Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
  • B01L3/502—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
  • G01N31/22—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using chemical indicators
  • G01N31/227—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using chemical indicators for nitrates or nitrites

Definitions

• the present invention relates to a method and a device for the qualitative and quantitative analysis of nitrate ions.
• nitrate ion concentration Semi-quantitative optical analysis methods for determining the nitrate ion concentration are also described. These processes are based on the reduction of the nitrate Nitrite in a pre-reaction and the subsequent detection of the nitrite in a known manner.
• indirect detection has the disadvantages that the nitrate is not completely converted into nitrite and / or that the amount of nitrite originally contained in the test medium, while falsifying the measurement result, is added to the amount of nitrite which is produced in the course of the preliminary reaction Reduction of the nitrate contained in the test medium is obtained.
• the nitrite is detected, for example, with the aid of N- (1-naphthyl) ethylene diammonium dichloride. This substance is carcinogenic.
• the test procedures also use dipsticks which are immersed in the solution to be tested. When handling it, there is a risk that the skin will come into contact with the dangerous detection substance.
• Another object of the present invention is to provide a device which enables this method to be carried out in a qualitative and semi-quantitative manner with particularly simple handling and with the exclusion of any health risk from contact with the reagents contained in the test kit. According to the invention, these objects are achieved by a method for the qualitative and quantitative analysis of nitrate ions according to claim 1 and by a device according to claim 9. Preferred embodiments of the invention are the subject of the dependent claims.
• nitrate ions of a test medium are brought into contact with anesthetic or an anesthetic derivative to form a dye.
• the nitrate ions contained in the sample to be analyzed are brought into contact with anesthetic and / or an anesthetic derivative in the presence of an acid, which leads to a color reaction.
• the methoxy derivative of the extremely toxic strychnine, narcotine is neither carcinogenic nor toxic and is also used as an antitussite with no analgesic effect.
• narcotine derivatives with good solubility, such as acid salts, in particular hydrochlorides, hydrogen sulfates and / or acetates.
• the anesthetic or anesthetic derivative or the d, 1-anesthetic racemate lies in this acidic solution e.g. in a concentration in the range from 0.02 to 0.3 mol / 1 solution, preferably in the range from 0.03 to 0.15 mol / 1 solution, and particularly preferably in the range from 0.03 to 0.06 mol / 1 Solution before.
• Inorganic and / or organic phases are suitable as test medium. According to the invention, however, aqueous phases are preferred, in particular those which are relatively free of organic impurities.
• the method is therefore ideal for the selective, qualitative and quantitative determination of the nitrate content in water with a low organic matrix, e.g. in drinking water, raw water intended for drinking water supply, e.g. Groundwater, surface water, bank filtrate from rivers, cooling water and in mineral water according to the table water regulation.
• waste water may be reduced a very high oxidizable organic fraction, the nitrating acid formed during the course of the reaction and thus lead to poor results.
• the nitrate concentration in the sample which can be analyzed according to the invention is preferably in the range from 0.01 to 100 mg NO3 / l, the measuring range being expandable to higher concentrations if diluted appropriately.
• the mixture is colored with the formation of a carmine-red dye which hitherto unknown structure, which, depending on the nitrate ion concentration in the sample, causes the test kit to turn from slightly pink until deep red.
• the volume ratio of the solution containing the anesthetic or the anesthetic derivative: concentrated acid: sample volume can vary over a wide range.
• the preferred volume ratio according to the invention is in the range of 0.2-0.6 ml: 1-10 ml: 1-3ml.
• the nitrate-containing sample solution is added to the reagent mixture and mixed with it.
• the yellowish orange color of the pre-color reaction disappears and the subsequent color reaction with the formation of a crimson dye is complete after about 3 minutes, ie the color development is then complete. If you let the solution stand for a long time, however, one occurs Color deepening, which can be stopped by dilution with distilled water.
• the color reaction can be stopped up to 20 minutes after the nitrate-containing sample solution has been added. The color of the stopped solution is stable for at least 7 days.
• the method according to the invention is preferably carried out at room temperatures (20 ° C.).
• test medium is free of nitrates (blind reaction)
• the yellowish orange color of the pre-color reaction disappears after the blank sample solution has been added and the solution becomes colorless. After 2 to 10 minutes, the solution then takes on a light pink color.
• the nitrate content of the sample solution is determined by conventional characterization methods coloring of the mixture brought about by the process according to the invention.
• photospectrometrically preferably nitrate contents of the sample solution in the range from 0.01 to 20 mg / 1, in stopped mixtures, ie dilute mixtures, in the range from 0.5 to 100 mg / 1 quantitatively. to be analyzed.
• a semi-quantitative evaluation of the test can be carried out visually. For example, a light comparator, a colorimeter or a color disc comparison is suitable for this.
• a comparison of the color tone of the mixture contained in the device according to the invention with a color scale provided on the device, the color steps of which correspond to different nitrate ion concentrations, is particularly useful for the rapid visual evaluation of the color.
• the device In the transport position, the device is in the rest position, all openings being closed, so that no substances from the device can get into the environment.
• the upper opening and the lower opening are aligned, but the upper outer opening and the upper inner opening are offset from one another so that the sample can be filled into the upper chamber.
• this sample cannot flow out of the upper chamber through the filling tube, since the two openings of the filling tubes are not aligned.
• the reaction position the sample in the upper chamber flows through the upper inner opening aligned with the upper outer opening into the lower chamber, where it is available for the actual reaction step. Finally, in the closed position, all openings are closed again, so that no substance can escape to the outside.
• the sample to be tested is in the upper chamber or is filled into it while it is in the container.
• the container is preferably a fragile glass vessel, which can be destroyed by a simple impact, so that the contents of the glass vessel can pour into the lower chamber.
• the narcotine or anesthetic solution required for the detection reaction is already located there. In this way, the pre-color reaction can be triggered by a simple impact before the device is started up. After development of the primary color, the actual commissioning of the device is then possible.
• the sample is preferably filled into the upper chamber via an upper filler neck.
• the chambers are not arranged centrally in relation to the filling tubes which are inserted one into the other, but are offset to the outside, so that the outer filling tube does not just touch the chamber walls.
• an opening is arranged in a respective upper chamber part, which serves to discharge excess gases.
• the outlet opening can be provided as an elongated hole in order to enable better emptying of each chamber.
• the inner filler pipe or outer filler pipe is preferably expanded in the shape of a trumpet. This creates a suction effect when emptying. It is preferred to attach a pointer to the lower disk, which is guided upwards via an angle piece to a scale which is attached around the hand disk. This enables the individual positions to be set and read precisely.
• the openings provided in the outer filling tube viewed from the outer filling tube, face the largest possible radial cross section to the chamber wall. This ensures that the respective chamber can be completely emptied.
• Fig. 1 shows a cross section of the invention
• Fig. 2 shows a hand disk of the device
• a rotatable hand disk 1 and a lower disk 7 inserted therein are shown.
• the hand disk has a circumferential run 2, by means of which it can be rotated with respect to the lower disk by hand.
• the hand disk has a nozzle 16 for filling the sample or the test material.
• the connector 16 can be closed with the aid of a plug 17.
• the nozzle 16 opens into an upper opening 3 of the hand pane.
• the structure of the hand pane is explained in more detail in FIG. 2.
• the hand pane is connected in its central region to a cylindrical inner filler tube 4 which is sealed upwards by a closure plate 18.
• the lower disc 7 is provided as a counterpart to the hand disc and adapted to this.
• the lower disk engages in a corresponding recess or groove of the hand disk by means of a projection formed on its circumference.
• the lower disk has a lower opening 8, which is aligned with the upper opening 3 at a certain rotational position.
• a connected outer fill pipe 9 is provided in the middle part of the disc corresponding to the inner fill pipe, which has a slightly larger diameter than the inner fill pipe.
• a receiving surface 20 is provided on the lower disk for an upper chamber 12, which is attached to it in a sealing manner.
• the upper chamber receives the sample.
• An intermediate chamber 13 adjoins the upper chamber 12 at the bottom and is sealingly attached to the upper chamber.
• the intermediate chamber serves as a sealing chamber or stabilization chamber.
• a lower chamber 19 is provided at the bottom of the intermediate chamber, the walls of which extend upwards simultaneously serve as holding elements for the two upper chambers and fasten them.
• the lower chamber holds the test substance, e.g. Narcotin.
• Openings for the passage of the outer filling tube 9 are provided in the same place. Contact areas are sealed.
• two upper inner openings 6 are provided in the inner filler tube 4, which are aligned with two upper outer openings 11 of the outer filler tube 9 at a certain rotational position of the hand disk.
• two lower outer openings 10 are provided in the outer filling tube 9, which can be aligned with two corresponding lower inner openings 5 of the inner filling tube 4. These four openings are shown in their aligned position in FIG. 1. Two aligned openings form a passage.
• the lower chamber 19 is connected to the lower plate on the receiving surface 20 and closely fits the upper chamber and the intermediate chamber.
• a container 14 for receiving the strong acid is formed, which is preferably made of glass.
• the glass bulb has the same diameter as the lower chamber and is inserted into it after filling. This gives the possibility of destroying the glass vessel from the outside by impact, and of emptying the contents of the glass vessel into the lower chamber 19.
• the volumes of the individual chambers or the container are so . designed that the amounts of reagent specified in the chemical process steps from the chambers or the container be included.
• a ventilation opening 22 is provided opposite the lower inner opening 5 in the inner filling tube 4, which serves to vent the intermediate chamber.
• the upper inner opening 6 is designed as an elongated hole in order to enlarge the discharge cross section.
• the upper chamber has webs (not shown) which limit the volume of the chamber to, for example, 2 ml. This ensures that only a corresponding quantity of the sample or the test material reaches the lower chamber for reaction in accordance with the corresponding chemical process step.
• the intermediate chamber could also be used to hold reagents, e.g. instead of the glass container. However, this is preferred because it can also absorb reagents that must not come into contact with the plastic walls of the chambers.
• the photometrically determined nitrate content is 55 mg NO / l; the actual nitrate content of the sample solution used was 75.1 mg NO / l.
• the method according to the invention is carried out with the device according to the invention as follows. First, the glass bulb is destroyed by impact on a hard edge, so that the strong acid escapes into the lower chamber 19. Then the rotatable Handwheel 1 of the device rotated from its transport position into the sample inlet position. The plug 17 of the device is then removed at room temperature and the sample to be analyzed for its nitrate content is filled into the upper chamber 12 of the device via the connector 16. Then the water inlet is closed again by the plug 17, so that the upper opening 3 is also closed. The rotating hand disk is rotated further from the sample inlet position into the reaction position, so that the sample located in the upper chamber passes down into the lower chamber or reaction chamber 19.

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• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• Physics & Mathematics (AREA)
• Molecular Biology (AREA)
• Biochemistry (AREA)
• Biophysics (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Hematology (AREA)
• Clinical Laboratory Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)

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Citations (4)

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• 1988
  • 1988-04-27 DE DE19883814230 patent/DE3814230A1/de active Granted
• 1989
  • 1989-04-27 AU AU35794/89A patent/AU3579489A/en not_active Abandoned
  • 1989-04-27 WO PCT/EP1989/000468 patent/WO1989010561A1/de unknown

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