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Summary Pesticides may be detected following thin-layer chromatography by spraying the chromatogram with a reagent which forms a-complex with the pesticide. The effect of various pesticide structures and substituents in choosing a suitable-complexing reagent is discussed, as well as the effect of these factors in influencing the colour of the complex formed. Quantitative analyses may be performedin situ on the thin-layer chromatogram and positive identification of the-complexed compounds may be made by mass spectrometry. The procedure should be applicable for formulation analysis or studies of pesticide decomposition.
Issued as NRCC No. 13120. 相似文献
Zusammenfassung Zum Nachweis von Pestiziden besprüht man deren Dünnschichtchromatogramme (DC) mit einem zur Bildung eines-Komplexes geeigneten Reagens. Die Bedeutung verschiedener Pestizidstrukturen und -Substituenten bei der Wahl eines solchen Reagens wurde erörtert; ebenso der Einfluß der genannten Faktoren auf die Farbe des Komplexes. Quantitative Bestimmungen lassen sich unmittelbar auf dem DC, Nachweise der einzelnen komplexierten Verbindungen mit Hilfe der Massenspektrometrie durchführen. Das Verfahren eignet sich zur Strukturanalyse sowie zur Untersuchung von Pestizidabbauproblemen.
Issued as NRCC No. 13120. 相似文献
4.
Summary A method is described for the rapid determination of traces of copper in the ppm range in cobalt and nickel salts. The % standard deviation for the analysis is reported as 3.4 to 3.7 for aequous solutions and 4.8 to 5.0 for carbon tetrachloride sprayed directly into the flame after extraction.
Zusammenfassung Ein Verfahren zur raschen Bestimmung von Kupferspuren im ppm-Bereich in Kobalt- und Nickelsalzen wurde beschrieben. Die Standardabweichung in wäßrigen Lösungen beträgt 3,4 bis 3,7%, bei unmittelbarem Versprühen der Tetrachlorkohlenstoffextrakte in die Flamme 4,8 bis 5,0%.相似文献
5.
M Schreurs G W Somsen C Gooijer N H Velthorst R W Frei 《Journal of chromatography. A》1989,482(2):351-359
Dynamic quenching of Eu(III) and Tb(III) luminescence by inorganic anions as a detection method in ion chromatography was investigated. To obtain a high luminescence intensity, lanthanide(III) complexes are formed with ligands which make indirect excitation of the ions possible. Only a few anions (e.g., nitrite, chromate) induce efficient dynamic luminescence quenching. Chromate is an efficient quencher of Tb-acac luminescence. Samples of tap water and surface water, spiked with chromate, were injected into a high-performance liquid chromatographic system with post-column addition of the luminescent complex. In this way, a detection limit of 1.1 . 10(-7) M (13 ppb) of chromate could be obtained. 相似文献
6.
Zusammenfassung Aus potentiometrischen Daten wurde die Konstante der Entstehungsgeschwindigkeit des Zinktartrates bei 18° berechnet. Ihr durchschnittlicher Wert beträgt 1,3·102 mol·min–1 und der Wert der Zerfallsgeschwindigkeitskonstante beläuft sich im Durchschnitt auf 7,5·10–2 mol·min–1. 相似文献
7.
Summary In this study a new approach is presented for on-line radiometric detection in reversed phase LC of medium to low polarity
compounds labelled with14C.
The test compounds,14C-carbaryl and14C-parathion, are extracted post-column into a non-water miscible liquid scintillation cocktail. The segmented two-phase system
formed is introduced into the beta-detector without phase separation and collected in a capillary storage tube.
After completion of the LC separation and detection process, the direction of the flow in the storage system is reversed and
the segmented contents of the loop led at lower flow-rates through the beta-detector again. An enhanced signal, corresponding
to the increase in counting time is obtained without measurable peak broadening.
The lowest possible detection limit of the system is 9 counts per peak corresponding to subnanogram quantities of tested pesticides.
Calibration curves are linear over at least 2 orders of magnitude and have the expected theoretical slopes.
The reproducibility of the system is better than 4 % rel. S.D. An application to a recovery study of parathion shows the practical
potential of this technique.
Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984 相似文献
8.
Klaus Müllen Siglinde Bender Eleni Kotzamani Hans Schmickler Bruno Frei Hans R. Wolf 《Tetrahedron letters》1981,22(36):3513-3516
The conformational mobility of a series of conjugated dienones is investigated by low-temperature NMR- and IR-spectroscopy and interpreted in terms of substituent effects. 相似文献
9.
The amperometric behaviour of a copper electrode towards amino acids is studied by means of a rotating disc electrode. A theoretical model describing the anodic background current in a buffer solution and the increase of the current caused by amino acids is checked experimentally. The influences of the amino acid concentration, the rotation speed of the electrode and the composition of the buffer solution are studied. It is proved that chemical dissolution of a passivating film on the electrode surface, which is enhanced by the complexation reaction between the amino acid and copper(II) ions, is the principle of the phenomena observed. The applicability to flow systems is demonstrated. 相似文献
10.
Summary The use of non-segmented flow, post-column reaction detection is evaluated for use with miniaturized HPLC. Non-segmented open-tubular reactors with internal diameters 0.1 mm to 0.25 mm and packed-bed reactors with internal diameters of 1 mm, filled with 5 and 10 m particles are evaluated theoretically and experimentally with respect to band broadening and pressure drop characteristics. An integrated system consisting of miniaturized HPLC (1 mm i. d.) columns and compatible hardware is described. An example of the separation of catecholamines is given. 相似文献