency response due to the stimuli or use of a general panel to determine the average threshold of the panel for the stimuli. The second value will have wider applicability in use situations but the first value should be useful for correlative work. The two methods approach one another when panels are screened and trained to avoid all bias factors, and when carefully planned dilution levels, details of panel procedure, treatment of data, and expression of results are adopted. In fact, the results published in the two independent studies (10.13). show close values, 17+0.9 million for natural capsaicinoids and 16.1+0.6 million for pure capsaicin and dihydrocapsaicin. 

---