DE102009017932A1 - Continuous quantitative determination of oxidizable chemical compound, preferably hydrocarbons and other chemical ingredients in various areas of industry and research, involves taking sample from experimental media - Google Patents

Abstract

Continuous quantitative determination involves taking sample from experimental media, where the sample is divided into two equal parts. The former portion is fed in a measurement side (1) of a measuring device (2), while the latter portion is supplied in a comparison kit (3) of the measuring device. The measurement side and comparison side have same volume and same geometric structure. The former portion is oxidized in a reactor (4) at elevated temperature to form gaseous reaction products, where the latter portion is heated in a furnace (5). Continuous quantitative determination involves taking sample from experimental media, where the sample is divided into two equal parts. The former portion is fed in a measurement side of a measuring device, while the latter portion is supplied in a comparison side of the measuring device. The measurement side and comparison side have same volume and same geometric structure. The former portion is oxidized in a reactor at elevated temperature to form gaseous reaction products, where the latter portion is heated in a furnace. An equal and parallel mass flow is set for the both portions. The mass flow is fed to a measuring vessel (6) and reference cell (7), where concentration of oxidizable chemical components is calculated in the experimental media.

Description

The The present invention relates to a continuous process quantitative determination of at least one oxidizable chemical Compound in samples from a gaseous, liquid or solid examination medium according to claim 1 and a method for continuous measurement of carbon content an aqueous investigation medium, which hydrocarbons contains, according to claim 20.

The This application relates to quantitative analysis and especially the online measurement for quantitative analysis Hydrocarbons (HC) in all types of media, for example Gases, in particular gases under overpressure, such as z. B. compressed air.

In many technical areas, in which compressed gases are used, it is important to know the content of undesirable impurities such as HC but also NO _x and / or the sulfur content in order to make a statement about the quality or usability of the compressed gas. For example, different requirements apply to the maximum content of HC for respiratory gases and those in the industrial sector, eg. B. in the field of pneumatics used. While in respiratory gases only traces of HC without risk of damage to the lungs, z. B. by a toxic pulmonary edema, may be present in the breathing gas, higher limits apply to industrial applications. However, for example, an excessively high HC, NO _x and / or sulfur content is critical, for example, for seals made of polymer material, so that premature wear and / or safety risks can occur during the operation of pneumatic systems.

such KW loads, however, also result - depending on the investigation medium - from a variety of substances, in particular organic solvents, Pesticides, pharmaceuticals, oil and other lubricants, Petrol, antifreeze and de-icing agents. Thus, the areas of application lie for the measurement of HC - in addition to the above-mentioned pressure gas range - in Power plants, oil refineries, the chemical industry, Food industry, textile and paper industry, sewage treatment as well as airports.

by virtue of The tremendous importance shown here are reliable procedures for the determination of HC in examination media - in the example of Compressed gases already in the production of compressed gases and in the final product - as well as for process and quality control desirable in the above-mentioned areas.

For this purpose, a number of methods and measuring devices are known from the prior art, with which in principle the HC content, NO _x - and sulfur content can be measured in a medium, but their detectability limits are essentially in the ppm (part per million) range and thus allow concentration measurements, based on the "normal cubic meter" of about> 1 mg / Nm ^{3 of} assay medium. A standard cubic meter [Nm ³ ] in the compressed air industry and for the purposes of the present invention is the "standard volume" of a gas, expressed as a pressure of 1.013 bar and a temperature of 20 ° C at 0% humidity.

In the prior art, HC are usually oxidized in samples from a study medium by complete combustion to CO ₂ and the resulting CO ₂ by means of photospectroscopic methods, for example by IR absorption quantitatively, calibrated with predetermined standards, measured and then the KW content typically determined by total organic carbon (TOC). Analogously, NO _x (as NO ₂ ) and sulfur SO _x (as SO ₂ ) can be determined based on their oxidation products after appropriate calibration.

For this purpose, a number of devices are available from the prior art. To highlight, for example, in the company prospectus "Water, TOC-TO-TNb, Equipment for Analysis and Sample Preparation, Technical Information", March 2007 described online TOC analyzers "GO-TOC 100, GO-TOC 1000 and GO-TOC P" by Gröger & Fruit Sales and Service GmbH, Hans-Urmiller-Ring 24, 82515 Wolfratshausen, the assignee of the present patent application.

Furthermore, from the EP 199 365 A2 an infrared two-jet gas analyzer, known in which the infrared radiation emanating from a radiation source is divided into a pulsating measuring beam and a pulsating comparison beam by means of a beam splitter with a downstream light chopper. The measuring beam passes through a cuvette filled with measuring gas, with a measuring gas-specific intensity attenuation taking place, while the reference beam passes through a comparison cuvette filled with a reference gas, preferably a nonabsorbing inert gas. Each cuvette is in each case arranged downstream of a gas-filled receiver chamber, in which the radiation emerging from the respective cuvette generates pressure fluctuations due to absorption. Due to the pre-absorption by the sample gas in the measuring cell, the pressure fluctuations caused in the receiver chambers are different. The resulting pressure difference is determined by means of a lying in a connection between the two receiver chambers pressure and Strö detected by weighting the Differnezsignals thereby obtained, a measured value is generated. The weighting factor for generating the measured value can be determined by filling the measuring cuvette with a calibration or calibration gas having a known absorption behavior, wherein the weighting factor is set such that a measured value corresponding to the calibration value of the calibration or calibration gas results.

A However, such measuring device has the disadvantage that dirt entry into the cuvette for permanent recalibrations leads and thus such a device only conditionally suitable for online measurement in continuous operation.

An improved dual-jet gas analyzer as well as improved calibration of such dual-jet gas analyzers are known in US Pat DE 195 47 787 C1 and EP 780 681 B1 described. Specific applications are not mentioned in the cited patents.

The methods described in the prior art have in common that they can not or only to a very limited extent be used for online trace analysis in the field of HC analysis:
For example, this requires the ISO 8573-1, -2 and -5 to determine the permissible residual HC content in compressed air with regard to quality class 1, that the condition ≤ 0.01 mg KW / Nm ³ must be fulfilled. For this a quantitative detectability limit (LQD) of 0.001-0.002 mg KW / Nm ³ gas is absolutely necessary.

There are currently no real online measurements on the market to determine the hydrocarbon (HC) content in air or other gases that have such an LQD of ≤ 0.001 mg HC / Nm ^{3 of} gas and all hydrocarbons of up to 40 C atoms and prove their derivates valid as summation parameters.

The available analysis systems for the determination of HC in air or compressed air are either from the resolution (= detection limit) not accurate enough (resolution up to about 0.1 mg KW / Nm ³ ) or too expensive for use in the compressed air technology, too Material- and maintenance-intensive laboratory systems: FID-based TOC systems with enrichment or GC-MS systems with enrichment. The analysis systems with accumulation tube accumulation systems (trapp systems) generally have the disadvantage that they are not suitable for the broad range of compounds - HCs having 1 to 40 carbon atoms, since these systems accumulate in a trapping phase in a trap and a subsequent desorption (usually thermally assisted) based in the measurement phase. In this process, there is an incomplete desorption for larger molecules. Measuring errors (too low measured values) and carry-over in later measuring cycles (excessive measured values) are the result.

Similar Effects also occur in GC measurements. In addition comes when using Trapp systems and GC systems for dead times in online surveillance up to 30 min and more (at GC systems).

One Another problem with these measuring methods is the high demand for expensive pure gases and calibration gases. Is, as with FID systems, hydrogen as fuel gas required so comes an increased risk of explosion aggravating added.

It is therefore an object of the present invention to provide a reliable method for the continuous quantitative determination of HC in a concentration range of ≦ 0.001 mg HC / Nm ³ gas, wherein an online measurement in continuous operation without complex recalibrations and measurement interruptions are reliably possible.

These Task is achieved by a method according to claim 1 and by a method according to claim 20 solved.

The Subclaims represent preferred embodiments of the invention.

The basis of the invention described here is the sum parameter TOC (Total Organic Carbon) known from the exhaust gas and wastewater technology. In the TOC method, all organic compounds in the compressed air or compressed gas are measured in a purely quantitative manner, in which they undergo total oxidation and the CO _{2 produced is} measured directly or indirectly. The advantage of this method is that the cumulative total amount of hydrocarbons in the gas stream as a whole is detected, and not split into individual compounds. Thus, the LQD is further lowered. The measured variable of the process is the CO ₂ increase converted by total oxidation into mg C / Nm ³ .

For the measurement method described according to the invention is a combustion of hydrocarbons at about 600 ° C-1500 ° C (if necessary on a suitable catalyst) and subsequent determination of the CO ₂ concentration by NDIR, in particular FT-IR measurement used.

• a) Nehmen einer Probe aus dem Untersuchungsmedium;
• b) Aufteilen der Probe in zwei gleiche Teile;
• c) Zuführen des ersten Teils der Probe [P_ox] zu einer Messseite einer Messvorrichtung und Zuführen des zweiten Teils der Probe [P_Vgl] zu einer Vergleichsseite der Messvorrichtung, wobei die Messseite und die Vergleichsseite das gleiche Volumen und den gleichen geometrischen Aufbau aufweisen;
• d) Oxidieren von P_ox in einem Reaktor bei erhöhter Temperatur zu gasförmigen Reaktionsprodukten der Oxidation [R_ox] und Erwärmen von P_Vgl auf eine solche Temperatur in einem Ofen, dass die zu erfassenden chemischen Verbindungen gasförmig vorliegen;
• e) Auskondensieren von Wasser aus R_ox und P_Vgl;
• f) Einstellen eines gleichen Massenstroms für R_ox und P_Vgl;
• g) Zuführen des R_ox-Massenstroms zu einer Messküvette und Zuführen des P_Vgl-Massenstroms zu einer Vergleichsküvette, wobei die Messküvette und die Vergleichsküvette von Licht, welches für die Detektion von R_ox geeignet ist, durchstrahlt werden;
• h) gleichzeitiges Erfassen einer Veränderung der Lichtintensität des eingestrahlten Lichtes nach Durchlauf durch Messküvette und Vergleichsküvette in einer den beiden Küvetten nachgeschalteten für R_ox spezifischen Messzelle, um einen Differenzwert der Menge an Rox zwischen Messküvette und Vergleichsküvette zu bilden; und
• i) Berechnen der Konzentration der oxidierbaren chemischen Verbindung im Untersuchungsmedium.

In its broadest embodiment, the present invention relates to a method for the continuous quantitative determination of at least one oxidizable chemical compound in samples from a gaseous, liquid or solid assay medium, wherein the reaction products of the oxidation are spectrophotometrically detectable, and wherein the process comprises the following steps:

• a) taking a sample from the examination medium;
• b) dividing the sample into two equal parts;
• c) feeding the first part of the sample [P _ox ] to a measuring side of a measuring device and feeding the second part of the sample [P _Vgl ] to a comparison side of the measuring device, wherein the measuring side and the comparison side have the same volume and the same geometric structure;
• d) oxidizing P _ox in a reactor at elevated temperature to gaseous reaction products of the oxidation [R _ox ] and heating P _Vgl to such a temperature in an oven that the chemical compounds to be detected are gaseous;
• e) Condensation of water from R _ox and P _Vgl ;
• f) setting an equal mass flow for R _ox and P _Vgl ;
• g) supplying the R _ox mass flow to a measuring cuvette and feeding the P _Vgl mass flow to a reference cuvette, the cuvette and the reference cuvette being irradiated by light suitable for the detection of R _ox ;
• h) simultaneously detecting a change in the light intensity of the irradiated light after passing through the cuvette and reference cuvette in a downstream of the two cuvettes for R _ox specific measuring cell to form a difference value of the amount of Rox between cuvette and reference cuvette; and
• i) calculating the concentration of the oxidizable chemical compound in the assay medium.

The invention further relates to a method for continuously measuring the carbon content of an aqueous sample medium containing hydrocarbons, comprising the following steps:
Taking a water sample from the study medium; Separating inorganic carbon from the water sample by acidification and repellency as CO ₂ ;
Feeding the inorganic carbon-free water containing only organic carbon into a vaporization and combustion chamber of a reactor to a TOC measuring side of a measuring device and feeding a pure hydrocarbon-free reference gas (zero gas) to a reactor of a comparison side of the measuring device and the reactor, wherein the measurement side and the comparison side have the same gas flows, the same volume and the same geometric structure;
Oxidizing the hydrocarbons in the reactor at elevated temperature to CO ₂ and heating the zero gas in the reactor to the same temperature;
Condensation of water vapor from the gas streams leaving the two reactors;
Supplying the measuring side CO ₂ mass flow to a measuring cuvette and feeding the zero gas mass flow to a reference cuvette, the cuvette and the reference cuvette being irradiated by light suitable for detecting CO ₂ ;
simultaneous detection of a change in the light intensity of the incident light after passing through the measuring cuvette and comparison cuvette in a CO ₂ -specific measuring cell downstream of the two cuvettes, in order to form a difference value of the amount of CO ₂ between measuring cuvette and reference cuvette; and calculating the carbon content as the TOC of the water sample in the assay medium.

With the method according to the invention, it is possible for the first time to provide a TOC system for the measurement of HC with an LQD of 0.001 mg KW / Nm ³ , with which one can continuously reliably measure such small amounts of HC over a long time online.

Further Advantages and features arise from the description of Embodiments and with reference to the drawing.

It shows:

1 a schematic representation of the method according to the invention using the example of online TOC measurement in compressed air;

1A a schematic representation of the inventive method using the example of TOC measurement in a gas with oxygen deficiency;

2 a schematic representation of the method according to the invention using the example of the TOC measurement in water; and

3 a schematic representation of the method according to the invention using the example of TC and TIC measurement in water.

In the first step of the invention, a TOC system was developed for the measurement of HC with an LQD of 0.001 mg KW / Nm ³ under ambient pressure ("room air measurement"), hereinafter referred to as "air TOC".

Operating principle Online Air TOC: ( 1 : "Online Air TOC")

Unlike a conventional TOC If the absolute value of the organically bound carbon in the gas stream is not determined, the delta is formed from the concentrations of 2 gas streams. The TOC value is determined by measuring and converting the CO ₂ concentration in the gas streams.

For this purpose, gas is taken from a compressed air line (about 120 l / h). The withdrawn gas stream is now through a heated to 150-170 ° C sampling line in the meter 2 directed. In the meter 2 Now the gas flow is divided into two equal parts and parallel through the measuring side 1 and the comparison page 3 directed. For this it is necessary that both sides have an exactly identical volume and an identical gas flow. The control of the gas flow is provided by two pumps E-1 and E-6 and two mass flow controllers 15 and 16 ensured.

measuring side 1 :

The gas flow on the measuring side 1 is now through an oven as a reactor 4 with, if necessary, catalytically coated filling passed. The temperature in the reactor 4 is in the example case 1250 ° C and the residence time is z. B. at up to 1 min.

In the reactor 4 all of the HC in the gas stream is oxidized to CO ₂ and water.

From this point, no falsification of the measurement results by deposition of HCs in the lines can be done because the medium to be determined, CO ₂ , is gaseous.

So now the CO ₂ detector (in the example, a Siemens Ultramat 6 Special version with comparative physics) and the mass flow control does not damage with moisture or dust, the gas flow through a cyclone-cooling dryer 11 and through a particle filter 13 directed. Subsequently, the mass flow control takes place.

Now the gas is in the cuvette 6 passed the detector and the CO ₂ concentration of the gas with the comparative cuvette 7 physically compared. The formed difference value is the measure for the KW load of the gas.

comparison 3 :

The comparison page 3 is identical to the measurement page 1 built up. The only difference is that the oven 5 in the example case, only to 110 ° C is heated to avoid deposition of water or HC. An oxidation of the HC in the gas stream of the comparison side 3 does not take place.

Thus, the difference in the CO ₂ concentrations of the measuring and comparison side 1 respectively. 3 exclusively on the oxidation of HC on the measuring side 1 due.

The advantage of this type of measurement is that the measured value relates to the concentration difference of the two detector sides and is thus largely independent of fluctuations in the input concentration of CO ₂ .

Measuring principle of the measuring device used, for. Ultramat 6 SIEMENS company:

The high resolution, with small size of the detector, is achieved by the special measurement method of the company Siemens.

Unlike other FT-IR CO ₂ detectors, IR absorption is not measured by opto-electronic photo-multipliers, which would require a much larger, more sensitive, and more expensive design. Rather, in the measuring device used to carry out the method according to the invention 2 the cuvettes 6 the measuring side 1 and the cuvettes 7 the comparison page 3 alternately illuminated in quick alternation by means of an IR source.

Following the measuring cuvette 6 The IR beam is in each case through a small measuring cell 8th passed, which is filled with CO ₂ . The measuring cells 8th the measurement and the comparison page 1 respectively. 3 are connected by flow channels. Due to the different concentrations of CO ₂ in the cuvette 6 and the comparison cuvette 7 the absorption rates on the two sides are different, ie in the measuring cells 8th arrive at different amounts of IR radiation. This causes it by excitation of the CO ₂ molecules in the measuring cells 8th to a gas flow from one to the other measuring cell 8th comes. This flow is measured thermally via tungsten wires in the flow channels.

The measured flow data are converted by the device into concentration values. The result is the CO ₂ concentration difference value (crude dTOC).

Of the Methane content of ambient air (0.97 ppmg German average) is always present as a basic load. For many applications however, it is necessary to have a dTOC value corrected for the methane content and to record the methane content separately.

This is possible without problems with the method according to the invention and can be realized by means of a selective IR measurement in parallel with the raw dTOC measurement. Here, the circumstance is ge that uses the methane on the non-burned comparison side 3 contained in its original concentration, but on the measurement side 1 by the total oxidation in the reactor 4 was completely converted into CO ₂ . In this way, the CO ₂ concentration and the CH ₄ concentration can be elegantly adjusted by means of a downstream methane measuring cell 9 realize at the same time. The special construction and measuring method of the exemplified device makes it possible that these two measurements can be done in a measuring unit, and thus are absolutely parallel. This significantly reduces the measurement error.

The CO ₂ measured value can then be normalized to any KW standard (eg toluene).

Especially Advantageously, an auto-calibration can be realized as an additional function be, d. H. the measuring device can be at predetermined intervals calibrate yourself to zero:

Principle of the AUTOCAL function:

The AUTOCAL function is based on an electronic and a mechanical Component.

The electronic component controls the control outputs of the measuring device used at freely selectable intervals 2 , z. Ultramat 6 , at. With these control outputs solenoid valves are controlled, which redirect the gas flows in the TOC, so that a self-calibrating gas loop 20 arises for the zero point adjustment.

The mechanical component of the AUTOCAL function comprises those in the process flow diagram "Online Air TOC" in accordance with 1 at reference numerals 20 drawn gas paths and valves.

In order to carry out a calibration, the gas flows from the measuring side are now 1 and from the comparison page 3 , not discharged into the room via the 2/3-way valve V-7, as in measuring mode, but directed into the mixing tank E-9. In mixing tank E-9, the two gas streams now mix and are then returned to the measuring side via the 2/3-way valves V-5 and V-6 1 or comparison page 3 returned. It is formed as a gas cycle. After about 10-15 minutes, the same CO ₂ concentration sets in on both sides. This can be clearly seen in the measured values of the dTOC. This condition corresponds to a CO ₂ concentration difference of zero. The AUTOCAL function now sets the measured value to zero. Now it is switched back to normal measuring mode.

How experimental series showed the internal structure of the reactor 4 and the reactor temperature, if appropriate, be adapted to the gas composition to be analyzed:
Contains the gas to be tested KW in the form of aerosols so must in the reactor 4 both an aerosol separation and the combustion can be ensured. This is best done with knitted fabrics and fine filters made of glass fiber, ceramics, metal wire (mainly steel, titanium or tantalum) or ceramic sintered filters. At low furnace temperatures, these separators are to be coated catalytically to prevent coking of the KW. The catalysts are platinum / paladium, and mixtures of CuO (about 40% by mass) and MnO ₂ (about 50% by mass) (cocatalysts titanium oxide, vanadium pentoxide and iron oxide (addition to 100% by mass) or mixtures of these compounds used) proven.

According to 1A For example, it is also possible to realize a TOC measurement by means of the method according to the invention in gases with an oxygen deficiency. This is done via a metering pump 17 H ₂ O ₂ on the measuring side 1 added. By adding the H ₂ O ₂ , the volume is not changed, since the water content is then condensed out.

With the method according to the invention, the measurement of gases under pressure can also be realized:
To according to the ISO 8573 To be able to carry out an isokinetic partial flow measurement, it must be ensured that the gas extracted in isokinetically (compare ISO8573-2 and -5 ) do not condense prior to the measurement and this leads to a falsification of the measured values.

Around To ensure this will be the two stoves each installed in a pressure vessel, or the ovens be made pressure resistant. In addition, the stoves attached directly to the isokinetic sampling point so that the gas flow without deflection, under system pressure in the furnaces can. Here, the combustion of the gas takes place under system pressure. This has the added benefit of being due to compression of the gas the oven size, while remaining constant Residence time, can be significantly reduced. For example, at a system pressure of at least 10 bar (absolute) can the oven size reduced to 1/10.

Since all substances relevant for the measurement (in this case CO ₂ and CH ₄ ) are present in gaseous form after combustion, the gas can now be relieved to ambient pressure and the TOC measurement can take place as before at ambient pressure. Due to the existing system pressure, the pumps can be saved in this design compared to the system from the first step. This leads to a reduction in size and simplification of the construction.

As shown in the course of development, the inventive method can also be used to determine other gas components than KW. All substances whose oxidation products are IR-active can be detected by the method according to the invention. For this purpose, only the CO ₂ measuring cell has to be replaced by a corresponding measuring cell for the oxidation product of the respective component.

As shown by the case of CO ₂ and CH ₄ , parallel measurement in an IR system is possible for certain substance pairs. otherwise theoretically any number of IR systems can be connected in series since the physical measurement does not have a destructive effect on the oxidation products to be measured. It comes only to a temporal offset of the respective associated measured values of the individual gas components.

The following substance groups could be successfully tested with appropriate measuring cells:
Sulfur compounds -> proof as SO ₂
Nitrogen compounds -> detection as NO

Application in water analysis ( 2 and 3 )

It has also shown that the comparative measurement method The Air TOC also makes use of the measuring method for To fundamentally improve the TOC of water:

Working principle of a conventional Online TOCs:

The raw water sample is acidified to about <pH 2 prior to analysis and outgassed to rid it of inorganic carbon (by expelling CO ₂ from carbonates and bicarbonates).

From a metering pump, the measuring water in a defined amount conveyed into the evaporation and combustion chamber of the oxidation furnace.

in the Oxidation furnace burns the carbon contained in the water Carbon dioxide. For this purpose, HC-free zero gas in a defined amount added.

In an afterburner space makes a catalyst the perfect one Burning the carbon to carbon dioxide safely. in a gas cooler the gas stream freed from water vapor and into an acid filter guided.

There any acid residues are removed. Thereafter, the sample gas stream enters the gas analyzer, where the amount of CO _{2 is} determined by means of an NDIR gas analyzer. The display is in mg C / l.

The conventional methods thus have the problem that they rely on CO ₂ and zero gas. This can be provided in various ways: on the one hand from compressed gas cylinders or from zero air generators. Both possibilities have considerable difficulties in continuous operation. In the case of gas cylinders, the bottle must be replaced in good time. For zero-air generators, the CO ₂ adsorber (usually called soda lime) must be replaced regularly. Especially with soda lime accurate life determination is not possible. Thus, always precaution must be exchanged. At least every gas or soda lime replacement requires a recalibration of the zero point of the system. Not to mention the considerable financial effort for the exchange.

If one now uses a TOC system structure according to the invention as in process flow diagram online H ₂ O-TOC ( 2 ), in which also a comparative IR measurement is used as for air-TOC for CO ₂ determination, so can be dispensed with the CO ₂ -free of the zero gas.

The fundamental difference to the conventional method is that the HC-free zero gas by thermal oxidation can be used on the one hand in the conventional sense as a carrier gas for water oxidation, but is used in addition to the gassing of the reference cuvette. In the CO ₂ measurement, the CO ₂ content of the zero gas is thus eliminated by the comparative measurement. Now that the lime can be dispensed with, only the hydrochloric acid remains, which is used for outgassing the TIC (Total Inorganic Carbon), which can lead to measured value distortions as a result of impurities with HC (eg from ion exchange resins).

As shown by the TOC structure according to the process flow diagram "Online H ₂ O-TC / TIC-TOC" ( 3 ), can be hidden by the inventive method now also this error. In addition, the measured quantities TC (Total Carbon) and TIC can be determined simultaneously and via the equation: TOC = TC - TIC the TOC value can be determined by calculation.

in principle This setup is based on the online TOC setup, however the TC side burned the raw water without acidification and thus the TC (TC = TIC + TOC) is subsequently measured.

On The TIC side acidifies the raw water just like the online TOC, however, we subsequently just piped the strip gas into the oven and discarded the degassed water. The stripping gas only contains the TIC component of the raw water. Possible KW impurities HCl acid was discarded with the degassed water.

The CO ₂ measurement of the TIC side is analogous to the CO ₂ measurement of the TC side.

As Test runs with ultrapure water systems showed that they are suitable the inventive method for continuous Online TOC or online TC / TIC measurement optimal for monitoring of KW concentrations in the so-called part-per-billion range (ppb range).

Of course own the method according to the invention also for non-continuous operation with individual samples, because here by a longer measurement and consideration of the course of analysis a more accurate and clearer determination of the sample possible is than was possible in the prior art so far.

E

Beheizte Probennahmeleitung 170°C/Umgebungsdruck

A

Gasausgang

KA

Kondensat-Ausgang

1

Messseite

2

IR-Spektrometer

3

Vergleichseite

4

Reaktor der Messseite (Standardeinstellungen: +1000°C/T(Raum) = 1 min)

5

Reaktor der Vergleichsseite (Standardeinstellungen: +120°C/T(Raum) = 1 min)

6

Mess-Küvette der IR-Messeinheit 1

7

Vergleichs-Küvette der IR-Messeinheit 1

8

Messzellen CH4 der IR-Messeinheit 1

9

Messzellen CO2 der IR-Messeinheit 1

10

IR-Messeinheit zur Messung der CO2-Absolut-Konzentration

11

Peltier-Kühler Messseite (Standardeinstellung: +0,5°C)

12

Peltier-Kühler Vergleichseite (Standardeinstellung: +0,5°C)

13

Partikel-/Säure-Filter der Messseite

14

Partikel-/Säure-Filter der Vergleichseite

15

Massflowcontroller Messseite (Standard wert: 1 Nl/min)

16

Massflowcontroller Vergleichseite (Standard wert: 1 Nl/min)

17

Membranpumpe Messseite

18

Membranpumpe Vergleichseite

19

Mischbehälter mit Rasching-Ring-Füllung

20

Selbst-Kalibrier-Gas-Schleife

21

2/3-Wege-Hahn: Umschaltung Gasausgang/Kalibrierschleife

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2/3-Wege-Hahn: Umschaltung Messen Vergleichsseite/Kalibrierschleife

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2/3-Wege-Hahn: Umschaltung Messen Messseite/Kalibrierschleife

24

Mehrkanal-Schlauchpumpe zur Kondensatableitung (Die Kondensatschlauchpumpe muss bei der Kalibrierung gestoppt werden!)

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IR-Messeinheit 1 zur Vergleichsmessung (ΔTOC-CO2-Messung)

26

Chopperkammer der IR-Messeinheit 1

27

IR-Quelle der IR-Messeinheit 1

28

Messzellen CO2 der IR-Messeinheit 2

29

Mess-Küvette der IR-Messeinheit 2

30

Vergleichs-Küvette der IR-Messeinheit 2

31

Chopperkammer der IR-Messeinheit 2

32

IR-Quelle der IR-Messeinheit 2

33

Auswerteelektronik/Steuerung IR-Spektrometer

Legend too 1 "Online Air TOC" With methane compensation and self-calibration system using solenoid-operated gas loop

e

Heated sampling line 170 ° C / ambient pressure

A

gas output

KA

Condensate output

1

measuring side

2

IR spectrometer

3

comparison

4

Measuring side reactor (default settings: + 1000 ° C / T (room) = 1 min)

5

Reference side reactor (default settings: + 120 ° C / T (space) = 1 min)

6

Measuring cuvette of the IR measuring unit 1

7

Comparison cuvette of the IR measuring unit 1

8th

Measuring cells CH4 of the IR measuring unit 1

9

Measuring cells CO2 of the IR measuring unit 1

10

IR measuring unit for measuring the CO2 absolute concentration

11

Peltier cooler measuring side (default: + 0.5 ° C)

12

Peltier cooler comparison page (default: + 0.5 ° C)

13

Particle / acid filter on the measuring side

14

Particle / acid filter of the comparison page

15

Mass flow controller measuring side (standard value: 1 Nl / min)

16

Mass flow controller comparison page (default value: 1 Nl / min)

17

Diaphragm pump measuring side

18

Diaphragm pump comparison page

19

Mixing container with Rasching ring filling

20

Self-calibration gas loop

21

2/3-way stopcock: changeover gas outlet / calibration loop

22

2/3-way stopcock: Switchover Measure comparison side / calibration loop

23

2/3-way stopcock: changeover measuring measuring side / calibration loop

24

Multi-channel peristaltic pump for condensate drainage (The condensate hose pump must be stopped during calibration!)

25

IR measurement unit 1 for comparison measurement (ΔTOC-CO2 measurement)

26

Chopper chamber of the IR measuring unit 1

27

IR source of the IR measuring unit 1

28

Measuring cells CO2 of the IR measuring unit 2

29

Measuring cuvette of the IR measuring unit 2

30

Comparison cuvette of the IR measuring unit 2

31

Chopper chamber of the IR measuring unit 2

32

IR source of the IR measuring unit 2

33

Evaluation electronics / control IR spectrometer

E

Beheizte Probennahmeleitung 170°C/Umgebungsdruck

EO

Zuleitung H2O2 (Oxidationsmittel)

A

Gasausgang

KA

Kondensat-Ausgang

1

Messseite

2

IR-Spektrometer

3

Vergleichseite

4

Reaktor der Messseite (Standardeinstellungen: +1000°C/T (Raum) = 1 min)

5

Reaktor der Vergleichsseite (Standardeinstellungen: +120°C/T (Raum) = 1 min)

6

Mess-Küvette der IR-Messeinheit 1

7

Vergleichs-Küvette der IR-Messeinheit 1

8

Messzellen CH4 der IR-Messeinheit 1

9

Messzellen CO2 der IR-Messeinheit 1

10

IR-Messeinheit zur Messung der CO2-Absolut-Konzentration

11

Peltier-Kühler Messseite (Standardeinstellung: +0,5°C)

12

Peltier-Kühler Vergleichseite (Standardeinstellung: +0,5°C)

13

Partikel-/Säure-Filter der Messseite

14

Partikel-/Säure-Filter der Vergleichseite

15

Massflowcontroller Messseite (Standard wert: 1 Nl/min)

16

Massflowcontroller Vergleichseite (Standard wert: 1 Nl/min)

17

Membranpumpe Messseite

18

Membranpumpe Vergleichseite

19

Mischbehälter mit Rasching-Ring-Füllung

20

Selbst-Kalibrier-Gas-Schleife

21

2/3-Wege-Hahn: Umschaltung Gasausgang/Kalibrierschleife

22

2/3-Wege-Hahn: Umschaltung Messen Vergleichsseite/Kalibrierschleife

23

2/3-Wege-Hahn: Umschaltung Messen Messeite/Kalibrierschleife

24

Mehrkanal-Schlauchpumpe zur Kondensatableitung (Die Kondensatschlauchpumpe muss bei der Kalibrierung gestoppt werden!)

25

IR-Messeinheit 1 zur Vergleichsmessung (ΔTOC-CO2-Messung)

26

Chopperkammer der IR-Messeinheit 1

27

IR-Quelle der IR-Messeinheit 1

28

Messzellen CO2 der IR-Messeinheit 2

29

Mess-Küvette der IR-Messeinheit 2

30

Vergleichs-Küvette der IR-Messeinheit 2

31

Chopperkammer der IR-Messeinheit 2

32

IR-Quelle der IR-Messeinheit 2

33

Auswerteelektronik/Steuerung IR-Spektrometer

34

Dosierpumpe für die Zudosierung des Oxidationsmittels (z. B. H2O2)

Legend too 1A "Online air TOC for oxygen-deficient gas without oxygen content" With methane compensation and self-calibration system via solenoid-operated gas loop

e

Heated sampling line 170 ° C / ambient pressure

EO

Supply line H2O2 (oxidizing agent)

A

gas output

KA

Condensate output

1

measuring side

2

IR spectrometer

3

comparison

4

Measuring side reactor (default settings: + 1000 ° C / T (room) = 1 min)

5

Reference side reactor (default settings: + 120 ° C / T (space) = 1 min)

6

Measuring cuvette of the IR measuring unit 1

7

Comparison cuvette of the IR measuring unit 1

8th

Measuring cells CH4 of the IR measuring unit 1

9

Measuring cells CO2 of the IR measuring unit 1

10

IR measuring unit for measuring the CO2 absolute concentration

11

Peltier cooler measuring side (default: + 0.5 ° C)

12

Peltier cooler comparison page (default: + 0.5 ° C)

13

Particle / acid filter on the measuring side

14

Particle / acid filter of the comparison page

15

Mass flow controller measuring side (standard value: 1 Nl / min)

16

Mass flow controller comparison page (default value: 1 Nl / min)

17

Diaphragm pump measuring side

18

Diaphragm pump comparison page

19

Mixing container with Rasching ring filling

20

Self-calibration gas loop

21

2/3-way stopcock: changeover gas outlet / calibration loop

22

2/3-way stopcock: Switchover Measure comparison side / calibration loop

23

2/3-way stopcock: changeover measuring side measurement / calibration loop

24

Multi-channel peristaltic pump for condensate drainage (The condensate hose pump must be stopped during calibration!)

25

IR measurement unit 1 for comparison measurement (ΔTOC-CO2 measurement)

26

Chopper chamber of the IR measuring unit 1

27

IR source of the IR measuring unit 1

28

Measuring cells CO2 of the IR measuring unit 2

29

Measuring cuvette of the IR measuring unit 2

30

Comparison cuvette of the IR measuring unit 2

31

Chopper chamber of the IR measuring unit 2

32

IR source of the IR measuring unit 2

33

Evaluation electronics / control IR spectrometer

34

Dosing pump for dosing the oxidizing agent (eg H2O2)

A

Gasausgang Ultramat

AV

Ultramat Vergleichsgas Ausgang

AW

Ausgang gestripte Wasserprobe (Standard: ca. 200 ml/h)

E

Wasserproben-Eingang (Standard: 240 ml/h)

EL

Eingang Umgebungsluft (Standardwert: 72 Nl/h)

ES

Zuleitung HCl-Säure (0,1 mol) (Standardwert: 24 ml/h)

KA

Kondensat-Ausgang

1

TC-Seite

2

TIC-Seite

3

Null-Gas-Generator

4

Mehrkanal-Schlauchpumpe zur Flüssigkeitsdosierung

5

TC-Strip-Behälter ohne Begasung

6

Reaktor der TC-Seite (Standardeinstellungen: +1000°C/T (Raum) = 2,5 min)

7

Peltier-Kühler der TC-Seite (Standardeinstellung: +0,5°C)

8

Partikel-/Säure-Filter der TC-Seite

9

Membranpumpe der TC-Seite

10

Massflowcontroller TOC-Seite (Standardwert: 24 Nl/h)

11

IR-Messeinheit 1 zur Vergleichsmessung von CO₂ (TC-ΔCO2-Messung)

12

Messzellen CO₂ der IR-Messeinheit 1

13

Mess-Küvette (TC-Seite) der IR-Messeinheit 1

14

Vergleichs-Küvette (Null-Gas-Seite) der IR-Messeinheit 1

15

Chopper-Kammer der IR-Messeinheit 1

16

IR-Quelle der IR-Messeinheit 1

17

Reaktor des Nullgas-Generators (Standardeinstellungen: +1000°/T (Raum) = 0,3 min)

18

Peltier-Kühler des Null-Gas-Generators (Standardeinstellung: +0,5°C)

19

Partikel-/Säure-Filter des Null-Gas-Generators

20

Null-Gas-Zuleitung zum TC-Reaktor (Standardwert: 24 Nl/h)

21

Null-Gas-Zuleitung zum TIC-Strip-Behälter der TIC-Seite (Standardwert: 24 Nl/h)

22

Membranpumpe des Nullgas-Generators

23

Massflowcontroller für Null-Gas-Begasung der Vergleichsküvetten (Standardwert: 2 × 24 Nl/h = 48 Nl/h)

24

Null-Gas-Zuleitung zur Vergleichs-Küvette der IR-Messeinheit 1 (Standardwert: 24 Nl/h)

25

Null-Gas-Ausgang der Vergleichs-Küvette der IR-Messeinheit 1 (Standardwert: 24 Nl/h)

26

Null-Gas-Zuleitung zur Vergleichs-Küvette der IR-Messeinheit 2 (Standardwert: 24 Nl/h)

27

Null-Gas-Ausgang der Vergleichs-Küvette der IR-Messeinheit 2 (Standardwert: 24 Nl/h)

28

TIC-Strip-Behälter der TIC-Seite mit Begasung

29

TIC-Stripgas-Zuleitung zum Reaktor der TIC-Seite (Standardwert: 24 Nl/h)

30

Reaktor der TOC-Seite (Standardeinstellungen: +1000°C/T (Raum) = 1 min)

31

Peltier-Kühler der TIC-Seite (Standardeinstellung: +0,5°C)

32

Partikel-/Säure-Filter der TIC-Seite

33

Membranpumpe der TIC-Seite

34

Massflowcontroller TIC-Seite (Standardwert: 24 Nl/h)

35

IR-Messeinheit 2 zur Vergleichsmessung von CO₂ (TIC-ΔCO2-Messung)

36

Messzellen CO₂ der IR-Messeinheit 2

37

Mess-Küvette (TIC-Seite) der IR-Messeinheit 2

38

Vergleichs-Küvette (Null-Gas-Seite) der IR-Messeinheit 2

39

Chopper-Kammer der IR-Messeinheit 2

40

IR-Quelle der IR-Messeinheit 2

41

TIC-Selbst-Kalibrier-Gas-Schleife

42

Mischbehälter der TIC-Selbst-Kalibrier-Gas-Schleife mit Rasching-Ring-

Füllung.

43

2/3-Wege-Hahn: Umschaltung Gasausgang/Kalibrierschleife TIC-Seite

44

2/3-Wege-Hahn: Umschaltung Messgas TIC-Seite/Kalibrierschleife TIC-Seite

45

Membranventil mit Rückschlagsicherung zu Parallelschaltung TIC- und Null-Gas-Küvetten bei der Kalibrierung der TIC-Seite

46

2/3-Wege-Hahn: Umschaltung Null-Gas für Vergleichsseite TIC/Kalibrierschleife TIC-Seite

47

2/3-Wege-Hahn: Umschaltung Messen TIC Ultramat Vergleichsgas Ausgang/Kalibrierschleife TIC-Seite

48

TC-Selbst-Kalibrier-Gas-Schleife

49

Mischbehälter der TC-Selbst-Kalibrier-Gas-Schleife mit Rasching-Ring-Füllung.

50

2/3-Wege-Hahn: Umschaltung Gasausgang/Kalibrierschleife TC-Seite

51

2/3-Wege-Hahn: Umschaltung Messgas TC-Seite/Kalibrierschleife TC-Seite

52

Membranventil mit Rückschlagsicherung zu Parallelschaltung TC- und Null-Gas-Küvetten bei der Kalibrierung der TC-Seite

53

2/3-Wege-Hahn: Umschaltung Null-Gas für Vergleichsseite TC/Kalibrierschleife TC-Seite

54

2/3-Wege-Hahn: Umschaltung Messen TC Ultramat Vergleichsgas Ausgang/Kalibrierschleife TC-Seite

55

IR-Spektrometer mit 2 IR-Messeinheit zur Vergleichenden Messung von CO₂-Konzentration

56

Auswerteelektronik/Steuerung IR-Spektrometer

Legend too 3 "Online H2O-TC / TIC → TOC" Ambient CO2 Compensated With Methane Compensation and Self-Calibration System with Solenoid Valve Controlled Gas Loop

A

Gas outlet Ultramat

AV

Ultramat reference gas outlet

AW

Output of stripped water sample (standard: approx. 200 ml / h)

e

Water sample input (standard: 240 ml / h)

EL

Ambient air input (default: 72 Nl / h)

IT

Feed HCl acid (0.1 mol) (default value: 24 ml / h)

KA

Condensate output

1

TC page

2

TIC page

3

Zero gas generator

4

Multi-channel peristaltic pump for liquid metering

5

TC Strip container without fumigation

6

TC side reactor (default settings: + 1000 ° C / T (space) = 2.5 min)

7

TC side peltier cooler (default: + 0.5 ° C)

8th

Particle / acid filter on the TC side

9

Diaphragm pump of the TC side

10

Massflow controller TOC page (default value: 24 Nl / h)

11

IR measurement unit 1 for comparison measurement of CO ₂ (TC-ΔCO2 measurement)

12

Measuring cells CO _{2 of} the IR measuring unit 1

13

Measuring cuvette (TC side) of the IR measuring unit 1

14

Comparative cuvette (zero gas side) of the IR measuring unit 1

15

Chopper chamber of the IR measuring unit 1

16

IR source of the IR measuring unit 1

17

Zero gas generator reactor (default settings: + 1000 ° / T (space) = 0.3 min)

18

Peltier cooler of zero-gas generator (default: + 0.5 ° C)

19

Particulate / acid filter of zero gas generator

20

Zero gas supply to the TC reactor (default: 24 Nl / h)

21

Zero gas supply to the TIC-Strip container on the TIC side (default: 24 Nl / h)

22

Diaphragm pump of the zero-gas generator

23

Mass flow controller for zero gas fumigation of the reference cuvettes (default value: 2 × 24 Nl / h = 48 Nl / h)

24

Zero gas supply to the comparative cuvette of the IR measuring unit 1 (Default: 24 Nl / h)

25

Zero gas output of the comparative cuvette of the IR measuring unit 1 (Default: 24 Nl / h)

26

Zero gas supply to the comparative cuvette of the IR measuring unit 2 (Default: 24 Nl / h)

27

Zero gas output of the comparative cuvette of the IR measuring unit 2 (Default: 24 Nl / h)

28

TIC strip container of the TIC side with fumigation

29

TIC stripping gas inlet to TIC side reactor (default: 24 Nl / h)

30

TOC side reactor (default settings: + 1000 ° C / T (space) = 1 min)

31

Peltier cooler on the TIC side (default: + 0.5 ° C)

32

Particulate / acid filter of the TIC side

33

Diaphragm pump of the TIC side

34

Mass flow controller TIC side (default value: 24 Nl / h)

35

IR measurement unit 2 for comparison measurement of CO ₂ (TIC-ΔCO2 measurement)

36

Measuring cells CO _{2 of} the IR measuring unit 2

37

Measuring cuvette (TIC side) of the IR measuring unit 2

38

Comparative cuvette (zero gas side) of the IR measuring unit 2

39

Chopper chamber of the IR measuring unit 2

40

IR source of the IR measuring unit 2

41

TIC self-calibration gas loop

42

Mixing container of the TIC self-calibrating gas loop with Rasching ring

Filling.

43

2/3-way stopcock: switching gas outlet / calibration loop TIC side

44

2/3-way stopcock: switching of sample gas TIC side / calibration loop TIC side

45

Non-return diaphragm valve for parallel connection of TIC and zero gas cuvettes when calibrating the TIC side

46

2/3-way stopcock: zero gas switching for comparison side TIC / calibration loop TIC side

47

2/3-way stopcock: Switchover Measure TIC Ultramat reference gas outlet / calibration loop TIC page

48

TC self-calibration gas loop

49

TC Auto Calibration Gas Loop Mixing Tank with Rasching Ring Filling.

50

2/3-way stopcock: changeover gas outlet / calibration loop TC side

51

2/3-way stopcock: changeover of sample gas TC side / calibration loop TC side

52

Non-return diaphragm valve for parallel connection of TC and zero gas cuvettes when calibrating the TC side

53

2/3-way stopcock: zero gas switching for comparison side TC / calibration loop TC side

54

2/3-way stopcock: switchover measurement TC Ultramat reference gas outlet / calibration loop TC side

55

IR spectrometer with 2 IR measuring unit for the comparative measurement of CO ₂ concentration

56

Evaluation electronics / control IR spectrometer

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 199365 A2 [0009]
• - DE 19547787 C1 [0011]
• - EP 780681 B1 [0011]

Cited non-patent literature

• - "Water, TOC-TO-TNb, Equipment for Analysis and Sample Preparation, Technical Information", March 2007 [0008]
• - ISO 8573-1, -2 and -5 [0012]
• - ISO 8573 [0056]
• - ISO8573-2 and -5 [0056]

Claims (23)

A method for the continuous quantitative determination of at least one oxidizable chemical compound in samples from a gaseous, liquid or solid assay medium, wherein the reaction products of the oxidation are spectrophotometrically detectable, and wherein the method comprises the steps of: a) taking a sample from the assay medium; b) dividing the sample into two equal parts; c) feeding the first part of the sample [P _ox ] to a measuring side ( 1 ) a measuring device ( 2 ) and feeding the second part of the sample [P _Vgl ] to a comparison page ( 3 ) of the measuring device ( 2 ), the measuring side ( 1 ) and the comparison page ( 2 ) have the same volume and geometry; d) oxidizing P _ox in a reactor ( 4 ) at elevated temperature to gaseous reaction products of oxidation [R _ox ] and heating P _Vgl to such a temperature in an oven ( 5 ) that the chemical compounds to be detected are gaseous; e) condensing water from R _ox and P _Vgl to establish a constant dew point; f) setting an equal and parallel mass flow for R _ox and P _Vgl ; g) supplying the R _ox mass flow to a measuring cuvette ( 6 ) and feeding the P _Vgl mass flow to a reference cuvette ( 7 ), whereby the measuring cuvette ( 6 ) and the comparison cuvette ( 7 ) of light, which is suitable for the detection of R _ox , are irradiated; h) simultaneous detection of a change in the light intensity of the incident light after passing through a measuring cuvette ( 6 ) and reference cuvette ( 7 ) in a downstream of the two cuvettes for R _ox specific measuring cell ( 8th ) to calculate a difference value of the amount of Rox between the cuvette ( 6 ) and reference cuvette ( 7 ) to build; and i) calculating the concentration of the oxidizable chemical compound in the assay medium. A method according to claim 1, characterized in that the oxidizable chemical compound is present as a trace component within the ppb region in the assay medium and is selected from the group consisting of linear, branched or cyclic hydrocarbons, in particular those having 1 to 100, preferably 1 to 60, preferably 1 to 40, particularly preferably 1 to 20 carbon atoms, and their substituted derivatives, in particular F, Br, Cl, I, S, N, P and / or O substituted derivatives; inorganic sulfur compounds, especially H ₂ S and / or SO _x ; and inorganic nitrogen compounds, especially NH ₃ , NO _x . A method according to claim 2, characterized in that hydrocarbons are detected as CO ₂ , inorganic and organic sulfur compounds as SO ₂ , and inorganic and organic nitrogen compounds as NO. Method according to claim 1 or 2, characterized that as light ultraviolet light, visible light or IR light is used. Method according to one of claims 1 to 4, characterized in that the oxidation products by NDIR spectroscopy be detected. Method according to one of claims 1 to 5, characterized in that the examination medium selected is from the group consisting of a gas, in particular also a compressed gas, preferably compressed air; Ambient air; Water, in particular sewage, sewage water or Swimming pool water; and soil samples. Method according to one of claims 1 to 6, characterized in that compressed air is used as the investigation medium and as oxidizable chemical compounds hydrocarbons are determined quantitatively, in particular those having 1 to 100, preferably 1 to 60, preferably 1 to 40, particularly preferably 1 to 20 carbon atoms; and that as R _ox CO _{2 is} detected. Method according to one of claims 1 to 6, characterized in that as the examination medium room air / exhaust air / flue gas is used and as oxidizable chemical compounds hydrocarbons are determined quantitatively, in particular those having 1 to 100, preferably 1 to 60, preferably 1 to 40, especially preferably 1 to 20 carbon atoms; and that as R _ox CO _{2 is} detected. Method according to claim 7, characterized in that the measured CO ₂ difference values in the measuring cell ( 8th ) represent a measure of the hydrocarbon content of the compressed air, the content preferably being expressed as total organic carbon content (TOC). A method according to claim 9, characterized in that the measured CO ₂ value is normalized to a standard hydrocarbon value, in particular toluene. Method according to one of claims 1 to 10, characterized in that in addition to the total organic carbon content TOC methane in one of the CO ₂ measuring cell ( 8th ) downstream methane measuring cell ( 9 ) is measured. Method according to one of claims 1 to 11, characterized in that in addition the absolute CO ₂ content of the ambient air in a separate measuring device ( 10 ) is measured. Method according to one of claims 1 to 12, characterized in that in the event that the examination medium is substantially free of oxygen, in step d) P _ox an oxidizing agent, in particular H ₂ O ₂ or pure oxygen, in particular mathematically taking into account the change in volume , is added. Process according to one of Claims 1 to 13, characterized in that the reactor ( 4 ) operates in a temperature range of 600 to 1500 ° C. Method according to one of claims 1 to 14, characterized in that in step e) water by cooling by means of Peltier cooler ( 11 . 12 ) is condensed out of the gas streams containing R _ox and P _Vgl . Method according to one of claims 1 to 15, characterized in that the gas streams containing R _ox and P _Vgl , by particle filter ( 13 . 14 ) before they get into the cuvette ( 6 ) and the comparison cuvette ( 7 ) reach; and / or the R _ox mass flow to the measuring cuvette ( 6 ) and the P _Vgl mass flow to the reference cuvette ( 7 ) by means of a mass flow limiter ( 15 . 16 ), in particular to 0.1 nl / min to 10 nl / min, preferably to about 1 nl / min. Method according to one of claims 1 to 16, characterized in that in the event that present in P _ox and / or P _Vgl to be detected oxidizable chemical compounds in the form of aerosols, in the reactor ( 4 ) or in the oven ( 5 ) an aerosol separation is provided with simultaneous combustion, wherein the reactor ( 4 ) or the furnace ( 5 ) is fed with knitted and fine filters of glass fiber, ceramic, metal wire, in particular of steel, titanium or tantalum or ceramic sintered filter materials. Method according to one of claims 1 to 17, characterized in that in the reactor ( 4 ) catalyzes the catalytic oxidation of P _ox , in particular hydrocarbons, wherein as catalysts in particular platinum / paladium or mixtures of CuO (in particular, about 40% by mass) and MnO ₂ (in particular about 50% by mass) using the cocatalysts titanium oxide, vanadium pentoxide and iron oxide (supplement to 100% by mass) or mixtures of these compounds are used. Method according to one of claims 1 to 17, characterized in that when measuring Kohlenwassertoffen (KW) in sample gas a detectability limit of about 0.001 mg KW / Nm ^{3 is} achieved. A method of continuously measuring the carbon content of an aqueous assay medium containing hydrocarbons comprising the steps of: a) taking a water sample from the assay medium; b) separating inorganic carbon from the water sample by acidification and repellency as CO ₂ ; c) supplying the inorganic carbon-free water containing only organic carbon into a vaporization and combustion chamber of a reactor ( 5 ) to a TOC measurement page ( 1 ) a measuring device ( 2 ) and supplying a pure hydrocarbon-free reference gas (zero gas) to a reactor ( 4 ) of a comparison page ( 3 ) of the measuring device ( 2 ) and the reactor ( 5 ), the measuring side ( 1 ) and the comparison page ( 3 ) have the same gas flows, the same volume and the same geometric structure; d) oxidizing the hydrocarbons in the reactor ( 5 ) at elevated temperature to CO ₂ and heating of the zero gas in reactor ( 4 ) to the same temperature; e) condensation of water vapor from the reactors ( 4 ) and ( 5 ) leaving gas streams; f) supplying the CO ₂ mass flow of the measuring side ( 1 ) to a measuring cuvette ( 6 ) and feeding the zero gas mass flow to a reference cuvette ( 7 ), whereby the measuring cuvette ( 6 ) and the comparison cuvette ( 7 ) of light which is suitable for the detection of CO ₂ are irradiated; g) simultaneous detection of a change in the light intensity of the irradiated light after passing through a measuring cuvette ( 6 ) and reference cuvette ( 7 ) in a CO ₂ -specific measuring cell downstream of the two cuvettes ( 8th ) to obtain a difference in the amount of CO ₂ between the cuvette ( 6 ) and reference cuvette ( 7 ) to build; and h) calculating the carbon content as the TOC of the water sample in the assay medium. Method according to claim 19, characterized that the water sample with a mineral acid to a pH is set by about 2.0. Method according to claim 19 or 20, characterized that step b) is omitted and thus the total carbon content (TC) as the sum of inorganic (TIC) and organic carbon content (TOC) is determined quantitatively. A method according to claim 21, characterized in that the liberated inorganic carbon by means of an additional, the TOC measuring side ( 1 ) analog TIC measurement page ( 100 ) the measuring device ( 2 ) is measured in parallel, and wherein instead of the TOC value, the TC value as a result of the measurement in the TOC measurement side ( 1 ) and determines the TOC value by subtraction from TC and TIC.