P test

With some acids (e.g., succinic acid and sulplianilic acid) more satisfactory results are obtained by reversing the order of mixing, i.e., by adding the solution of the so um salt of the acid to the reagent. It should be pointed out that the melting points of the derivatives as determined on the electric hot plate (Fig. II, 11, 1) may differ by 2-3° from those obtained by the capillary tube method. In view of the proximity of the melting points of the derivatives of many acids, the mixed m.p. test (Section 1,17) should be applied. 

The hydrolysis by alkali is illustrated by the following experimental details for benzamido. Place 3 g. of benzamide and 50 ml. of 10 per cent, sodium hydroxide solution in a 150 ml. conical or round-bottomed flask equipped with a reflux condenser. Boil the mixture gently for 30 minutes ammonia is freely evolved. Detach the condenser and continue the boiling in the open flask for 3-4 minutes to expel the residual ammonia. Cool the solution in ice, and add concentrated hydrochloric acid until the mixture is strongly acidic benzoic acid separates immediately. Leave the mixture in ice until cold, filter at the pump, wash with a little cold water and drain well. RecrystaUise the benzoic acid from hot water. Determine the m.p., and confirm its identity by a mixed m.p. test. 

Alkalinity and Lime Content. Alkalinity is the ability of a solution or mixture to react with an acid. The phenolphthalein alkalinity refers to the amount of acid required to reduce the pH to 8.3, the phenolphthalein endpoint. The phenolphthalein alkalinity of the mud and mud filtrate is called the and Pp respectively. The P. test includes the effect of only dissolved bases and salts while the P test includes the effect of both dissolved and suspended bases and salts. The methyl orange alkalinity refers to the amount of acid required to reduce the pH to 4.3, the methyl orange endpoint. The methyl orange alkalinity of the mud and mud filtrate is called the and Mp respectively. The API diagnostic tests include the determination of P, Pp and Mp All values are reported in cubic centimeters of 0.02 N (normality = 0.02) sulfuric acid per cubic centimeter of sample. 

The Pf and P test results indicate the reserve alkalinity of the suspended solids. As the [OH"] in solution is reduced, the lime and limestone suspended in the mud will go into solution and tend to stabilize the pH. This reserve alkalinity generally is expressed as an equivalent lime concentration, in Ib/bbl of mud. 

Hudson, J. C. and Acock, G. P., Tests on the Corrosion of Buried Iron and Steel Pipes, Iron and Steel Inst. Special Report No. 45 (1953)... 

An eye should also be kept on the absolute size of the standard deviation before and after a proposed elimination. If the elimination of a questionable point results in a standard deviation that is markedly smaller than what is common experience for the test at hand, the P-test cannot be used for confirmation, unless S2 is replaced by either the method obtained during the validation, or its lower confidence limit. 

The Delvotest-P-Multitest is a modification of the original Delvotest-P test (50). This is not an ampoule test but a polystyrene plate-based test with cups similar in principle to the original version. Its main advantage is that it permits up to 96 test cups to be used at one time. Following a collaborative study (51), both tests have been adopted by the Association of Official Analytical Chemists (AOAC) as official tests for the detection of -lactams in milk and milk products. 

The Delvotest-P test (84), which was originally designed for rapid detection of penicillins in milk, has also been successfully employed for the detection of oxytetracycline residues in chicken tissues. In this method samples of liver, kidney, and muscle tissue are homogenized with distilled water, and the homogenates... 

A number of B.P. tests require derivatization of the substance under investigation before the UV absorbance is recorded. In these cases, in order to take account of the possibility of the reaction not proceeding to completion, the comparative method is employed, which makes use of a reference (defined in the B.P.). The concentrations and absorbances of the reference and substance under investigation are related by equation (2.5) ... 

Use of this P test (or F test) procedure to judge the value of added parameters in fitting experimental data with a model is strongly encouraged, and it can be employed in a number of experiments in this book. For example, in Exps. 37 and 38 the possible... 

Hansen, N. K., and Coppens, P. Testing aspherical atom refinements on small-molecule datasets. Acta Cryst. A34, 909-921 (1978). 

Casadesiis, R., Moreno, M., Gonzalez-Lafont, A., Lluch, J.M., and Repasky, M.P., Testing electronic structure methods for describing intermolecular H- H interactions in supramolecu-lar chemistry, J. Comput. Chem., 25, 99-105 (2004). 

Ibogaine did not mimic the analgesic action of morphine in either the tail flick (1-40 mg/kg, i.p.) or hot plate (up to 20 mg/kg, i.p.) tests, although it exhibited analgesic activity in the phenylquinone writhing test (ED50 9.7 mg/... 

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