DE2226994A1 - Identification of n cpds in chromatographs - by fluorescence using a single reagent - Google Patents

Abstract

N base cpds. are identified by the formation of a cpd. of the N base cpd. to be identified with solid Cu(I) halide or Cu-pseudo halide as reagent, which is made to fluorescence in UV light. Absorbing agents used in chromatography or electrophoresis may be impregnated or mixed with Cu(I) halide, pref. a soln. of CuI, or test paper or foil contg. Cu(I) cpds. which are suitable for spot tests may be used. For testing gaseous, or volatile N base cpds. or for the prepn. of contact copies of chromatograms which are evaluated by fluorescence, the single component exhibiting different colours at normal and lower temps.

Description

P A T E N T S C H R I F T submitted to the German Patent Office, Munich on from 1) Prof. Dr. H. D. H a r d t, 66) Saarbrücken 6, Hohe Wacht 22 (plus authorized recipient) 2) Graduate chemist H. G o h n i z d j a n i, 66) Saarbrücken 3, Kantstrasse 17 3) A. P i e r r e, 665) Homburg / Saar, Wirthstr. 4 concerning: method of analytical Identification of nitrogen compounds by fluorescence and fluorescence thermochromism.

1) Areas of application: chemical analysis, especially for use as reagent paper, in paper chromatography.

Thin layer chromatography, column chromatography, gas chromatography and gas test tubes, electrophoresis and in connection with molecular sieves.

2) Purpose: The mentioned analytical separation processes often require an additional and final identification of the isolated components and - e.g. B. in chromatography - an indexing of the separated substances. These must as far as they are colorless themselves, made visible by spraying on a Roagenze will. In a similar way, chromatograms with radioactive substances can be radiometric measured or those with fluorescent or phosphorescent components evaluate in the ultraviolet light.

3) State of the art: In analytical chromatography, sometimes the possibility of indexing or identifying the separated substances made use of the fact that one sprayed fluorescent indicators or put them in incorporates the sorbent material. 1) Also the extinction of fluorescence in one appropriately prepared carrier by the chromatographic Stains is used here. 2) 4) Criticism of the state of the art: However, as far as substances which in themselves do not fluoresce in the dissolved state or in the molecular state the chromatographic carrier (sorbent) after separation to fluoresce or phosphorescence are to be brought about, you need a large number of them different reagents that have to be "tried" one after the other. 3) to 7) When entering the detection of the chromatographic spots is based on the fact that the severed Sotffe strongly delete a @@@ eszenz originated by the wearer, is one Luminous component (e.g. zinc cadmium sulfide) suitable for the detection of vek @ erers Substances of different chemical composition The verification is then natural much less explicable.

The @@ n @ nen a "fluorescence thermochromism" was also @ el @ ng unknown and has not yet been used for the stated purpose.

5) Task W becomes @ in contrast to and possibly in addition to the pictures ngen methods - a method proposed which E ubt with only one reagent a multitude of chemical components of the lowest concentration fluorimetrically @ but to what to and individual chemical compounds immwer 1b of this group under certain circumstances additionally to be characterized by the fluorescent color, especially if this proves to be temperature-dependent.

(Fluorescence thermochromism 6) Solution: Kopfer (I) halides and copper (I) pseudohalides react with many, especially aromatic nitrogen bases, to form compounds different compositions, such as CuXaL, CuX.La or CuX.L3. (X = Cl, Br #, JI, CN, SCN; L = e.g. a pyridine base).

According to our observations, these compounds fluoresce in the ultra-violet Light and let themselves mostly also through their fluorescent color, differ qualitatively. Table 1 gives an overview of this.

The fluorescence is due to the existence of the corresponding solid copper (I) compound Bound9 therefore expires in the event of dissolution or chemical destruction, as well as in the event of thermal Decomposition, which occurs, for example, in methylpyridine complexes between 30 and 800 begins, but can also be extremely high9, for example, in the case of complex of copper (I) iodide with nicotinic acid amide, which only decomposes at 1500.

for the proposed methods of identification and indexing of nitrogen bases due to those in contact with solid copper (I) halides, etc. mostly occurring fluorescence is however the phenomenon of §'Fluoreszenz-Thermochromie " 10) of particular importance.

Many of the nitrogen bases investigated so far have copper (I) compounds of the type CuX.L, whose fluorescent color changes at the temperature of the liquid Nitrogen and often reversible into a different light emission at less low temperatures converts For example, the compounds CuCl. (4-aminopyridine) and CuCl. (3-aminopyridine), both of which fluoresce yellow at room temperature, thereby distinguish that, after cooling to about -180 °, the former remains yellow, the latter, however, fluoresces bright blue. (Table 2) Albeit some connections the composition CuX.Ln and CuX.L because of possible oxidation to copper (II) compounds do not have sufficient shelf life for preparative use, is suitable their short-term presentation for analytical purposes.

For example, a paper impregnated with copper (I) -joidid begins, in contact with gaseous aliphatic amines (e.g. methylamine, dimethylamine, Trimethylamine, and even ammonia) to instantly fluoresce pink, orange, or yellow, and this fluorescent color appears when the reagent paper is immersed in liquid Nitrogen (or in liquid air!) Immediately turns bright red. k more examples in table 3).

L = 3-amonopyridine CuX.L3 CuX.L X = Br yellow no fluorescence X = J no fluorescence yellow L = 4-aminopyridine CuX.L3 CuX.L X = Br green pink X = J blue pink Table 1: Examples for differentiating between different solvate cases the fluorescent color.

Fluorescent color compounds for type CuX.L 200-180 ° L = 3-aminopyridine: X = Br no F1. yellow L = 4-aminopyridine: X = C1 yellow blue X = Br pink blue X = J pink blue L = 2-ethylpyridine: X = J yellow blue L = 3-ethylpyridine: X = J yellow - pink - blue L = hexyl nicotinate X = J yellow blue Table 2: Examples for Fluorescence thermochromism of copper (1) compounds.

Table 3: Fluorescent colors of copper (I) iodide paper in contact with: at 200 at -1800 ammonia orange red methylamine pink red dimethylamine orange red trimethylamine yellow red diethylamine orange blue-violetb triethylamine no bottle red isopropylamine no bottle deep red aniline (benzene solution) orange red-violet urotropine (Methanol solution) orange red-violet nicotine (üenzoll solution) brick red blue-green pyrazole (Benzene solution) orange deep red 1,4-diazybicyclo (2,2,2) octane (benzene solution) deep yellow pink pyridine (gas phase) yellow orange-red skin violet piperidine (gas phase) yellow red-orange Morpholine (gas phase) orange red °) After prior heating of the reagent paper to to the disappearance of the initial green fluorescence.

7) Achievable Benefits: It can be achieved by simply contacting one solid copper (I) halide or pseudohalide with a nitrogen base in gaseous, liquid or dissolved form currently represented a fluorescent compound and thus a simplified indexing of chromatograms and Identification of nitrogen bases possible.

In addition, many of these compounds exhibit one on the carrier different fluorescence at low temperatures, so that in this way a additional information is obtained which is used to characterize the relevant Substance can serve.

The method is particularly practical when the copper (I) halide, preferably copper (I) iodide, is handled as a test paper or foil.

Spot reactions to the presence of nitrogen bases can be observed do the same by making a solution of cuprous iodide in acetonitrile (or solutions from Halogenocupratsi) in the presence of stabilizing additives such as hydrazine hydrate etc.) drips onto the substance to be examined. For example, while a tablet is standing there If pure acetylsalicylic acid does not show any fluorescence, this occurs in all Usually, as soon as similar preparations contain an addition of caffeine, of pyrazolone derivatives or similar contain.

8) Practical execution of the procedure: The procedure should, accordingly Sections 5) and 6) can be used in practice by a) reagent papers, the copper (I) iodide or similar. contain, be produced, these are intended to be used - to spot reactions to liquid or dissolved nitrogen bases, whereby many different solvates such as CuX.L and CuX.L3 by paper chromatography disconnect and use this to identify a particular connection - to make contact copies of other (e.g. paper or thin-layer) chromatograms and to characterize the stains taken over by their fluorescence.

- to spot reactions in which the liquid or dissolved sample is applied in strips and because of a copper concentration gradient (I) different solvates with different fluorescent colors are formed in the test paper - for the qualitative testing of gases and vapors for the presence of Nitrogen bases which form a fluorescent compound with copper halides.

b) reagent foils, for example aluminum foils, with a suitable Sorbent coated, made with copper (l) halide impregnation and how the test papers are used, or directly for chromatography or electrophoresis serve, c) sorbents such. B. silica gel, alumina hydrate, cellulose, magnesium oxide and the like be impregnated with a copper (I) halide solution or a copper (I) halide deposited by a chemical reaction on the surface of the adsorbent material d) reagent solutions are produced which contain copper (l) halides or pseudohalides, possibly with the addition of a stabilizing reducing agent, or in the make contact with the sample to be examined. Such solutions should, except for Purposes of spot reactions, for the development of chromatography of all kinds or for Production of materials according to 7 a - c) are used.

The above-mentioned impregnation with e.g. 13. Copper (I) iodide can be done in the simplest way with a solution of copper (I) iodide in acetonitrile, or in that the halide is formed on the support by the decomposition of a halogenocuprate (I), 8) by the reaction of copper (II) with iodide or by the reaction of iodine and acetone in the presence of copper (II) in the non-aqueous System according to Hardt and Bollig.

Claims (1)

Claims Method for the analytical identification of nitrogen compounds by 'luorescence and fluorescence thermochromism, 1. characterized in that a compound of the nitrogen compound to be characterized with solid copper (I) halide or -p.seudohalide is formed as a reagent and a matter of fact compound in the ultraviolet Light fluoresces and also often has a characteristic fluorescence thermom, chromia can be observed, further characterized in that 2. one of the usual Sorbents for chromatographic and electrophoretic purposes with copper (IJ-halides or pseudohalides, preferably impregnated with iodide or mixed with copper and 3. reagent papers and foils are used in the same way that Contain copper I3 connections and are suitable for execution according to claim (1) of spot reactions, for testing for gaseous or vaporized nitrogen bases or for the production of contact copies of chromatograms, which are then fluorimetrically can be evaluated, and 4. that the films mentioned, provided they have a Concentration gradient of copper (I) obtained for additional identification of nitrogen bases are suitable by adding several different fluorescent colors to a single component can show at normal and low temperature. The method is finally characterized in that 5. the fluorescent or fluorescence thermochromic Copper (I) compound also with a solution of a copper (I) halide or pseudohalide (e.g. CuJ ind CH3CN) can be formed and such a solution not only for production the analytical means according to claim 2-4, but for performing an analysis is suitable with the goals described.