Substances, xiii

As a rather strongly hydrophilic anion, nitrate requires an ISE membrane containing a strongly hydrophobic cation, as described on p. 169. This function was fulfilled in the first nitrate electrode from Orion Research by cation V [180] in nitro-p-cymene 5. The electrode can be used in the pH range 4-7. In other commercial electrodes, the ion-exchanger ion is a tetra-alkylammonium salt, for example in the electrode from Coming Co., substance XIII in solvent 6 [27]. An ISE with a renewable membrane surface was found to be very useful (see section 4.1 and fig. 4.4), in which the ion-exchanger solution contains the nitrate of crystal violet VII dissolved in nitrobenzene [191]. The NOj ISE also responds to nitrites that can be removed by addition of aminosulphonic acid. 

The serological properties of simple substances, XIII. The reactions of antiserum homologous to the p-azosuccinanilate ion group. J. Am. Chem. Soc. 70 (1948) 1352-1358. (David Pressman, John H. Bryden, and Linus Pauling). 

The following values were obtained (Xni)— 36.9%, (XIII-GA 1 1)— 55.8%, (XIII-GA 1 2)—55.9%, (Xm-GA 1 3)—54.7% and (XIII-GA 1 4)— 65.5%. The elathrates of the compositions (XIII-GA 1 1), (XIII-GA 1 2) and (XIII-GA 1 3) showed the same activity, which was approximately 1.5 times higher than the activity of the pure compound (XIII), whereas the clathrate of compound (XIII-GA 1 4) was 1.77 times more active than substance (XIII). The correlation coefficient between the calculated estimate TTRank and the experimental value amounted to i =0.965. 

The American authors suggested (X) or (XI), already considered by Spath and Nikawitz for vasicine, and support for a formula of type (XI) was provided by Spath, Kuffner and Platzer, who, by condensing o-nitrobenzyl chloride with methyl y-aminobutyrate to o-nitrobenzyl-pyrrolidone (XII), reduction of this to the amino-compound (XII NOa —> NHj) and ring-closure in presence of phosphoryl chloride obtained the base d -pegene (XIII), m.p. 99-100°, identical with the product formed by the reduction of deoxychloropeganine. The same substance... 

If the substance shared between two solvents can exist in different molecular states in them, the simple distribution law is no longer valid. The experiments of Berthelot and Jungfleiscli, and the thermodynamic deduction show, however, that the distribution law holds for each molecular state separately. Thus, if benzoic acid is shared between water and benzene, the partition coefficient is not constant for all concentrations, but diminishes with increasing concentration in the aqueous layer. This is a consequence of the existence of the acid in benzene chiefly as double molecules (C6H5COOH)2, and if the amount of unpolymerised acid is calculated by the law of mass action (see Chapter XIII.) it is found to be in a constant ratio to that in the aqueous layer, independently of the concentration (cf. Nernst, Theoretical Chemistry, 2nd Eng. trans., 486 Die Verteilnngssatz, W. Hertz, Ahrens h annulling, Stuttgart, 1909). 

The quantitative comparison of measured. To values and 5 values calculated for models A for mesitylene and hexamethylbenzene is given in Tables XII and XIII. With omission of the innermost maximum and minimum, the unreliable third minimum, and the very weak fifth maximum for each substance, the average values sa/s0 = 1.000 and 1.002, respectively, are found. These correspond to the interatomic distances C — = 1.54 0.01 A. and Car-Car = 1.39 A. in both substances, the 0 —Qa distance being equal to the single-bond distance in aliphatic compounds and the Car—distance to that in benzene to within the probable error of the determination. 

Table XIII.—Transfer Constants for Various Substances with Styrene ...

The tests for microbial limits and recommendations for microbial quality criteria of raw materials, excipients, drug substances, and pharmaceutical products have been established in pharmacopoeial compendia for over 30 years. These tests are listed in the USP 24 Chapter (61) Microbial Limits Tests and in the Ph. Eur. 3rd ed.. Biological Tests 2.6.12 and 2.6.13, Microbial Contamination of Products Not Required to Comply with the Test for Sterility (total viable count, tests for specified microorganisms) and the JP XIII 30 Microbial Limit Test. 

However, these synthetic procedures were useful only in the preparation of primary a-acetoxymethyl alkylnitrosamines and a-chloromethyl alkylnitrosamines. The cleavage of secondary ethers, such as XIII with acetic anhydride or acetyl chloride was so vigorous that no characterizable substances could be isolated. In view of this problem, we looked for another synthetic route which would allow the isolation of secondary derivatives. The first experiment tried, namely that of nitrosyl chloride with N-methylene t-butylamine at -30° was successful. The addition of NOCl at this temperature... 

A further concern is the limited range of substances that will be subject to authorization. The criteria for PBT and vPvB substances (set out in Annex XIII) are very restrictive and will be met by very few substances. For substances of equivalent concern , such as endocrine disrupters, there must be scientific evidence of probable serious effects to human health or the environment . This is a demanding requirement and it could therefore be the case that no substances become subject to authorization because they are endocrine disrupting. The number of substances that will be subject to authorization will also depend on the capacity of the European Chemicals Agency to deal with the applications. 

Many aspects of REACH are to be reviewed within a few years of REACH coming into force in June 2007- These include Annex I, which sets out the requirements for CSRs (to be reviewed within 12 months) Annex XIII (criteria for identification of PBT and vPvB substances) (within 18 months) the authorization of endocrine-disrupting substances (after 6 years) and the registration requirements for substances below 10 tonnes (after 12 years). These reviews, along with the fact that the implementation of REACH will depend on how its provisions are interpreted and the guidance documents that are produced, mean that it is very difficult to say what REACH will mean in practice for the production and use of synthetic chemicals and the protection of human health and the environment from their harmful effects. 

In Wright s opinion the existence of the transient compound,(XIII) is proved by the formation of substance (IX) which can be isolated from the products when cyclonite undergoes nitrolysis of the P and R bonds. 

All the naphthylpyrroles (14-17) are crystalline substances (see Table XIII) soluble in diethyl ether, acetone, chloroform, DMSO, poorly soluble in ethanol, hexane, and insoluble in water. Typical H-NMR spectra of these pyrroles are presented in Table XVI. 

In Metaphysics XIII 3, Aristode says that mathematicians study sensible material substances but in their study ignore or abstract away their physical aspect. 

Yentsch, C., and Phinney, D. (1997) Yellow substances in the coastal waters of the Gulf of Maine Implications for ocean color algorithms. In Ocean Optics XIII (Ackleson, S.G., ed.), pp. 120-131, SPIE Proceedings 2963. 

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