Patent Description:
More specifically, the disclosure relates to testing for residual organic compounds in a water sample. One such application for such tests are for testing water samples used in steam boilers for the presence of certain organic compounds, those existing naturally or those added. Various organic compounds may be added to water supplies for various purpose. For instance, some organic compounds can be added to a water supply to help prevent corrosion of metallic parts or systems in which the water supply comes into contact. One such organic compound with anti- corrosion properties is the proprietary organic compound sold as Anodamine® by Anodamine Inc. which can be used to treat steam water cycles in steam boilers or other industrial applications. It can be beneficial to periodically test the residual amount of organic compound additives to the water supply in such industrial systems to ensure a proper or desired amount of the organic compound additive is contained within the water supply.

Conventional testing methods include introducing indicator reagents into a liquid sample that are designed to react with the desired organic chemical component which is the subject of the test. The indicator reagent can produce a residual color or a component as a reaction between the indicator reagent and the chemical of interest. Incremental amounts of the indicator reagent are added to the sample until the colored compound is visible in the testing sample, indicating the presence of the compound. The indicator reagent added forms a colored complex which is proportional in a linear manner to the component of interest. These tests are based upon visibly detecting the intensity of the compound formed between the indicator reagent added and the substance of interest, and certain assumptions based on the relationship between the amount of reagent added and the concentration of the chemical of interest within the sample, such tests may be qualitative in nature, exposed to significant interferences and estimates at best.

<CIT> describes a UV absorption method which is based upon the measurement of the absorbance of a component of corrosion inhibitor formulation to monitor the concentration of a water-soluble corrosion inhibitor formulation in the water of an aqueous system.

<CIT> describes that an analyte concentration can be measured at an electrochemical detector using a waveform that includes a reductive voltage. The waveform may include three or four different voltages, in which at least one of the voltage values is reductive. One or more current or charge values can be measured during at least part of a reductive voltage portion of the waveform. The analyte concentration can be calculated based on the measured one or more current or charge values.

<CIT> describes a device and method for analyzing the concentration of organic matter in real time, which determines the purity of pure and ultrapure purified water (manufactured water), using spectrophotometry to analyze absorbance at a UV wavelength of <NUM> as a substitute for Total Organic Carbon (TOC) measurement and analysis.

<NPL>, describes a method for the determination of petroleum hydrocarbons in discharge from oil production facilities using ultraviolet spectroscopy. The concentration of oil in the sample was calculated from a Lambert-Beer plot at <NUM>.

<CIT> describes an ultra-violet absorbance-based monitor for on-line monitoring of organic pollution in water at on-site locations by measuring the reduction in UV light passed through a sample.

<CIT> describes a water treating apparatus including an ion-exchange resin-filled section and a softening section disposed integrally with a vacuum deaerating membrane section so as to allow gases to pass through the membrane while a liquid is prevented from passing therethrough.

<CIT> describes apparatus and methods for the measurement of total organic carbon, total inorganic carbon, total carbon and total heterorganic carbon of deionized water.

What is needed then are improvements in testing for organic chemicals in water/liquid test samples.

This Brief Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description.

The present invention is defined in the independent claims <NUM> and <NUM>.

A method of testing a water sample for at least one anti-corrosion saturated and/or unsaturated aliphatic nitrogen containing organic compound, and a system for measuring the concentration of at least one anti-corrosion saturated and/or unsaturated aliphatic nitrogen containing organic compounds in a water sample from a thermal power system or other steam water cycle, are disclosed in the independent claims.

Some optional and/or preferable features are disclosed in the dependent claims.

One objective of the present disclosure is to accurately and efficiently detect the presence of organic compounds in water/liquid samples without being required to add indicator reagents, such water samples including but not limited to water samples from steam boilers.

Another objective of the present disclosure is to measure the presence of organic compounds in a liquid sample using spectrophotometry techniques across the UV light spectrum.

Another objective of the present disclosure is to remove interferences and contaminants from a liquid sample before the sample is tested for the presence of an organic compound using spectrophotometry techniques.

Numerous other objects, advantages and features of the present disclosure will be readily apparent to those of skill in the art upon a review of the following drawings and description of a preferred embodiment.

In the drawings, not all reference numbers are included in each drawing, for the sake of clarity. In addition, positional terms such as "upper," "lower," "side," "top," "bottom," etc. refer to the apparatus when in the orientation shown in the drawing. A person of skill in the art will recognize that the apparatus can assume different orientations when in use.

This method and systems disclosed herein allow users to test a liquid or water sample for the presence of organic compounds of interest. The method and systems disclosed herein can be particularly useful in the thermal power industry or any user that uses steam boilers for the purpose of producing steam or condensate to quantitatively measure the residual amount of desired organic components in the water, water vapor, or steam used within such systems. The method can not only be used to measure residual quantities of a specific organic compound, such as the proprietary anti-corrosion chemical sold under the name Anodamine®, but also to measure any other naturally occurring organic compounds, like humic acids and polysaccharides, or the total organic compounds (TOC) present in the sample. The method, whilst initially developed for the measurement of the organic, surface-active metal corrosion inhibiting product (Anodamine®), is tailored to allow for the measurement of most saturated and unsaturated organics, especially those with aliphatic long-chain nitrogen-containing functional groups.

The methods and systems of the present disclosure can help remove the need for reagents, can be low-cost, and can help provide a rapid determination of the presence of organic components in a water or liquid sample. The methods and systems disclosed herein are an industry-first methodology for the measurement of organic components, specifically with light in the UV spectrum (<NUM> - <NUM> range). The wavelength selected for the test can be based upon the organic type, architecture and bond functionality of the target organic component. Each organic structure would require its own UV wavelength calibration curve to calculate concentrations of the specific organic compound in a test water or liquid sample based on measured light absorption by the organic compound in the sample.

The method allows for the residual measurement of both the Anodamine® high-pressure product grade as well as the Anodamine® low-pressure product grade. The method was conducted, optimized, and validated using specific hardware and software, discussed below. The method was also validated using a specific analytical instrumentational configuration and technique as detailed herein.

One aspect of the present disclosure, as shown in <FIG> is a system <NUM> for measuring the concentration of an organic compound in a water sample <NUM>, the system <NUM> including a pump <NUM> for pumping liquid from the liquid sample <NUM> through the system <NUM>; an ion exchange column <NUM> in fluid communication with the pump <NUM>; and a spectrophotometer <NUM> in fluid communication with the ion exchange column <NUM>, the spectrophotometer <NUM> configured to transmit light <NUM> having a wavelength of about <NUM> nanometers to <NUM> nanometers into the liquid sample <NUM> and measure the absorption/transmission of the light <NUM> by the organic compound in the liquid sample <NUM>. Transmitting light <NUM> having a wavelength of between about <NUM> and <NUM> nanometers can mean that the spectrophotometer <NUM> can be configured to transmit any singular wavelength of light within the range of <NUM> to <NUM> nanometers, any subsets of wavelengths of light between <NUM> and <NUM> nanometers, all wavelengths of light between <NUM> and <NUM> nanometers, or bands of light wherein a portion of the band of light has wavelengths between <NUM> and <NUM> nanometers and a portion of the band of light that is not between <NUM> and <NUM> nanometers. In other words, at least a portion of the light transmitted into the liquid sample <NUM> can have wavelengths of between about <NUM> and <NUM> nanometers. The specific wavelengths transmitted through the liquid sample <NUM> can be tailored depending on the relevant light absorption spectrum of the organic compound of interest.

In some embodiments, the system <NUM> can include a first vacuum degasser channel <NUM> in fluid communication between the pump <NUM> and the ion exchange column <NUM> such that the ion exchange column <NUM> is in fluid communication with the pump <NUM> via the first vacuum degasser channel <NUM>. The system <NUM> includes a second vacuum degasser channel <NUM> in fluid communication between the ion exchange column <NUM> and the spectrophotometer <NUM> such that the ion exchange column <NUM> is in fluid communication with the spectrophotometer <NUM> via the second vacuum degasser channel <NUM>.

A certain instrumentational configuration, quality of optics and measurement sensitivity are required for the successful application and method sensitivity that is needed to measure most saturated and unsaturated organics (especially those with aliphatic, long-chain, nitrogen-containing functionalities). The method has been specifically adapted to the Mettler Toledo UV5Bio spectrophotometer, utilizing the additional Mettler Toledo FillPalMini peristaltic pump and optical quartz <NUM> flow-through cell, though any suitable pump/aspirator device and spectrophotometer could be utilized depending on the organic compound of interest. Sample preparation can include the use of a suitably sized ion exchange column <NUM>, and in some embodiments the ion exchange column <NUM> can include a strong acid, cation-charged resin column for removing cation contaminants including but not limited to sodium, magnesium, calcium, etc. with inline vacuum degasser channels. Depending on the contaminants trying to be removed from the test sample <NUM>, other types of ion exchange resin columns <NUM> can be utilized to remove such contaminants. All interconnecting tubing, and all wetted parts can be of chemically-resistant fluoropolymer or Teflon-based material. The methods sample aspiration flow rates, wait times, and sample measurements have all been calibrated based upon the specific equipment, optical design, and measurement sensitivity.

One exemplary spectrophotometer configuration is shown in <FIG>. The spectrophotometer <NUM> can include a light source <NUM> and an entrance slit <NUM> through which the light source <NUM> passes a beam of light <NUM> towards a diffraction grating <NUM>. The diffraction grating <NUM> can refract the light <NUM> into a light prism <NUM>. The light prism <NUM> can be directed toward an exit slit <NUM>, the exit <NUM> allowing only a desired range of light wavelengths to pass through the exit slit <NUM> and through the sample <NUM> contained in a quartz cuvette <NUM>. It can be beneficial to use Quartz cuvettes <NUM> in the system <NUM> because quartz cuvettes <NUM> do not absorb UV light, which can help increase the accuracy of the test.

Absorption of light <NUM> having a wavelength between about <NUM> and <NUM> by organic compounds in the test sample <NUM> can be measured using a light detector <NUM> such as a photocell. As light <NUM> is absorbed by organic compounds in the sample <NUM>, the intensity of the light 26b exiting the sample <NUM> and the cuvette <NUM> can be less than the light 26a entering the cuvette, as shown in <FIG>. The light detector <NUM> can measure the intensity of light <NUM> exiting the sample <NUM>. The intensity of the light 26b exiting the cuvette <NUM> can be compared to the intensity of the light 26a entering the cuvette <NUM> to determine an absorption percentage or a net transmission change. A calibration curve similar to the one shown in <FIG> for an organic compound of interest can be used to determine the concentration of the organic compound of interest in the sample <NUM> based on the net transmission change percentage measured from the testing system <NUM>. While one spectrophotometer <NUM> configuration is generally shown in <FIG>, any suitable spectrophotometer <NUM> can be utilized in the system <NUM>.

In one embodiment, the Mettler Toledo UV5Bio spectrophotometer can be utilized, which can include a unique reverse optics design, which illuminates the sample with polychromatic light. The wavelength determination is done after the sample and right before the diode array or photo detector <NUM>. With this design the negative effect of ambient room light on the liquid flow path and cuvette <NUM> and thus the measurement of the sample <NUM> can be reduced. The benefit of room light immunity allows the sample <NUM> and the entire flow path to be visible to the operator, thus making any leaks or air bubbles easily detected, all of which could adversely affect the measurements' integrity and sensitivity.

The UV5Bio uses a single, pulsed-Xenon lamp as a light source, which covers the wavelength range from <NUM>-<NUM> and can be programmed to measure absorption of any wavelength or range of wavelengths between <NUM> and <NUM> nanometers. The UV5Bio can have a photometric accuracy of about ±. <NUM> amps, a wavelength accuracy of ± <NUM> nanometers, a resolution greater than <NUM>, and a stray light rating greater than <NUM>. The pulse of the flash lamp is controlled by the integrated software to ensure that the sample is only illuminated during a measurement. This can help decrease photo-bleaching effects experienced with organic molecules. The pulsed light source does not require a "warm-up" period to achieve a stable reading, which is usually required in a dual-lamp system. This allows the system <NUM> to operate faster from when the instrument is powered on until a reliable measurement can be made.

The spectrophotometer <NUM> in some embodiments can measure the entire wavelength spectrum simultaneously. By measuring the entire spectrum, rather than just a single or several wavelengths, the spectrophotometer <NUM> can allow for multiple measurements of functionality and the detection of contaminants that may occur in the sample <NUM>, and can also be used to calculate a total organic compound concentration, as opposed to a concentration of a single organic compound in the sample <NUM>.

The light detector <NUM> in some embodiments can have as many as <NUM> pixels to simultaneously measure the wavelengths required. This can allow for a significantly tighter wavelength determination compared to an array with less pixels. The dispersion element (diffraction grating) <NUM> in some embodiments can be held rigidly in place in a single mono-block. This design offers a unique field-application benefit, in that it can help eliminate any vibrational effects on the optical system that would typically be encountered. In other embodiments, the diffraction grating <NUM> can be rotatable such that the wavelength or range of wavelengths being transmitted into the sample <NUM> can be adjusted for different uses or applications.

The entire optical train of the spectrophotometer <NUM> can be set and locked in at factory settings, so that users cannot inadvertently change optical elements, which would drastically alter the results of this method. Changing optics would result in incorrect readings, without the software or operator knowing about the error.

Referring again to <FIG>, the UV5Bio system is also controlled by PC- based software with restricted user control privileges and simple shortcut menu options. The control system can also govern the timing and functioning of the pump and flow rates of the sample as discussed herein. The control system <NUM> can be in electrical communication with the pump <NUM> and the spectrophotometer <NUM> and can include a user interface <NUM> which can allow a user to control operation and timing of the system <NUM>, and can optionally allow the user to control optical setting associated with the spectrophotometer <NUM>.

The use of spectrophotometer techniques to measure the presence of organic compounds in a liquid sample <NUM> can provide significant benefits over conventional testing methods including the use of reagents or indicators which are added to the sample <NUM> and are designed to produce a color change in the sample to determine the concentration of the organic compound in the sample <NUM>. Spectrophotometry techniques can help increase the consistency, precision, and accuracy of the sample tests to reagent techniques.

One issue with spectrophotometry techniques is that contaminants in a testing sample <NUM> can negatively affect the accuracy of the tests. However, many conventional techniques utilized to remove such contaminants can adversely cause a reaction with the underlying organic compounds that could also negatively affect the accuracy of tests utilizing spectrophotometry techniques. The proprietary pretreatment techniques disclosed herein can sufficiently remove impurities and other contaminants from a liquid sample <NUM> prior to testing the sample <NUM> for the presence of desired organic compounds within the sample <NUM> with spectrophotometry techniques without removing or altering the organic compound of interest within the sample <NUM>.

Referring again to <FIG>, one aspect of a pretreatment protocol for the system <NUM> of the present disclosure is an ion exchange column <NUM>. The ion exchange column <NUM> can be designed to remove unwanted ion contaminants from a sample <NUM> prior to testing of the sample <NUM> with the spectrophotometer <NUM>. In steam boiler systems specifically, the use of a strong acid, cation-charged resin column <NUM>, or a column full or negatively charged semipermeable resin beads <NUM> as shown in <FIG>, for sample preparation can help remove common cationic contaminants that are typically known to exist in steam-water cycles. By process of common ion exchange, these cations can be converted to carbonic acid (dissolved carbon dioxide in water), which reduces the sample pH. After the strong acid cation column <NUM> processing, the sample <NUM> can then be passed through a vacuum degasser unit <NUM> as discussed in further detail herein to remove the carbon dioxide in the carbonic acid from the sample <NUM>. Sample flow is as shown in the equipment configuration layout in <FIG>. In other embodiments, the ion exchange can be an anion-charged exchange column which can remove unwanted anions from a test sample <NUM> in the event anion contaminants are common in a given application. In still other embodiments, the system <NUM> can include both a cation-charged resin column and an anion charged resin column in series to remove both cations and anions from the test sample <NUM> prior to testing with the spectrophotometer.

The strong acid cation-charged resin column <NUM> in some embodiments can utilize a clear, vertical column with color impregnated, strong acid cation-charged resin. Non-colored, commercially available resin can also be used. For application of this method, and to help ensure reliable, repeatable routine measurements, colored resin can be used. As the strong acid cation-charged resin column becomes exhausted, the resin will change color to alert the user/operator on when resin replacement or regeneration is required. Utilizing exhausted strong acid cation resin offers significant method positive interferences.

In some applications, it is beneficial to periodically regenerate the strong acid cation-charged resin column <NUM> by passing a solution of strong acid at a concentration between about <NUM> and <NUM>% through the strong acid cation-charged resin column <NUM>. In some embodiments, regeneration can occur on a daily basis to counter the effects of stagnant water left in the strong acid cation-charged resin column <NUM>, including the release of organics including polysulfates, which can contaminate the system <NUM> on startup the subsequent day. Similarly, if an anion-charged resin column is used, a solution of sodium hydroxide or another brine solution can be passed through the anion-charged resin column at similar concentrations to recharge the anion-charged resin column. In the case of a cation-charged resin column, daily passing of a strong acid solution through the entire system can provide the added benefit of helping remove any metal particles or other contaminants which may have been deposited on various components of the system, thus helping maintain the cleanliness and efficiency of the system <NUM>.

Referring again to <FIG>, a vacuum degasser unit <NUM> can be used for the sample preparation prior to testing with a spectrophotometer <NUM>. The vacuum degasser unit <NUM> can include two semipermeable tubes or vacuum degasser channels <NUM> and <NUM>. In some embodiments, the vacuum degasser channels <NUM> and <NUM> can be made from a Teflon-based material. The vacuum degasser channels <NUM> and <NUM> when exposed to a vacuum pressure <NUM> via a vacuum pump <NUM>, as shown in <FIG>, can allow for vacuum removal of certain unwanted contaminants in the sample <NUM>. For example, in some embodiments the vacuum degasser unit <NUM> can provide for vacuum-based removal of oxygen, carbon dioxide, ammonia, and low molecular weight, short-chain carboxylic acids (like formic acid, acetate, glycolate), which are contaminants typically known to exist in a user's steam water cycle. Such contaminants can negatively affect the results of the testing done with the system <NUM> as such contaminants can absorb UV light, which can potentially falsely indicate a higher concentration of a desired organic compound within the sample <NUM>. The larger long chain organic compounds that are the target of the test would not be able to pass through the semipermeable tubes of the vacuum degasser channels <NUM> and <NUM> and thus would remain in the sample <NUM>.

In some embodiments, the vacuum degasser channels <NUM> and <NUM> can be oriented parallel to one another within the vacuum degasser unit <NUM>. The size, shape, and orientation of the semipermeable tubes or channels <NUM> and <NUM> can vary in different embodiments. In still other embodiments, separate vacuum degasser devices with individual tubes or channels can be utilized in the system.

The vacuum degasser has also been shown to be especially effective at the removal of low (parts per billion) concentrations of the above contaminants, in the following order of effectiveness: carbon dioxide, oxygen, ammonia, formate, acetate, and glycolate. If not adequately removed, the above contaminants act as positive interferences for the detection method and spectrophotometer.

In some embodiments, both first and second degasser channels <NUM> and <NUM> respectively, can be contained in a single vacuum degasser unit <NUM> connected to a single vacuum pump <NUM>. In other embodiments, each vacuum degasser channel <NUM> and <NUM> can be housed in separate vacuum degasser units, each unit having its own vacuum pump <NUM>. In still other embodiments, more than two vacuum degasser channels can be utilized to further remove any unwanted contaminants from the sample <NUM>.

In some embodiments, as shown in <FIG>, the first vacuum degasser channel <NUM> can be in fluid communication between the pump <NUM> and the ion exchange column <NUM> such that the ion exchange column <NUM> is in fluid communication with the pump <NUM> via the first vacuum degasser channel <NUM>. The second vacuum degasser channel <NUM> is in fluid communication between the ion exchange column <NUM> and the spectrophotometer <NUM> such that the ion exchange column <NUM> is in fluid communication with the spectrophotometer <NUM> via the second vacuum degasser channel <NUM>. The sample <NUM> can thus be passed through a first vacuum degasser channel <NUM> to remove unwanted gases, such as carbon dioxide, from the sample prior to the sample entering the ion exchange column <NUM>. Removing such contaminants before the sample <NUM> enters the ion exchange column <NUM> can help increase the efficiency of the ion exchange process. The sample <NUM> is then passed through a second vacuum degasser channel <NUM> to remove additional carbon dioxide and other contaminants produced from the ion exchange occurring the ion exchange column <NUM>.

Referring again to <FIG>, in some embodiments, the pump can include a suction line <NUM> which can be placed in the liquid sample <NUM> to draw the liquid sample <NUM> into the system <NUM> via the pump <NUM>. In some embodiments, the liquid suction line <NUM> can include a filter media <NUM> which can be oriented such that the liquid sample passes through the filter media <NUM> as the liquid sample <NUM> is drawn into the system <NUM>. The filter media <NUM> in some embodiments can be. <NUM> micron filter such that particles larger than the filter size of the filter media <NUM> will be effectively filtered out of the sample <NUM> prior to the sample <NUM> entering the other components of the system <NUM>. Larger particles can effectively occlude or clog orifices in the semipermeable tubes of the vacuum degasser unit <NUM>, the ion exchange column, the spectrophotometer, or the fluid lines of the system <NUM> generally. Such clogging can make the vacuum degasser unit <NUM>, ion exchange column <NUM>, and spectrophotometer <NUM> less efficient, and can potentially cause back-pressure in the system <NUM> which is undesirable.

In some embodiments, the filter media <NUM> can be made of a chemically resistant material such that as the sample <NUM> passes through the filter media <NUM> deposits of contaminants from the filter media <NUM> into the sample <NUM> can be minimized. In some embodiments, the filter media <NUM> can be made from a chemically resistant thermoplastic including but not limited to polyether ether ketone (PEEK), or any other suitable polyarytherketone (PAEK). In some embodiments, the filter media <NUM> once consumed can simply be replaced. However, having a chemically resistant filter media <NUM> can allow an acid wash to pass through the filter media <NUM> to clean the filter media <NUM> of any collected contaminants while not damaging the filter media <NUM> or introducing reacted contaminants from the filter media <NUM> into the system <NUM>.

The filter media <NUM> is shown in <FIG> on the suction line <NUM> of the pump <NUM>. In some embodiments, one or more filter media <NUM> can be placed in various places within the system <NUM> to help maximize filtering of larger particles from the sample <NUM>. However, having the filter media <NUM> generally at the beginning of the flow path of the system <NUM> can help prevent large particles from contaminating or clogging various pieces of equipment within the system as previously discussed. It can also be beneficial to periodically (semiannually or annually) disconnect the ion exchange column and run a strong acid wash having a concentration of roughly <NUM> percent strong acid through remaining components of the system <NUM> to remove any unwanted contaminants that may be deposited in various components of the system <NUM>, and then thoroughly rinse all components of the system with fresh water thereafter.

Samples collected from a liquid source such as a power plant or other boiler steam-generating locations can ideally be collected after any water sampling/conditioning panel of the liquid source/steam boiler system. Since this method and equipment configuration utilizes one or more ion exchange columns, including but not limited to a strong acid cation column (included in the sample flow path), water samples collected before a cation column sampling panel of a liquid source/steam boiler system can also be analyzed, although not preferred.

Water samples received from users for analysis can ideally have no sample preservation. No acids can be added to the sample and care should be taken to not subject the sample to freezing temperatures before or during transport, or prior to analysis. Such preservatives, acids, and/or temperature disparities can affect the integrity and sensitivity of the testing method.

Samples should be collected and analyzed as soon as possible and ideally within a few days of sample collection. Water samples should ideally be collected in new, clean, and rinsed <NUM> HDPE sample bottles. Sample degradation/bottle contamination contributes a false positive error rate of approximately <NUM> parts per billion per day after initial sample collection.

The sample, once received and prior to analysis, can be brought to typical ambient temperatures (<NUM> to <NUM>), accomplished by either external sample warming or cooling, using typical laboratory-based devices such as a temperature bath. In some embodiments, the sample <NUM> can be placed in a temperature bath of between about <NUM> to <NUM>, to bring the temperature of the sample to between about <NUM> to <NUM>. In still other embodiments, the sample <NUM> can be placed in a temperature bath of about <NUM>, to bring the temperature of the sample to between about <NUM>. Bringing the sample <NUM> to a consistent temperature can help produce consistent results and test between samples being collected from different locations where temperatures may vary. Once the sample <NUM> reaches the desired temperature, testing should be done relatively quickly, such as within <NUM> minutes, to help ensure the sample <NUM> is tested at as close to the desired temperature as possible.

The flow path through the system <NUM> and sample <NUM> aspiration is accomplished by pumping of the sample, for instance using a FillPalMini peristaltic pump. The water sample <NUM> to be tested is aspirated by the FillPalMini, passed through the first vacuum degasser channel <NUM> of the vacuum degasser unit <NUM>, and then routed through the ion exchange column <NUM>, or strong acid cation-charged resin column <NUM>. The discharge from the ion exchange column <NUM> is then passed through the second vacuum degassing channel <NUM>, the discharge of which is then passed through the spectrophotometer <NUM>, and specifically through a flow-through quartz cuvette <NUM>, and then finally, to a drain or waste collection site <NUM>. The quartz cuvette <NUM> in some embodiments can be a <NUM> quartz cuvette <NUM>, though cuvettes <NUM> of varying sizes can be utilized.

The start of the method involves aspirating a pure water sample <NUM> from the water sample <NUM> collection container using a suitable pump <NUM>, such as a peristaltic pump, at a flow rate of between about <NUM>-<NUM>/min for a duration of <NUM> seconds. In some embodiments, the flowrate of this initial flow stage can be about <NUM>/min. During these <NUM> seconds, the sample <NUM> enters the first vacuum degasser channel <NUM>. The sample <NUM> then flows through the ion exchange column <NUM>, through to the second vacuum degasser channel <NUM>, through the quartz cuvette <NUM>, and finally to drain. This procedure helps remove bulk volatile contaminants and to flush the entire liquid flow path of a previous sample prior to the current sample being tested.

Software program settings on the control unit <NUM> can then be programmed to change the aspiration and/or pumping rate of the sample <NUM>, decreasing it from <NUM>-<NUM> per minute down to between about <NUM>-<NUM> per minute, for an additional duration of <NUM> seconds. In some embodiments, the flow rate of this second stage of the testing procedure can be about <NUM>/min. The sample <NUM> flow path remains the same as discussed above.

After completing the <NUM>-second sample <NUM> aspiration, the system <NUM> can enter a forced sample stand/wait period, for instance a <NUM>-<NUM> second wait period, followed by an immediate initiation of the spectrophotometer's high-powered Xenon light source. The sample <NUM> can be impacted for a <NUM>-second period with a desired wavelength of light, which in some circumstances can be a full wavelength range of light. The spectrophotometer <NUM> can take multiple readings and offers a calculated average result. The spectrophotometer <NUM> can only activate the light source <NUM> when required and remains on standby when not being used, which extends the lifespan of this core part of the spectrophotometer <NUM>.

A minimum sample volume of <NUM> can be required depending on the size of the cuvette <NUM> and the established flow rates of the system <NUM> during the testing. An ideal working solution volume (to allow for repeat sample analysis and/or errors) would be between <NUM> and <NUM>.

All program options, method procedures, timers, method prompts, flowrates, and calibration slope information are all pre-programmed on the spectrophotometer <NUM>.

Water samples to be analyzed using this method should ideally be collected after the user's sample conditioning panel cation columns. However, if not available, this method can still be applied to samples collected before the user's cation column sample conditioning panel, as the instrument comes equipped with a strong-acid cation exchange column.

Typical high-pressure power plant, steam-water cycle contaminants were evaluated, namely: phosphates, hydrazine, carbohydrazide, sodium hydroxide, ammonia, ammonium carbamate, formate, acetate and glycolate. The dissociation of these contaminants in the high-temperature cycle, as either cationic or anionic contaminants, is noted.

Since a strong-acid cation exchanger column is utilized, either on the user's sample conditioning panel or in the included equipment configuration, many of the contaminants would merely be exchanged and converted to carbon dioxide (carbonic acid), which would ultimately be liberated by the second vacuum degasser channel <NUM>.

Carboxylic acids, however, would not be removed by the cation column, but are still, in major part, liberated by effective vacuum degassing. These interferences were analyzed for their contribution under typical cycle chemistry conditions, listed below:.

Claim 1:
A method of testing a water sample (<NUM>) for at least one anti-corrosion saturated and/or unsaturated aliphatic nitrogen containing organic compound, the method comprising the steps of:
collecting the water sample (<NUM>) from a thermal power system or other steam water cycle;
passing the water sample (<NUM>) through an ion exchange column (<NUM>);
passing the water sample (<NUM>) through a first vacuum degassing channel (<NUM>) after passing through the ion exchange column (<NUM>);
transmitting light (<NUM>) having a wavelength of between <NUM> and <NUM> into the water sample (<NUM>) after the water sample (<NUM>) has passed through the first vacuum degassing channel (<NUM>);
measuring absorption/transmission of the light (<NUM>) having a wavelength of between <NUM> and <NUM> by the at least one saturated and/or unsaturated aliphatic nitrogen containing organic compound in the water sample (<NUM>);
determining a concentration of the at least one saturated and/or unsaturated aliphatic nitrogen containing organic compound within the water sample (<NUM>) based on the absorption/transmission of the light (<NUM>) having a wavelength of between <NUM> and <NUM> by the at least one saturated and/or unsaturated aliphatic nitrogen containing organic compound.