Ausnützung der Sorptionseigenschaften von Trägern in der Graschromatographie

Zusammenfassung Die Möglichkeit der Anwendung fester Stoffe mit kleinen Oberflächen als Sorbentien in der Gaschromatographie wurde untersucht. Die Sorptionseigenschaften von Trägern auf Kieseiguhrbasis, Rysorb BLK, LM und P wurde geprüft. Rysorb BLK wurde mit Saccharose in verschiedener gewichtsmäßiger Bedeckung modifiziert und der Einfluß des Bedeckungsgrades auf die Trennwirkung des Trägers untersucht. Ferner wurde die analytische Anwendung solcher Träger bewertet.

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Summary The possibility of employing solid materials with small surfaces as sorbents in gas chromatography was investigated. The sorption properties of carriers with a kieselguhr base, Rysorb BLK, LM and P were tested. Rysorb BLK was modified with saccharose in various coatings by weight and the influence of the degree of coating on the separation action of the carrier was studied. An appraisal was also made of the analytical application of such carriers.

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Résumé On a étudié la possibilité d'utiliser des corps solides de petites surfaces comme sorbants en Chromatographie en phase gazeuse. On a expérimenté les propriétés de sorption des supports sur base de kieselguhr, de Rysorb BLK, LM et P. Le Rysorb BLK a été modifié avec le saccharose avec un revêtement différent et équivalent et Ton a étudié l'influence du degré de revêtement sur l'action séparatrice du support. On a apprécié de plus l'emploi de ces supports en analyse.

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Herrn Prof. Dr. Ing.M. Jureek zum 60. Geburtstag gewidmet.     

Catalytic flow-injection determination of copper at nanogram levels by using color formation of N-phenyl-p-phenylenediamine with m-phenylenediamine in the presence of pyridine and ammonia as activators

A spectrophotometric flow-injection method for determining copper(II) has been developed. It is based on the catalytic effect of copper(II) on the oxidative coupling of N-phenyl-p-phenylenediamine with m-phenylenediamine in the presence of hydrogen peroxide. Pyridine and ammonia as activators increased the absorbance for the copper(II)-catalyzed coloration, and the dye formed was stabilized by adding a non-ionic surfactant. The working range of the method was 0.1-2.0 ng ml(-1) of cooper(II) with a relative standard deviation 2.4% at a sampling rate of 30 h(-1). Interference from iron(III) was effectively suppressed by citric acid. Copper in natural water samples can be determined easily.     

Synthesis and properties of fluoronitroalcohols. Report 5. 1,5-difluoro-1,1,5,5-tetranitropentan-3-ol

Conclusions 1,5-Difluoro-1,1,5,5-tetranitropentan-3-ol was obtained by reduction of 1,5-difluoro-1,1,-5, 5-tetranitropentan-3-one with NaBH₄ in the presence of BF₃ etherate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 398–401, February, 1986.     

Reaction of 1-chloromethylisatin with indole

In the condensation of N-chloromethylisatin with indole and 2-methylindole in the presence of triethylamine, instead of the expected N-skatylisatins the products of their subsequent transformations with opening of the five-membered ring of isatin -o-(N-skatylamino)- and o[N-(2-methylskatyl)amino]benzoylcaproic acids —were isolated. In addition to the formation of these -keto acids, under the indicated conditions one observes dimerization of N-chloromethylisatin and N-chloromethyl-5-methylisatin to give 2-(1-isatinylmethyloxy-3H-indolin-3-one and 2-(5-methyl-1-isatinylmethyloxy)-5-methyl-3H-indolin-3-one, respectively, i.e., dimers containing isatin rings in lactam and lactim forms. The structures of the compounds were confirmed by IR, PMR, and mass-spectral data.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 217–220, February, 1977.     

Multiparametric curve fitting-I Computer-assisted evaluation of chelatometric titrations with metallochromic indicators

A curve-fitting procedure has been developed for the photometric complex-formation titration of the metal-indicator complex MIn(N) which is assumed to predominate in solution. By means of a least-squares procedure the following five parameters were determined: the end-point, the absorbance of the indicator complex A(M)XXX. the indicator concentration CXXX, the stability constants and, if possible, k(MY) . A modified version of Sillen's Letagrop Vrid has been used for the mathematical-statistical approach of the non-linear model based upon the non-transformed function A = f(v). Additional information is obtained about the goodness of fit, indicating whether the chosen model with predominance of MIn(N) is correct or not. The use of the program is demonstrated by application to chelatometric microtitrations of zinc and lead with EDTA, using Naphthylazoxine 6S and SNAZOXS as metallochromic indicators.     

Stereospecific total synthesis of (±)-strempeliopine

The 18-methylene-1,2-dehydroaspidospermidine (III) was stereospecifically transformed into the schizozygane alkaloid strempeliopine (II) in 16,6 % overall yield.     

Chemical structure of poly(ethylene terephthalate)–styrene and nylon–styrene graft copolymers prepared by radiation techniques

The graft copolymerizations of styrene onto poly(ethylene terephthalate) (PET) and nylon fibers were carried out by the mutual irradiation and preirradiation methods. True graft copolymers were isolated from the products by extraction and characterized by hydrolysis and osmometry. Among the swelling agents employed, methanol was most effective for increasing the extent of grafting onto PET. In both methods of the grafting, the molecular weight of polystyrene formed in the substrate matrix was higher than one million if no chain-transfer agent was added to the monomer solution. Similar to the case of radiation grafting onto poly(vinyl alcohol) and cellulose, the isolated graft copolymer carried only one branch per copolymer molecule in both cases. Of great interest is the particularly low extent of grafting in the case of PET–styrene. This should be attributed to the low sensitivity of PET to radiation. The grafting site on the mother polymer molecule is discussed on the basis of the solution behavior of the branch polymers separated from the backbone.