JP2009257773A - Device and method for measuring hydrophilic nonionic material content - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring method of a hydrophilic nonionic material content capable of measuring the content of a hydrophilic nonionic material in water highly accurately in a short time in online measurement, especially even in the case of repeated measurement. <P>SOLUTION: This measuring method of the hydrophilic nonionic material content has processes for: supplying mixed liquid including sample water containing the hydrophilic nonionic material and pure water to an ion exchanger 31; determining the hydrophilic nonionic material by a mass spectrometer 40 by using outflow liquid flowing out from the ion exchanger 31 as a measuring sample; and supplying the mixed liquid to the ion exchanger 31, and then supplying desorption liquid for desorbing ions adsorbed onto the ion exchanger to the ion exchanger 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a measuring apparatus and a measuring method for measuring the content of a hydrophilic nonionic substance such as urea in water.

Water may contain hydrophilic nonionic substances such as urea, and depending on the use of water, monitoring of the content may be required. A colorimetric analysis method is known as a method for measuring the urea content in water (see Non-Patent Document 1).
Edited by the Japanese Pharmaceutical Society, “Hygiene Testing Methods / Comments 2000”, Kanehara Publishing, 2000, p. 810-811

However, the colorimetric analysis method has a problem that if the measurement sample contains a protein, a positive error occurs and the accuracy is lowered. Moreover, the lower limit of quantification was about 100 μg / L, and measurement at a lower concentration was difficult.
Moreover, since hydrophilic nonionic substances, such as urea, have high affinity with water, it is difficult to completely separate from water, and there is no adsorbent that can selectively adsorb hydrophilic nonionic substances. Therefore, it could not be concentrated easily. Therefore, in the colorimetric analysis, when the aqueous solution containing the hydrophilic nonionic substance is concentrated, the concentration time becomes long, and as a result, the entire process including the concentration process takes 10 hours or more.
In addition, water quality monitoring is required to be able to be measured online, but online automatic measurement by flow injection colorimetric analysis has only been put into practical use.

By the way, a method using a mass spectrometer is known as a measuring method with high accuracy and on-line measurement. However, when ions are present in the hydrophilic nonionic substance, the content of the hydrophilic nonionic substance cannot be accurately determined even by a mass spectrometer.
Therefore, it is conceivable that ions are adsorbed and captured in advance by an ion exchanger before measurement with a mass spectrometer. However, repeated measurement tends to lower the measurement accuracy.
The present invention has been made in view of the above circumstances, and can be measured online. In particular, even in the case of repeated measurement, the content of hydrophilic nonionic substances in water is measured in a short time and with high accuracy. An object of the present invention is to provide an apparatus and a method for measuring the content of hydrophilic nonionic substances that can be produced.

The present invention includes the following aspects.
[1] A pure water supply unit for supplying pure water;
A sample water mixing unit that obtains a mixed solution by mixing sample water containing a hydrophilic nonionic substance into the pure water supplied from the pure water supply unit;
An ion exchanger through which the mixture is passed;
A mass spectrometer for quantifying hydrophilic nonionic substances using the effluent flowing out of the ion exchanger as a measurement sample;
An apparatus for measuring the content of hydrophilic nonionic substances, comprising: a desorption liquid supply unit that supplies a desorption liquid for desorbing ions adsorbed to the ion exchanger to the ion exchanger.
[2] The hydrophilic nonionic substance content measuring device according to [1], wherein the ion exchanger is a cation exchanger.
[3] The hydrophilic nonionic substance content measuring device according to [1], wherein the ion exchanger is an anion exchanger.
[4] The hydrophilic nonionic substance content measuring device according to [2], wherein the hydrophilic nonionic substance is urea.
[5] supplying a mixed liquid containing sample water and pure water containing a hydrophilic nonionic substance to the ion exchanger;
Using the effluent flowing out of the ion exchanger as a measurement sample, quantifying a hydrophilic nonionic substance with a mass spectrometer,
A method for measuring the content of a hydrophilic nonionic substance, comprising: supplying a desorption liquid for desorbing ions adsorbed to the ion exchanger after the mixed liquid is supplied to the ion exchanger. .
[6] The method for measuring a hydrophilic nonionic substance content according to [5], wherein a cation exchanger is used as the ion exchanger.
[7] The method for measuring a hydrophilic nonionic substance content according to [5], wherein an anion exchanger is used as the ion exchanger.
[8] The method for measuring the content of a hydrophilic nonionic substance according to [6], wherein the hydrophilic nonionic substance is urea.

  According to the measurement apparatus and measurement method for the content of hydrophilic nonionic substances of the present invention, on-line measurement is possible, especially even in the case of repeated measurement, hydrophilic nonionic substances in water in a short time and with high accuracy. The content of can be measured.

<Measurement device for hydrophilic nonionic substance content>
An embodiment of the measurement device for the content of hydrophilic nonionic substances of the present invention will be described.
FIG. 1 shows a measurement device (hereinafter abbreviated as a measurement device) of hydrophilic nonionic substance content of the present embodiment. This measuring device 1 is a device that measures the content of a hydrophilic nonionic substance contained in sample water.
Examples of the hydrophilic nonionic substance to be measured in the measuring apparatus 1 include nitrogen-containing compounds such as urea, lower alcohols such as methanol and ethanol, ketones such as acetone, and ethers such as dimethyl ether. .

The measuring apparatus 1 according to the present embodiment includes a pure water supply unit 10 that supplies pure water, and sample water containing a hydrophilic nonionic substance is mixed with pure water supplied from the pure water supply unit 10. A sample water mixing unit 20 for obtaining a mixed liquid, a liquid chromatograph 30 having an ion exchanger 31 through which the mixed liquid is passed as a column, and a non-ionic substance that is hydrophilic using an effluent discharged from the liquid chromatograph 30 as a measurement sample. A mass spectrometer 40 for quantification, a desorption liquid supply unit 50 for supplying a desorption liquid to the liquid chromatograph 30, and a downstream side of the liquid chromatograph 30 and an upstream side of the mass spectrometer 40, and a flow path for the effluent. And a flow path switching valve 60 for switching.
The measuring apparatus 1 also includes a first pipe 71 and a second pipe 72 that connect the pure water supply unit 10 to the sample water mixing unit 20, and a third pipe that connects the sample water mixing unit 20 to the liquid chromatograph 30. A pipe 73, a fourth pipe 74 that connects the liquid chromatograph 30 to the flow path switching valve 60, a fifth pipe 75 that connects the flow path switching valve 60 to the mass spectrometer 40, and the desorption liquid supply unit 50 A sixth pipe 76 connected to the second pipe 72 and a seventh pipe 77 connected to the flow path switching valve 60 for discharging the effluent from the measuring device 1 are provided.

  The pure water supply unit 10 constituting the measuring device 1 includes a pure water tank 11 filled with pure water, and a pure water supply pump 12 for supplying pure water from the pure water tank 11 to the sample water mixing unit 20. It comprises. In such a pure water supply unit 10, the pure water in the pure water tank 11 can be supplied to the sample water mixing unit 20 by the pure water supply pump 12.

The sample water mixing unit 20 has means for injecting sample water into the pure water supplied by the pure water supply unit 10. The injection may be automatic or manual.
The sample water mixing unit 20 is connected to a facility that handles water, and can inject sample water collected from the facility that handles water.

As the liquid chromatograph 30, a known high-speed liquid chromatograph can be used.
The ion exchanger 31 provided in the liquid chromatograph 30 is appropriately selected according to the ionization method of the hydrophilic nonionic substance in the mass spectrometer 40. That is, in the mass spectrometer 40, when the hydrophilic nonionic substance is ionized to become positive ions, the measurement accuracy decreases when cations coexist in the sample water. Is used. Examples of the cation exchanger include a resin having an acid group such as a sulfonic acid group or a carboxyl group.
On the other hand, when the hydrophilic nonionic substance is ionized into negative ions in the mass spectrometer 40, the anion exchanger 31 serves as the ion exchanger 31 because the measurement accuracy decreases when anions coexist in the sample water. Is used. Examples of the anion exchanger include a resin having a quaternary ammonium group.
Moreover, as an ion exchanger, an ion exchange resin, a silica gel ion exchanger, a monolithic organic porous ion exchanger, etc. can be used, for example.

The mass spectrometer 40 is not particularly limited. For example, the ionization method for performing mass spectrometry may be any one of an atmospheric pressure chemical ionization method, a fast electron impact method, an electrospray ionization method, and the like.
The analysis unit may be any of a magnetic field deflection type, a quadrupole type, an ion trap type, a time-of-flight type, and a Fourier transform ion cyclotron resonance type.

The desorption liquid supply unit 50 includes a desorption liquid tank 51 filled with the desorption liquid, and a desorption liquid supply pump 52 for supplying pure water from the desorption liquid tank 51 to the sample water mixing unit 20. In such a desorption liquid supply unit 50, the desorption liquid in the desorption liquid tank 51 can be supplied to the sample water mixing unit 20 by the desorption liquid supply pump 52.
Here, the desorption liquid is a liquid that causes ions adsorbed on the ion exchanger 31 to be desorbed from the ion exchanger 31 and eluted. When the ion exchanger is a cation exchanger, an aqueous solution of an organic acid such as formic acid or acetic acid, a mineral acid such as hydrochloric acid or sulfuric acid, or the like can be used. Among these, formic acid and acetic acid are more preferable because corrosion of the measuring device can be suppressed.
Moreover, as a desorption liquid in case an ion exchanger is an anion exchanger, alkaline aqueous solutions, such as sodium hydroxide, potassium hydroxide, ammonium salt, etc. can be used, for example.

  The flow path switching valve 60 is for switching the flow path of the effluent that has passed through the fourth pipe 74 to one of the fifth pipe 75 and the seventh pipe 77. Note that when the effluent is passed through the seventh pipe 77, the effluent is discharged from the measuring device 1.

<Measurement method of hydrophilic nonionic substance content>
Next, a method for measuring the content of the hydrophilic nonionic substance using the measuring device 1 (hereinafter abbreviated as a measuring method) will be described.
In the measurement method according to this embodiment, first, pure water is supplied from the pure water tank 11 of the pure water supply unit 10 by the pure water supply pump 12 through the first pipe 71 and the second pipe 72. Supply to the mixing unit 20.
The pure water supplied at this time serves as a carrier for feeding sample water into the mass spectrometer 40. In addition, as pure water, it is preferable to use pure water that does not contain a hydrophilic nonionic substance in terms of improving measurement accuracy.

Next, in the sample water mixing unit 20, sample water is poured into pure water and mixed to obtain a mixed solution.
Next, the mixed solution is supplied to the liquid chromatograph 30 through the third pipe 73 and passed through the ion exchanger 31. At this time, ions contained in the mixed solution are adsorbed by the ion exchanger 31 and captured.

  Subsequently, the flow path of the effluent that has flowed out from the ion exchanger 31 of the liquid chromatograph 30 is switched in advance so that the fourth pipe 74 and the fifth pipe 75 communicate with each other via the fourth pipe 74. Supplied to the flow path switching valve 60 and supplied to the mass spectrometer 40 via the fifth pipe 75. Then, in the mass spectrometer 40, the hydrophilic nonionic substance is quantified using the mixed solution as a measurement sample.

Thereafter, the supply of pure water from the pure water supply unit 10 is stopped, and the flow path of the flow path switching valve 60 is switched so that the fourth pipe 74 and the seventh pipe 77 communicate with each other.
Next, the desorption liquid is supplied from the desorption liquid tank 51 of the desorption liquid supply unit 50 by the desorption liquid supply pump 52 through the sixth pipe 76, the second pipe 72, the sample water mixing unit 20, and the third pipe 73. To the liquid chromatograph 30. Thereby, the desorption liquid is passed through the ion exchanger 31, and the ions adsorbed on the ion exchanger 31 are desorbed and regenerated. The desorption liquid containing ions is discharged from the measuring device 1 through the fourth pipe 74, the flow path switching valve 60, and the seventh pipe 77.

Next, the supply of the desorption liquid from the desorption liquid supply unit 50 is stopped, and the flow path of the flow path switching valve 60 is switched so that the fourth pipe 74 and the fifth pipe 75 communicate with each other.
By repeating the above series of steps at a predetermined interval, the content of hydrophilic nonionic substance can be measured at a predetermined interval.

In the measurement apparatus 1 and the measurement method described above, ions contained in the sample water together with the hydrophilic nonionic substance can be captured by the ion exchanger 31 of the liquid chromatograph 30, so that the mass spectrometer 40 does not coexist with ions. The content of hydrophilic nonionic substances can be measured on the sample. Moreover, since the desorption liquid is supplied to the ion exchanger 31 by the desorption liquid supply unit 50 after passing the mixed liquid through the ion exchanger 31, the ions adsorbed on the ion exchanger 31 can be desorbed. As a result, in the case of repeated measurement, the mixed solution can be passed through the regenerated ion exchanger 31, so that ions can be sufficiently captured and a reduction in measurement accuracy can be prevented. From these things, according to the said measuring apparatus 1 and the measuring method, even if it measures repeatedly, content of a hydrophilic nonionic substance can be measured with high precision.
Moreover, in the said measuring apparatus 1 and a measuring method, since there is no sample water concentration operation, it can measure in a short time.
Furthermore, in the measurement apparatus 1 and the measurement method, measurement can be performed online by connecting water handling equipment to the sample water mixing unit 20.

Note that the present invention is not limited to the above embodiment.
For example, in the embodiment described above, the flow path switching valve 60 is provided and the flow path of the effluent is switched. However, all of the effluent is sent to the mass spectrometer 40 without the flow path switching valve 60. It doesn't matter.
In the above embodiment, the ion exchanger 31 is provided in the liquid chromatograph 30, but it may be a single one that is not provided in the liquid chromatograph 30. For example, a solid phase extraction column, a column packed with an ion exchange resin, or the like may be used.

The above-described measuring apparatus and measuring method are used to monitor a small amount of hydrophilic nonionic substances in water equipment used in the production of electronic components such as semiconductors and liquid crystals, tap water purification plants, medical water production equipment, and power plants. Can be suitably used.
It can also be used for monitoring the amount of decomposition in an apparatus for decomposing hydrophilic nonionic substances in water.

Using the measurement apparatus 1, the urea content of the sample water shown in Table 1 was measured as follows.
First, pure water is supplied from the pure water tank 11 of the pure water supply unit 10 to the autosampler which is the sample water mixing unit 20 via the first pipe 71 and the second pipe 72 by the pure water supply pump 12. Feeded at 0.2 mL / min.
Next, sample water was injected into pure water at the sample water mixing unit 20 to prepare a mixed solution. Next, the mixed solution is supplied to the liquid chromatograph 30 (Agilent Technologies Agilent 1100) via the third pipe 73, and the ion exchanger 31 (cation exchange resin, Tosoh Corporation IC-Cation, inner diameter). 4.6 mm × length 50 mm).
Subsequently, the flow path of the effluent that has flowed out from the ion exchanger 31 of the liquid chromatograph 30 is switched in advance so that the fourth pipe 74 and the fifth pipe 75 communicate with each other via the fourth pipe 74. The flow path switching valve 60 was supplied. Furthermore, it was supplied to the mass spectrometer 40 (API 3200QTRAP LC / MS / MS system manufactured by Applied Biosystems) via the fifth pipe 75 to quantify urea. The measurement results are shown in Table 1.

Ten minutes after the start of the supply of pure water, the supply of pure water from the pure water supply unit 10 is stopped and the flow path of the flow path switching valve 60 is communicated with the fourth pipe 74 and the seventh pipe 77. Switched to
Next, a 0.1 mass% formic acid aqueous solution as a desorption liquid is supplied to the liquid chromatograph 30 from the desorption liquid tank 51 of the desorption liquid supply unit 50 by the desorption liquid supply pump 52, and passes through the desorption liquid to the ion exchanger 31. I let you. The desorption liquid containing ions was discharged from the measurement apparatus 1 through the seventh pipe 77.
Next, 15 minutes after the start of the supply of pure water, the supply of the desorption liquid from the desorption liquid supply unit 50 is stopped, and the flow path of the flow path switching valve 60 is connected to the fourth pipe 74 and the fifth pipe 75. Switched to communicate. Then, pure water was again supplied from the pure water tank 11 of the pure water supply unit 10 to the auto sampler as the sample water mixing unit 20 by the pure water supply pump 12.
After 20 minutes from the start of supplying the first pure water, it was confirmed that the liquid flowing through the sample water mixing unit 20 was replaced with pure water from the desorption liquid. Therefore, the measurement time in this measuring apparatus 1 was 20 minutes.

  In the above measurement method, since the ion exchanger is regenerated by formic acid, the same measurement accuracy as the first time can be maintained in the second and subsequent measurements.

It is a figure which shows typically the measuring apparatus of hydrophilic nonionic substance content of this invention.

Explanation of symbols

1 Measuring device (Measuring device for hydrophilic nonionic substance content)
DESCRIPTION OF SYMBOLS 10 Pure water supply part 11 Pure water tank 12 Pure water supply pump 20 Sample water mixing part 30 Liquid chromatograph 31 Ion exchanger 40 Mass spectrometer 50 Desorption liquid supply part 51 Desorption liquid tank 52 Desorption liquid supply pump 60 Flow path Switch valve 71 1st piping 72 2nd piping 73 3rd piping 74 4th piping 75 5th piping 76 6th piping 77 7th piping

Claims (8)

A pure water supply section for supplying pure water;
A sample water mixing unit that obtains a mixed solution by mixing sample water containing a hydrophilic nonionic substance into the pure water supplied from the pure water supply unit;
An ion exchanger through which the mixture is passed;
A mass spectrometer for quantifying hydrophilic nonionic substances using the effluent flowing out of the ion exchanger as a measurement sample;
An apparatus for measuring the content of hydrophilic nonionic substances, comprising: a desorption liquid supply unit that supplies a desorption liquid for desorbing ions adsorbed to the ion exchanger to the ion exchanger.   2. The hydrophilic nonionic substance content measuring apparatus according to claim 1, wherein the ion exchanger is a cation exchanger.   2. The hydrophilic nonionic substance content measuring apparatus according to claim 1, wherein the ion exchanger is an anion exchanger.   The hydrophilic nonionic substance content measuring device according to claim 2, wherein the hydrophilic nonionic substance is urea. Supplying a mixed liquid containing sample water and pure water containing a hydrophilic nonionic substance to the ion exchanger;
Using the effluent flowing out of the ion exchanger as a measurement sample, quantifying a hydrophilic nonionic substance with a mass spectrometer,
A method for measuring the content of a hydrophilic nonionic substance, comprising: supplying a desorption liquid for desorbing ions adsorbed to the ion exchanger after the mixed liquid is supplied to the ion exchanger. .   6. The method for measuring a hydrophilic nonionic substance content according to claim 5, wherein a cation exchanger is used as the ion exchanger.   6. The method for measuring a hydrophilic nonionic substance content according to claim 5, wherein an anion exchanger is used as the ion exchanger.   The method for measuring the content of a hydrophilic nonionic substance according to claim 6, wherein the hydrophilic nonionic substance is urea.

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