JPH0820428B2 - Anion analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention introduces a concentrated solution to be measured to a separation column by an eluent to separate anions in the solution to be measured into a chromatographic column and elutes from the separation column. More specifically, the present invention relates to an anion analyzer for analyzing anions, in which a concentrated solution to be measured is sequentially delivered to a separation column by an eluent from a switching valve having a concentration column in which concentration is completed,
The present invention relates to an anion analyzer capable of continuously measuring a plurality of liquids having extremely low concentrations with high accuracy in a short time.

<Prior Art> As is well known, ion chromatography is an analytical method that chromatographically separates and analyzes various ions in a liquid to be measured. A liquid is used as a mobile phase to chromatographically measure an object to be measured in the liquid to be measured. It is one of so-called liquid chromatography for separating and analyzing. When a concentration column is used in such ion chromatography, it is possible to accurately measure a low concentration (ppb or sub ppb level) of anions present in the liquid to be measured. That is, a certain amount of the solution to be measured is passed through a concentration column, low-concentration anions in the solution to be measured are concentrated and retained, and then the eluent, which is a mobile phase, is conveyed to the separation column. To separate the anion of Chromatographically into a detector, and then to detect the conductivity, for example, to measure the low-concentration anion in the liquid to be measured from the chromatogram created based on the detection signal. It was.

However, in the above-mentioned conventional example, if an extremely low concentration (ppt level) of anions present in the liquid to be measured is to be accurately measured, the time for concentrating the anions becomes long and, as a result, the total analysis time becomes longer. It had the drawback of being long.
That is, a solution to be measured containing anions of several ppt level (for example, 2 to 5 ppt Nl ⁻ ion, Br ⁻ ion, SO ₄ ²⁻ ion, etc.) is applied to the above-mentioned concentration column for 10 minutes at a flow rate of 2 ml / min. When it is supplied to the column, 2 (ml / min.) X 10 (min.) = 20 (ml) of the solution to be measured will pass through the concentration column, resulting in 0.2-0.5ppt.
In order to measure the anions (eg Cl ^- ion, Br ^- ion, SO ₄ ^2- ion, etc.), it is necessary to supply the liquid to be measured to the above concentration column for 100 minutes at a flow rate of 2 ml / min. It was On the other hand, it takes about 10 minutes to guide the ions concentrated in the concentration column to the separation column, chromatographically separate them, and detect them by the detector. Therefore, if an extremely low concentration (ppt level) of anions present in the liquid to be measured is to be measured accurately, the time for concentrating the anions is much higher than that for the separation column. However, there is a drawback that the analysis time becomes long and the total analysis time becomes long.

<Problems to be Solved by the Invention> The present invention has been made in view of the drawbacks of the conventional example, and an object thereof is to quickly and accurately analyze anions in a liquid to be measured using ion chromatography. An object of the present invention is to provide an anion analyzer that can be used.

<Means for Solving Problems> In order to achieve such an object, the present invention introduces a concentrated liquid to be measured to a separation column by a melt to chromatograph anions in the liquid to be measured. In an anion analyzer for separating and analyzing anions eluted from the separation column, the anion analyzer is connected in series to a flow path for supplying the eluent to the separation column, and concentrates a liquid to be measured in each of the channels. A plurality of switching valves are provided which have a concentration column and switch the flow of the measured liquid to the concentration column by switching the valve and also switch the measured liquid concentrated in the concentration column to the flow channel on the separation column side. It is characterized in that the concentrated liquid to be measured is sequentially sent out to the separation column by the eluent from a switching valve having a concentration column which is provided and has completed concentration.

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration explanatory view of an ion analyzer for explaining an embodiment of the present invention, and FIG. 2 is a time chart explaining an operation of the embodiment of the present invention. In FIG. 1, 1A, for example eluent tank eluant consisting of a solution of _{4mM · Na 2 CO 3 / 4mM} · NaHCO 3 is formed by the reservoir, 1B, for example removal solution comprising at 15mM solution of H ₂ SO ₄ reservoir The removal liquid tanks 1C _{1 to} 1C _n are, for example, first to nth sample tanks in which first to nth samples containing anions of several ppt in different concentrations and compositions are stored. , 2A, 2B, and 2C _{1 to} 2C _n are liquid feed pumps, 3A is a manual sample injection valve whose internal flow path is alternately switched between a solid line connection state and a broken line connection state, and 3C _{1 to} 3C _n are internal flow channels with a solid line First to n-th sample switching valves which are alternately switched between the connected state and the broken line connected state,
4B is, for example, a measuring tube having an inner volume of 0.1 ml, 4C _{1 to} 4C _n are, for example, first to nth concentration columns filled with anion exchange resin, and 5 are, for example, anion exchange resin (in the concentration column). Column is filled with an anion exchange resin having an ion exchange capacity of 1/3 to 1/2 that of the anion exchange resin filled in 6), 6 is, for example, a cation exchange membrane 6a A suppressor partitioned between 6b and the outer chamber 6c, 7 is a detector such as a conductivity meter, 8 is a separation column 5, sublesser
It is a thermostatic chamber that houses 6 and the detector 7 and maintains a constant temperature (for example, 45 ° C.). Incidentally, the manual sample injection valve 3B has its internal channel when the off a solid line connected state, the first to the sample switching valve 3C ₁ ~3C _n its internal passage solid connection state when on the first n Is configured to be.

In the ion analyzer having the configuration as shown in FIG. 1, first, the manual sample injection valve 3B and the first to nth switching valves are provided.
3C ₁ ~3C _n is turned off. When the liquid feed pump 2A is driven in this state, the liquid feed pump 2A → the first and sixth connection of the first sample switching valve 3C ₁ at a flow rate of the eluent in the eluent tank 1A is, for example, 2 ml / min. Port a, f → Concentration column 4C ₁ → 1st sample switching valve 3C ₁
3rd and 2nd connection ports c and b of → the 1st of 2nd sample switching valve 3C ₂
And the sixth connection port a, f → concentration column 4C ₂ → second sample switching valve
The third and second connecting port c of 3C _2, b → ............ → first and sixth connecting port a of the n sample switching valve 3C _n, f → concentration column 4C _n →
Third and second connection ports c, b of _n- th sample switching valve 3C _n → first and second connection ports a, b of manual sample injection valve 3B → separation column 5
→ The inner chamber 6b of the suppressor 6 → Flows to a waste liquid tank (not shown) via the detector 7. Further, when the liquid feed pump 2B is driven, the removal liquid in the cleaning liquid tank 1c flows through the liquid feed pump 2B → outer chamber 6c of the suppressor 6 to a waste liquid tank (not shown). Therefore, in the suppressor 6, the cations in the removing liquid flowing in the inner chamber 6b and the cations in the liquid flowing in the inner chamber 6b are ion-exchanged through the cation exchange membrane 6a and the liquid flowing in the inner chamber 6b. The conductivity background is removed. Furthermore, when the liquid feed pumps 2C _{1 to} 2C _n are driven, the sample tanks 1C _{1 to} 1C _n
The liquid to be measured (for example, the liquid to be measured containing anions of several ppt) is a liquid feed pump 2C _{1 to} 2C _n → the first to nth sample switching valves
It flows to the respective waste liquid tanks (not shown) via the fourth and fifth connection ports d and e respectively provided in 3C _{1 to} 3C _n .
In this state, as shown in FIG. 2, the first sample switching valve 3C ₁ is _first turned on (that is, at time 0 minutes), and then at time 1
At 0 minute, the second sample switching valve 3C ₂ is turned on, and then the third to nth sample switching valves 3C _{3 to} 3C _n are sequentially turned on every 10 minutes. Incidentally, the sample switching valve 3C ₁ ~3C _n of the first to n are turned on, the measured liquid sample tanks 1C within ₁ ～1C _n is liquid supply pump 2C ₁ ~2C _n → first to 4th and 3rd connection ports d, c provided in the sample switching valves 3C _{1 to} 3C _n of _n → 1st to nth concentration columns 4C _{1 to} 4C _n → 1st to nth sample switching valves 3C ₁ ~ 3
6th and 5th connection ports f and e respectively provided in C _n
Through each of the waste liquid tanks (not shown). Therefore, the concentration column 4C ₁ ~4C _n of the first to n test solution is supplied to the sample switching valve 3C ₁ ~3C _n of the first to n are turned off,該被measurement liquid within Of the anions are captured and concentrated in the _first to nth concentration columns 4C _{1 to} 4C _n .

In the above-described state, as shown in FIG. 2, the first sample switching valve 3C ₁ is turned off 100 minutes after being turned on. At this time, if the flow rate of the liquid feed pump 2C ₁ is 2 ml / min., The measured liquid in the sample tank 1C ₁ is 2 (ml / min.) × 100 (min.) = 2
Only 00 (ml) passes through the first concentration column 4C ₁ and the anions in the solution to be measured are captured and concentrated by the first concentration column 4C ₁ .
After that, when the first sample switching valve 3C ₁ is turned off, the anions captured and concentrated in the first concentration column 4C ₁ are transferred to the eluent, and the first sample switching valve 3C ₂ 's first and Sixth connection port a, f → ......... First and second connection port a, b of _n- th sample switching valve 3C _n → First and second connection port of manual sample injection valve 3B
It passes through a and b, reaches the separation column 5, and is chromatographically separated. The eluate of the separation column 5 is a detector 6
Then, the conductivity is detected, and a chromatogram is drawn on a recorder (not shown) or the like based on the detected signal. From this chromatogram, it can be confirmed that all monovalent anions (Cl ⁻ ion, Br ⁻ ion, SO ₄ ²⁻ ion, etc.) are eluted within 10 minutes.

After the first sample switch valve 3C ₁ is turned off, the every 10 minutes 2
Samples switching valve 3C ₂ ~3C _n th to n are one after another off.
It should be noted that the numbers 1 to 11 in the sample number (c) of FIG. 2 indicate the sample numbers of the above-mentioned chromatograms, and the chromatograms due to the anions eluting from the separation column 5 in the corresponding time zone (10 minutes). Indicates which sample is the chromatogram. In this manner, the monovalent anions contained in the liquid to be measured in the _first to n-th sample tanks 1C _{1 to} 1C _n are successively captured and concentrated in the respective concentration columns to obtain the monovalent anions. It becomes possible to measure chromatographically.

In addition, since the first sample switching valve 3C ₁ is first turned on,
After 10 minutes, i.e. the first sample switch valve 3C ₁ is turned on again from the 11 sample switching valve 3C ₆ is turned off after 10 minutes. By doing so, it is possible to measure one dianion contained in the test liquid of the first to the sample vessel 1C ₁ ～1C _n of the n by respectively twice. The time chart of FIG. 2 shows a case of measuring a dianion that is contained in the measurement liquid in the sample vessel 1C ₁ ～1C ₁₁ of the first to 11 by each twice. Further, to stop the measurement, a sample selector valve 3C ₁ ~3C _n of the first to n may be cease on again later, which is turned off.

Further, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the following modifications (a) and (b) may be applied.

(B) without using the sample vessel 1C ₁ ~1C _n of first through n, to continuously measure a dianion that is included in the line connected to process samples.

(B) Even if the solution to be measured having the same composition is supplied to the inlet side of the liquid feed pumps 2C _{1 to} 2C _n and 100 minutes is required for concentration,
Obtain the above chromatogram n times per minute.

<Effects of the Invention> As described above in detail, in the anion analyzer of the present invention, a plurality of switching valves equipped with a concentration column are provided in series in the flow path for supplying the eluent to the separation column, and the concentration is completed. The measured liquid concentrated from the switching valve having the concentrated column
Since the eluent is sent to the separation column, it is possible to continuously measure a plurality of extremely low concentration liquids to be measured in a short time.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view of an ion analyzer for explaining an embodiment of the present invention, and FIG. 2 is a time chart for explaining an operation of the embodiment of the present invention. 1A, 1B, 1C _{1 to} 1C _n …… Vessel 2A, 2B, 2C _{1 to} 2C _n …… Liquid transfer pump 3B, 3C _{1 to} 3C _n …… Switching valve 4C _{1 to} 4C _n …… Concentration column 5 …… Separation Column, 6 ... Detector 7 ... Constant temperature bath

Claims (1)

[Claims] 1. An anion analyzer for guiding a concentrated solution to be measured to a separation column by a melt to separate anions in the solution to be measured into a chromatograph and analyzing anions eluted from the separation column. , The separation column is provided in series connection to the flow path for supplying the eluent, and each has a concentration column for concentrating the liquid to be measured, and by switching the valve, the liquid to be measured is transferred to the concentration column. Concentrated liquid to be measured from a switching valve that has a plurality of switching valves that switch to the flow channel and that also switches the liquid to be measured concentrated in the concentration column to the flow channel on the separation column side Is sequentially sent to the separation column by the eluent, the anion analyzer.