Title of Invention	"A NOVEL TOTAL ORGANIC CARBON ANALYSER"
Abstract	A novel total organic carbon analyzer characterized by at least a pair of two conventional combustion furnaces (F1 and F2) capable of operating at a temperature of 100 to 1000°C containing catalysts such as Platinum impregnated Asbestos, Ag2WO4 (silver tungsten oxide) granules, CuO2 ( copper oxide) coated quartz chips / granules or silver wool (6) in furnace (F1) for total carbon estimation and quartz chips / granules coated with 85% H3PO4 (phosoric acid)(12) in furnace (F2) for inorganic carbon estimation, the said furnaces are connected with a source of pure oxygen/air (1) through pressure regulator (2) through inlet (3/9), the said furnaces provided with a conventional temperature controller (8), sample inlets (4 and 10), the said furnaces are also connected through scrubbers/moisture and particle traps (16) capable of removing interfering gases to a colorimeter (17) consisting of a light source (18), a sample cell (19) adaptable to contain alkaline Thymolphthalein blue indicator, a sensor/detector (20), a conventional amplifier (21), LCD Display (22) and a 9V power supply, the said colorimeter is mounted on a support base(23)

Title of Invention

"A NOVEL TOTAL ORGANIC CARBON ANALYSER"

Abstract

A novel total organic carbon analyzer characterized by at least a pair of two conventional combustion furnaces (F1 and F2) capable of operating at a temperature of 100 to 1000°C containing catalysts such as Platinum impregnated Asbestos, Ag2WO4 (silver tungsten oxide) granules, CuO2 ( copper oxide) coated quartz chips / granules or silver wool (6) in furnace (F1) for total carbon estimation and quartz chips / granules coated with 85% H3PO4 (phosoric acid)(12) in furnace (F2) for inorganic carbon estimation, the said furnaces are connected with a source of pure oxygen/air (1) through pressure regulator (2) through inlet (3/9), the said furnaces provided with a conventional temperature controller (8), sample inlets (4 and 10), the said furnaces are also connected through scrubbers/moisture and particle traps (16) capable of removing interfering gases to a colorimeter (17) consisting of a light source (18), a sample cell (19) adaptable to contain alkaline Thymolphthalein blue indicator, a sensor/detector (20), a conventional amplifier (21), LCD Display (22) and a 9V power supply, the said colorimeter is mounted on a support base(23)

Full Text	The present invention relates to a novel Total organic Carbon Analyser. The invention particularly leads to a transportable, low-cost, indigenous, application specific Total Organic Carbon Analyzer (TOCA) based on Colorimetric principle using novel indicator dye. Charcterisation of industrial or municipal wastewater for organic pollution load is essential to design, monitor or evaluate wastewater treatment plants. Therefore, this invention is useful in the fields of sewage/industrial waste characterization, monitoring influents and effluents of wastewater treatment plants, estimation of organic pollution load in the leachates from solid waste or sludge disposal sites, etc. and to find out pollution load due to organic carbon present in such environmental aqueous samples. The invention can also be used to measure Total Carbon (TC) and Inorganic Carbon (1C) and Total Organic Carbon (TOC) components in wastes from hydrocarbons (petroleum, petrochemical) industry, chemical industry, pharmaceutical industry, food products and sugar industry, dairies, distilleries, tanneries, etc. Rapid analysis will facilitate research and pilol plant studies to control the product loss due to leakage or inefficient plant operation. Transportability of the instrument will help field studies on municipal and industrial wastewaters at the site. Reference may be made to following patents: (Table Removed) These references clearly indicates that the instrument uses conductivity detector, the drawbacks are need for very high purity water and non transportability. Reference may be made to patents listed below: (Table Removed) These references clearly indicates that the instrument uses non-destructive infra red (NDIR) detector, the drawbacks are non transportability. Reference may be made to instrument already marketed wherein the instrument uses Flame lonisation detector the drawbacks are need for hydrogen and non transportability. To the best of our knowledge total organic carbon analyser incorporating novei colorimetric method using non-conventional indicator is not reported yet. The Main Object of the present invention is to provide Total Organic Carbon Analyser based on Novel Colorimetric Detector' which obviates the drawbacks as detailed above Another object of the present invention is to provide an application specific instrument to determine total organic pollution load in influents and effluents of wastewater treatment plants, leachates or polluted surface waters Still another of the present invention is to provide low cost, simple instrument using low cost consumables to determine total organic carbon in range suitable for aqueous environmental samples Yet another object of the present invention is to provide an instrument based on new technique employing colorimetric principle and using novel color indicating dye to determine inorganic carbon, total carbon and total organic carbon in range 10 to 1000 ppm or above Yet another of the present invention is to provide transportable instrument for field use to monitor and study industrial and municipal wastewaters for pollution load and loss of resources due to inefficient processes or leakages In the drawings accompanying this specification, Figure 1 represents Total Organic Carbon (TOC) Analyser and figure 2 represents novel colorimeter. Accordingly the present invention provides, a novel total organic carbon analyzer characterized by one or more pair(s) of two conventional combustion furnaces (Fl and F2) capable of operating at a temperature of 100 to 1000°C containing catalysts such as Platinum impregnated Asbestos, Ag2WO4 (silver tungsten oxide) granules, CuO2 ( copper oxide) coated quartz chips / granules or silver wool (6) in furnace (Fl) for total carbon estimation and quartz chips / granules coated with 85% HsPO4 (phosoric acid)(12) in furnace (F2) for inorganic carbon estimation, the said furnaces are connected with a source of pure oxygen/air (1) through pressure regulator (2) through inlet (3/9), the said furnaces provided with a conventional temperature controller (8), sample inlets (4 and 10), the said furnaces are also connected through scrubbers/moisture and particle traps (16) capable of removing interfering gases to a colorimeter (17) consisting of a light source (18), a sample cell (19) adaptable to contain alkaline Thymolphthalein blue indicator, a sensor/detector (20), a conventional amplifier (21), LCD Display (22) and a 9V power supply, the said colorimeter is mounted on a support base(23). Total Organic Carbon Analyzer of the present invention is based on Novel Colorimetric Detector which employs colorimetric principle using novel color indicating dye to determine inorganic carbon, total carbon and total organic carbon in for the aqueous environmental samples. The Total Organic Carbon Analyser based on Novel Colorimetric Detector', an application specific invention, has range of 10 ppm to 1,000 ppm (or above) which is necessary and sufficient for analysis organic pollution load in Influents and effluents of municipal and industrial wastewater treatment plants, leachates, or polluted surface waters The Total Organic Carbon Analyser based on Novel Colorimetric Detector1 leads to transportable analyzer for field use to study industrial and municipal wastewaters for organic pollution load and loss of resources/products due to inefficient processes or leakages at the sites The Total Organic Carbon Analyser based on Novel Colorimetric Detector' simple, indigenous, non-conventional, easy to operate and low cost instrument employing easily available low cost chemicals The Total Organic Carbon Analyser based on Novel Colorimetric Detector1 suitable for on line or off line measurements Combustion furnaces and temperature controllers are property designed to suit the temperature ranges 100° to 200° C and 700° to 1000° C respectively for slow increase of the temperature of the combustion furnace / tube upto set points within +/-10°C. The inlet of the combustion furnace (F1/F2) is supplied with carrier pure oxygen/air(3/9). The oxygen flow rate is controlled and adjusted to 60 ml/min by needle valve. The ceramic/quartz combustion tubes contains quartz granule coated with 85% Phosphoric Acid and Platinum impregnated asbestos + copper oxide + silver tungsten granules + silver gauge respectively. 10 to 100 ul of sample injected by device such as hypodermic syringes in either furnace, which catalytically oxidises to convert total carbon or only inorganic carbon into CO2. Interfering gases can be removed by using scrubbers or converting them to the non-interfering products in the furnace. This is carried through moisture and particulate traps to reaction cell of colorimeter. The sample/reaction cell is designed with adequate path length of 2 Cm and to accommodate 0.5 ml absorbing solution (such as caustic potash solution in the range of 10-4 to 10-5 molar containing dye like Thymolphthalein blue as indicator). On either sides of sample cell a light source and a detector are located. The gas is allowed to react slowly with this solution for 5 minutes. As the gas passes through and reacts with the solution the color/absorbance of the solution reduces from dark blue to colorless transparent solution. This change in color (decoloration) allows more light to pass through proportional to the concentration of the inorganic/total carbon in the samples. The sensitive detector calibrated using standard reference materials detects in-situ any minute change. This detected change in the form of signal is further processed by a three-stage amplifier circuit and displayed on the 3-1/2 digit LCD. The large electronic back-off is provided to adjust output to zero for blank solution. TOC analysers generally employ NDIR, conductivity or Fl detectors. These detectors are cumbersome and/or expensive. Implementation of non-conventional colorimetric detector employing novel indicator leads to simple low-cost and transportable TOC analyser suitable for wastewater characterisation. Total Carbon or Total Organic Carbon in wastewaters is estimated by converting inorganic or total carbon to Carbon Dioxide by catalytic combustion. CO2 carried to sample/reaction cell of colorimeter containing aqueous solution of caustic potash and color dye as indicator reacts with it. Absorbance of the solution changes as the carbon in the sample increases. Thus Inorganic/Total Carbon can be determined colorimetricaly after calibration of detector using standard reference materials. Difference between TC & 1C gives TOC. The range 10 to 1,000 ppm of TOC, which is most critical for wastewater and other environmental samples, is easily amenable to this detector. Samples with higher concentration of carbon can be analysed after dilution. The same instrument can also be used for analysis of industrial effluents, leachates, sludges, and other environmental samples. Catalytic combustion at 150° C converts only inorganic carbon to CO2 whereas at 950° C Total Carbon can be converted to CO2. The present invention consists of an instrument for determining total organic carbon in environmental samples in range of 10 ppm to 1,000 ppm and above employing low-cost and simple colorimetric detection technique. The inorganic carbon in the sample (50 ul) injected in fumace is combusted at 150° C in the presence of oxygen as carrier and quartz chips coated with 85% Phosphoric Acid as catalysts to generate carbon dioxide. Water vapours and particles are removed by moisture and particle trap. The carbon dioxide is carried in reaction cell of specially designed colorimeter, which holds aqueous solution of potassium hydroxide in the range of 10-4 to 10-5 molar to absorbs CO2 and Thymolphthalein Blue used as indicator color dye. Color of the solution is reduced from dark blue to colorless transparent solution due to carbon dioxide absorbed in aqueous solution. The change in color is determined using colorimeter. Decoloration of the solution is proportional to Inorganic Carbon (IC) in the sample for the range 10 to 1,000 ppm. Subsequently total carbon in the 50 ul sample injected and combusted in another furnace at 900° to 950° C in the presence of oxygen as carrier and R impregnated asbestos, Ag2WO4 granules, CuO2 coated quartz chips, Silver wool, etc generate carbon dioxide and convert interfering gasses to non-interfering ones. Water vapours are removed as described earlier. The carbon dioxide is carried in same reaction cell after adjusting zero (back-off). Further decoloration of the solution is proportional to total carbon (TC) in the sample. The difference (TC-IC) gives TOC. The higher concentrations of total carbon can be determined by diluting the samples appropriately. In samples known to have negligible inorganic carbon, single injection in 950° C furnace gives TOC. The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention. It describes actual laboratory experiment The temperature of closed 1C furnace was allowed to reach 150°C with flow of contamination free oxygen of 60 ml/min. The colorimeter with sample-cum-reaction cell of volume 0.5 ml and 2 cm path length was employed. The transparency of the fresh 10-4 molar potassium hydroxide aqueous solution with Thymolphthalein Blue as indicator color dye in the sample cell of colorimeter is adjusted to zero. Filtered 50 µl standard solution of 10 ppm 1C was injected from the top of the combustion tube using hypodermic syringe. The combustion gases along with residual oxygen was passed through the scrubbers and allowed to flow and react with the liquid absorbent in the sample cell. After absorption of CO2, again the transparency of absorbent is checked and recorded. The experiment is repeated for three to four known reference standards with IC between 10 to 1000 ppm using fresh absorbent in the sample cell. The calibration curve was plotted (1C vs Colorimetric reading in AU). Then temperature of dosed TC furnace was allowed to reach 950°C with flow of contamination free oxygen of 60 ml/min. The experiment was repeated for standard solutions of 10 to 1000 ppm TC using fresh absorbent in the sample cell. The calibration curve was plotted (TC vs Colorimetric reading in AU) (Table Removed) A 50 µl unknown aqueous sample with 10 to 1,000 ppm TC was injected on the top of the IC combustion tube. The combustion gases atongwith oxygen is allowed to react in the sample cell. The transparency of the color dye is adjusted to zero before the gas reaction. After gas reaction again the transparency is recorded and IC calculated using calibration curve. The transparency of the color dye is adjusted to zero again and 50 ul sample was injected on the top of the TC combustion tube. The combustion gases alongwith oxygen is allowed to react in the sample cell and after reaction again the transparency is recorded and TC calculated using calibration curve. TOC is obtained as difference between TC and IC. Organic pollution load in wastewaters can be determined using novel TOC analyser employing non-conventional colorimetric detector. Absorbance of the solution reduces as the dissolved carbon dioxide increases which can be correlated with Total Organic Carbon. The analyser based on colorimetric principle employing color dye such as Thymolphthalein Blue in potassium hydroxide aqueous solution, which is employed for absorbing carbon dioxide in colorimetric detector, can be used to determine Total Carbon, Total Inorganic Carbon and Total Organic Carbon in the range of 10 to 1,000 ppm. This can be fruitfully employed to analyse environmental sample such as waste-water, sewage and industrial effluents, etc which contains organic carbon in the range of 10 to 1,000 ppm. The method can be used to determine higher concentration of TOC by appropriate dilution. TOC Analysers generally use expensive NDIR detectors or cumbersome conductivity detectors or flame ionisation detectors. This low-cost and indigenous invention implements novel colorimetric detector employing non-conventional indicator which leads to transportable TOC Analyser for measurement of pollution load in environmental samples for relevant ranges. Since this is based on colorimetric principle it can be used as off line and online monitoring instrument. The main advantages of the present invention are: The development leads to simple, indigenous, non-conventional, easy to operate and low cost TOC Analyser employing easily available low cost chemicals for routine analysis in the field of aqueous environmental samples. It can be used to determine Influents and effluents of wastewater treatment plants, leachates or polluted surface waters for their organic pollution load. The invention employs colorimetric principle using novel color indicating dye for determine inorganic carbon, total carbon and total organic carbon in range 10 to 1000 ppm or above The application specific invention has range of 10 ppm to 1,000 ppm (or above) for the aqueous samples which is necessary and sufficient for analysis organic pollution load in municipal and industrial waste waters, leachates, etc. Present invention leads to transportable analyzer for field use to study industrial and municipal wastewaters for pollution load and loss of resources due to inefficient processes or leakages. The invention can be used for determining TOC in on line or off line mode. We Claim: 1. A novel total organic carbon analyzer characterized by one or more pair(s) of two conventional combustion furnaces (Fl and F2) capable of operating at a temperature of 100 to 1000°C containing catalysts such as Platinum impregnated Asbestos, Ag2WO4 (silver tungsten oxide) granules, CuO2 ( copper oxide) coated quartz chips / granules or silver wool (6) in furnace (F1) for total carbon estimation and quartz chips / granules coated with 85% H3PO4 (phosoric acid)(12) in furnace (F2) for inorganic carbon estimation, the said furnaces are connected with a source of pure oxygen/air (1) through pressure regulator (2) through inlet (3/9), the said furnaces provided with a conventional temperature controller (8), sample inlets (4 and 10), the said furnaces are also connected through scrubbers/moisture and particle traps (16) capable of removing interfering gases to a colorimeter (17) consisting of a light source (18), a sample cell (19) adaptable to contain alkaline Thymolphthalein blue indicator, a sensor/detector (20), a conventional amplifier (21), LCD Display (22) and a 9V power supply, the said colorimeter is mounted on a support base(23). 2. A novel total organic carbon analyzer substantially as herein described with reference to the examples and drawings accompanying thee specifications.

Full Text

The present invention relates to a novel Total organic Carbon Analyser.
The invention particularly leads to a transportable, low-cost, indigenous, application specific Total Organic Carbon Analyzer (TOCA) based on Colorimetric principle using novel indicator dye.
Charcterisation of industrial or municipal wastewater for organic pollution load is essential to design, monitor or evaluate wastewater treatment plants. Therefore, this invention is useful in the fields of sewage/industrial waste characterization, monitoring influents and effluents of wastewater treatment plants, estimation of organic pollution load in the leachates from solid waste or sludge disposal sites, etc. and to find out pollution load due to organic carbon present in such environmental aqueous samples.
The invention can also be used to measure Total Carbon (TC) and Inorganic Carbon (1C) and Total Organic Carbon (TOC) components in wastes from hydrocarbons (petroleum, petrochemical) industry, chemical industry, pharmaceutical industry, food products and sugar industry, dairies, distilleries, tanneries, etc. Rapid analysis will facilitate research and pilol plant studies to control the product loss due to leakage or inefficient plant operation.
Transportability of the instrument will help field studies on municipal and industrial wastewaters at the site.
Reference may be made to following patents:

(Table Removed)
These references clearly indicates that the instrument uses conductivity detector, the drawbacks are need for very high purity water and non transportability.
Reference may be made to patents listed below:

(Table Removed)
These references clearly indicates that the instrument uses non-destructive infra red (NDIR) detector, the drawbacks are non transportability.
Reference may be made to instrument already marketed wherein the instrument uses Flame lonisation detector the drawbacks are need for hydrogen and non transportability.
To the best of our knowledge total organic carbon analyser incorporating novei colorimetric method using non-conventional indicator is not reported yet.
The Main Object of the present invention is to provide Total Organic Carbon Analyser based on Novel Colorimetric Detector' which obviates the drawbacks as detailed above
Another object of the present invention is to provide an application specific instrument to determine total organic pollution load in influents and effluents of wastewater treatment plants, leachates or polluted surface waters
Still another of the present invention is to provide low cost, simple instrument using low cost consumables to determine total organic carbon in range suitable for aqueous environmental samples
Yet another object of the present invention is to provide an instrument based on new technique employing colorimetric principle and using novel color indicating dye to determine inorganic carbon, total carbon and total organic carbon in range 10 to 1000 ppm or above
Yet another of the present invention is to provide transportable instrument for field use to monitor and study industrial and municipal wastewaters for pollution load and loss of resources due to inefficient processes or leakages
In the drawings accompanying this specification, Figure 1 represents Total Organic Carbon (TOC) Analyser and figure 2 represents novel colorimeter.
Accordingly the present invention provides, a novel total organic carbon analyzer characterized by one or more pair(s) of two conventional combustion furnaces (Fl and F2) capable of operating at a temperature of 100 to 1000°C containing catalysts such as Platinum impregnated Asbestos, Ag2WO4 (silver tungsten oxide) granules, CuO2 ( copper oxide) coated quartz chips / granules or silver wool (6) in furnace (Fl) for total carbon estimation and quartz chips / granules coated with 85% HsPO4 (phosoric acid)(12) in furnace (F2) for inorganic carbon estimation, the said furnaces are connected with a source of pure oxygen/air (1) through pressure regulator (2) through inlet (3/9), the said furnaces provided with a conventional temperature controller (8), sample inlets (4 and 10), the said furnaces are also connected through scrubbers/moisture and particle traps (16) capable of removing interfering gases to a colorimeter (17) consisting of a light source (18), a sample cell (19) adaptable to contain alkaline Thymolphthalein blue indicator, a sensor/detector (20), a conventional amplifier (21), LCD Display (22) and a 9V power supply, the said colorimeter is mounted on a support base(23).
Total Organic Carbon Analyzer of the present invention is based on Novel Colorimetric Detector which employs colorimetric principle using novel color indicating dye to determine inorganic carbon, total carbon and total organic carbon in for the aqueous environmental samples.

The Total Organic Carbon Analyser based on Novel Colorimetric Detector', an application specific invention, has range of 10 ppm to 1,000 ppm (or above) which is necessary and sufficient for analysis organic pollution load in Influents and effluents of municipal and industrial wastewater treatment plants, leachates, or polluted surface waters
The Total Organic Carbon Analyser based on Novel Colorimetric Detector1 leads to transportable analyzer for field use to study industrial and municipal wastewaters for organic pollution load and loss of resources/products due to inefficient processes or leakages at the sites
The Total Organic Carbon Analyser based on Novel Colorimetric Detector' simple, indigenous, non-conventional, easy to operate and low cost instrument employing easily available low cost chemicals
The Total Organic Carbon Analyser based on Novel Colorimetric Detector1 suitable for on line or off line measurements
Combustion furnaces and temperature controllers are property designed to suit the temperature ranges 100° to 200° C and 700° to 1000° C respectively for slow increase of the temperature of the combustion furnace / tube upto set points within +/-10°C. The inlet of the combustion furnace (F1/F2) is supplied with carrier pure oxygen/air(3/9). The oxygen flow rate is controlled and adjusted to 60 ml/min by needle valve. The ceramic/quartz combustion tubes contains quartz granule coated with 85% Phosphoric Acid and Platinum impregnated asbestos + copper oxide + silver tungsten granules + silver gauge respectively. 10 to 100 ul of sample injected by device such as hypodermic syringes in either furnace, which catalytically oxidises to convert

total carbon or only inorganic carbon into CO2. Interfering gases can be removed by using scrubbers or converting them to the non-interfering products in the furnace. This is carried through moisture and particulate traps to reaction cell of colorimeter. The sample/reaction cell is designed with adequate path length of 2 Cm and to accommodate 0.5 ml absorbing solution (such as caustic potash solution in the range of 10-4 to 10-5 molar containing dye like Thymolphthalein blue as indicator). On either sides of sample cell a light source and a detector are located. The gas is allowed to react slowly with this solution for 5 minutes. As the gas passes through and reacts with the solution the color/absorbance of the solution reduces from dark blue to colorless transparent solution. This change in color (decoloration) allows more light to pass through proportional to the concentration of the inorganic/total carbon in the samples. The sensitive detector calibrated using standard reference materials detects in-situ any minute change. This detected change in the form of signal is further processed by a three-stage amplifier circuit and displayed on the 3-1/2 digit LCD. The large electronic back-off is provided to adjust output to zero for blank solution.
TOC analysers generally employ NDIR, conductivity or Fl detectors. These detectors are cumbersome and/or expensive. Implementation of non-conventional colorimetric detector employing novel indicator leads to simple low-cost and transportable TOC analyser suitable for wastewater characterisation. Total Carbon or Total Organic Carbon in wastewaters is estimated by converting inorganic or total carbon to Carbon Dioxide by catalytic combustion. CO2 carried to sample/reaction cell of colorimeter containing aqueous solution of caustic potash and color dye as indicator

reacts with it. Absorbance of the solution changes as the carbon in the sample increases. Thus Inorganic/Total Carbon can be determined colorimetricaly after calibration of detector using standard reference materials. Difference between TC & 1C gives TOC. The range 10 to 1,000 ppm of TOC, which is most critical for wastewater and other environmental samples, is easily amenable to this detector. Samples with higher concentration of carbon can be analysed after dilution. The same instrument can also be used for analysis of industrial effluents, leachates, sludges, and other environmental samples. Catalytic combustion at 150° C converts only inorganic carbon to CO2 whereas at 950° C Total Carbon can be converted to CO2.
The present invention consists of an instrument for determining total organic carbon in environmental samples in range of 10 ppm to 1,000 ppm and above employing low-cost and simple colorimetric detection technique.
The inorganic carbon in the sample (50 ul) injected in fumace is combusted at 150° C in the presence of oxygen as carrier and quartz chips coated with 85% Phosphoric Acid as catalysts to generate carbon dioxide. Water vapours and particles are removed by moisture and particle trap. The carbon dioxide is carried in reaction cell of specially designed colorimeter, which holds aqueous solution of potassium hydroxide in the range of 10-4 to 10-5 molar to absorbs CO2 and Thymolphthalein Blue used as indicator color dye. Color of the solution is reduced from dark blue to colorless transparent solution due to carbon dioxide absorbed in aqueous solution. The change in color is determined using colorimeter. Decoloration of the solution is proportional to Inorganic Carbon (IC) in the sample for the range 10 to 1,000
ppm. Subsequently total carbon in the 50 ul sample injected and combusted in another furnace at 900° to 950° C in the presence of oxygen as carrier and R impregnated asbestos, Ag2WO4 granules, CuO2 coated quartz chips, Silver wool, etc generate carbon dioxide and convert interfering gasses to non-interfering ones. Water vapours are removed as described earlier. The carbon dioxide is carried in same reaction cell after adjusting zero (back-off). Further decoloration of the solution is proportional to total carbon (TC) in the sample. The difference (TC-IC) gives TOC. The higher concentrations of total carbon can be determined by diluting the samples appropriately. In samples known to have negligible inorganic carbon, single injection in 950° C furnace gives TOC.
The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention. It describes actual laboratory experiment
The temperature of closed 1C furnace was allowed to reach 150°C with flow of contamination free oxygen of 60 ml/min. The colorimeter with sample-cum-reaction cell of volume 0.5 ml and 2 cm path length was employed. The transparency of the fresh 10-4 molar potassium hydroxide aqueous solution with Thymolphthalein Blue as indicator color dye in the sample cell of colorimeter is adjusted to zero. Filtered 50 µl standard solution of 10 ppm 1C was injected from the top of the combustion tube using hypodermic syringe. The combustion gases along with residual oxygen was passed through the scrubbers and allowed to flow and react with the liquid absorbent in the sample cell. After absorption of CO2, again the transparency of absorbent is

checked and recorded. The experiment is repeated for three to four known reference standards with IC between 10 to 1000 ppm using fresh absorbent in the sample cell. The calibration curve was plotted (1C vs Colorimetric reading in AU).
Then temperature of dosed TC furnace was allowed to reach 950°C with flow of contamination free oxygen of 60 ml/min. The experiment was repeated for standard solutions of 10 to 1000 ppm TC using fresh absorbent in the sample cell. The calibration curve was plotted (TC vs Colorimetric reading in AU)

(Table Removed)
A 50 µl unknown aqueous sample with 10 to 1,000 ppm TC was injected on the top of the IC combustion tube. The combustion gases atongwith oxygen is allowed to react in the sample cell. The transparency of the color dye is adjusted to zero before the gas reaction. After gas reaction again the transparency is recorded and IC calculated using calibration curve. The transparency of the color dye is adjusted to zero again and 50 ul sample was injected on the top of the TC combustion tube. The combustion gases
alongwith oxygen is allowed to react in the sample cell and after reaction again the transparency is recorded and TC calculated using calibration curve. TOC is obtained as difference between TC and IC.
Organic pollution load in wastewaters can be determined using novel TOC analyser employing non-conventional colorimetric detector. Absorbance of the solution reduces as the dissolved carbon dioxide increases which can be correlated with Total Organic Carbon.
The analyser based on colorimetric principle employing color dye such as Thymolphthalein Blue in potassium hydroxide aqueous solution, which is employed for absorbing carbon dioxide in colorimetric detector, can be used to determine Total Carbon, Total Inorganic Carbon and Total Organic Carbon in the range of 10 to 1,000 ppm. This can be fruitfully employed to analyse environmental sample such as waste-water, sewage and industrial effluents, etc which contains organic carbon in the range of 10 to 1,000 ppm. The method can be used to determine higher concentration of TOC by appropriate dilution.
TOC Analysers generally use expensive NDIR detectors or cumbersome conductivity detectors or flame ionisation detectors. This low-cost and indigenous invention implements novel colorimetric detector employing non-conventional indicator which leads to transportable TOC Analyser for measurement of pollution load in environmental samples for relevant ranges.
Since this is based on colorimetric principle it can be used as off line and online monitoring instrument.
The main advantages of the present invention are:
The development leads to simple, indigenous, non-conventional, easy to operate and low cost TOC Analyser employing easily available low cost chemicals for routine analysis in the field of aqueous environmental samples. It can be used to determine Influents and effluents of wastewater treatment plants, leachates or polluted surface waters for their organic pollution load.
The invention employs colorimetric principle using novel color indicating dye for determine inorganic carbon, total carbon and total organic carbon in range 10 to 1000 ppm or above
The application specific invention has range of 10 ppm to 1,000 ppm (or above) for the aqueous samples which is necessary and sufficient for analysis organic pollution load in municipal and industrial waste waters, leachates, etc.
Present invention leads to transportable analyzer for field use to study industrial and municipal wastewaters for pollution load and loss of resources due to inefficient processes or leakages.
The invention can be used for determining TOC in on line or off line mode.

We Claim:
1. A novel total organic carbon analyzer characterized by one or more pair(s) of two
conventional combustion furnaces (Fl and F2) capable of operating at a temperature of
100 to 1000°C containing catalysts such as Platinum impregnated Asbestos, Ag2WO4
(silver tungsten oxide) granules, CuO2 ( copper oxide) coated quartz chips / granules or
silver wool (6) in furnace (F1) for total carbon estimation and quartz chips / granules
coated with 85% H3PO4 (phosoric acid)(12) in furnace (F2) for inorganic carbon
estimation, the said furnaces are connected with a source of pure oxygen/air (1) through
pressure regulator (2) through inlet (3/9), the said furnaces provided with a conventional
temperature controller (8), sample inlets (4 and 10), the said furnaces are also connected
through scrubbers/moisture and particle traps (16) capable of removing interfering gases
to a colorimeter (17) consisting of a light source (18), a sample cell (19) adaptable to
contain alkaline Thymolphthalein blue indicator, a sensor/detector (20), a conventional
amplifier (21), LCD Display (22) and a 9V power supply, the said colorimeter is
mounted on a support base(23).
2. A novel total organic carbon analyzer substantially as herein described with reference to
the examples and drawings accompanying thee specifications.

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Patent Number

218314

Indian Patent Application Number

329/DEL/2000

PG Journal Number

22/2008

Publication Date

30-May-2008

Grant Date

31-Mar-2008

Date of Filing

28-Mar-2000

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESARCH

Applicant Address

RAFI MARG, NEW DELHI 110 001 INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	BHIMRAO ZAPARAJI ALONE	INSTRUMENTATION DIVISION, NEERI, NEHRU MARG, NAGPUR- 440020, INDIA.
2	VIVEK KESHOORAO KONDAWAR	INSTRUMENTATION DIVISION, NEERI, NEHRU MARG, NAGPUR- 440020, INDIA.
3	VILAS MOTIRAM SHINDE	INSTRUMENTATION DIVISION, NEERI, NEHRU MARG, NAGPUR- 440020, INDIA.

PCT International Classification Number

GO1N 7/08

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA