JP5696311B2 - Organic compound dissolved amount measuring device - Google Patents

Description

  The present invention relates to an organic compound dissolved amount measuring apparatus for measuring the dissolved amount of an organic compound contained in a liquid such as water.

  Conventionally, liquid chromatography is known as a method for measuring a substance soluble in a liquid solvent. This method is a highly sensitive and highly accurate qualitative quantitative analysis method, but the apparatus becomes large and the handling becomes complicated. Therefore, when it is not necessary to specify the chemical substance, the concentration is calculated by measuring the conductivity in the solvent in order to shorten the analysis time.

  However, since only the electrolyte substance is detected, the concentration of the organic compound or the like in the non-electrolyte substance cannot be measured. In such a case, for example, the water to be measured adsorbed on the n-type semiconductor catalyst film is irradiated with light from a light source, and a change in the amount of halogen ions released by oxidative decomposition is detected as a potential difference from the reference electrode. Thus, a method for quantifying a measurement target compound is known (for example, see Patent Document 1).

JP 2002-014078 A

  However, in the conventional case, since ion decomposition is performed by irradiating light, it is necessary to irradiate light according to the substance, which is inconvenient. The present invention has been made in view of the above circumstances, and an object thereof is to provide an organic compound dissolved amount measuring apparatus capable of easily and quickly measuring the amount of an organic compound in a liquid solvent.

The present invention employs the following means in order to solve the above problems.
The organic compound dissolved amount measuring apparatus according to the present invention includes a liquid sample supply unit having a storage unit in which a liquid sample in which an organic compound is dissolved is stored, and a heating unit that vaporizes the sample stored in the storage unit. An ozone addition dilution section for supplying ozone gas and a standard gas to the vaporized sample, an OH radical generation reaction section for generating OH radicals from the ozone gas and reacting with the sample, and a change in the concentration of the OH radicals with time. And an OH radical detector to be measured.

  The present invention dilutes a vaporized sample by adding a standard gas together with ozone gas, generates OH radicals from the added ozone gas, and reacts with the organic compound in the sample from the lifetime of OH radicals that decay. The amount of compound, that is, the amount of organic compound in the sample is calculated.

  The organic compound dissolved amount measuring apparatus according to the present invention is the organic compound dissolved amount measuring apparatus, further comprising an additional flow rate adjusting unit that additionally adjusts the supply amount of the standard gas supplied by the ozone addition dilution unit. It is characterized by.

  In the present invention, when the amount of organic compound in the sample is larger than the amount of OH radicals generated in the OH radical generation reaction unit, the amount of standard gas to be supplied is increased so that OH radicals are generated in the OH radical generation reaction unit. Dilute the sample to the extent that it can survive.

  The water quality diagnosis method according to the present invention is a water quality diagnosis method using the organic compound dissolved amount measuring apparatus according to the present invention, and includes a heating step for vaporizing water to be diagnosed, and ozone gas in the vaporized water. And an ozone addition dilution process for supplying standard gas, an OH radical generation reaction process for generating OH radicals from the generation of the ozone gas and reacting with the water, and OH radical detection for measuring temporal changes in the concentration of the OH radicals And a calculation step of calculating the amount of the organic compound contained in the sample from the time change.

  According to the present invention, the amount of an organic compound in a liquid solvent can be measured easily and quickly. Moreover, the time change of the concentration of OH radicals can be measured regardless of the amount of the organic compound in the sample.

It is a schematic diagram which shows the water quality diagnostic apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the ozone addition dilution part in the water quality diagnostic apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the water quality diagnostic method which concerns on one Embodiment of this invention.

An embodiment according to the present invention will be described with reference to FIGS.
A water quality diagnostic apparatus (organic compound dissolved amount measuring apparatus) 1 according to the present embodiment includes a liquid sample supply unit 2, a heating unit 3, an ozone addition dilution unit 5, an OH radical generation reaction unit 6, and an OH radical detection unit. 7 and a control unit 8.

The liquid sample supply unit 2 includes a storage unit 10 that stores water (liquid sample) W in which organic compounds such as agricultural chemicals and detergent components are dissolved, a pipe 11 that communicates the storage unit 10 and the heating unit 3, and And a moving gas supply unit 12 for transferring a predetermined amount of water W to the heating unit 3. The moving gas supply unit 12 supplies, for example, a predetermined amount of nitrogen gas N ₂ to the storage unit 10 based on an instruction from the control unit 8.

  The heating unit 3 includes a vaporization chamber 13 communicated with the pipe 11 and a first heater 15 that covers the vaporization chamber 13. Then, the water W transferred from the storage unit 10 to the vaporizing chamber 13 is heated by the first heater 15 and vaporized.

For example, the ozone addition dilution unit 5 is supplied with a standard gas ZG that is a zero-adjustment standard gas composed of only nitrogen gas N ₂ and oxygen gas O _2, and generates ozone gas from oxygen gas in the standard gas ZG. An ozone generation unit 16 and a gas flow rate adjustment unit 17 that communicates with the ozone generation unit 16 and adjusts the supply amount of the standard gas ZG necessary for ozone gas generation are provided.

  The ozone addition dilution unit 5 is connected between the heating unit 3 and the OH radical generation reaction unit 6 and supplies ozone gas and the standard gas ZG to the water W vaporized by the heating unit 3. Here, the ozone addition dilution unit 5 includes a plurality of additional gas flow rate control units (additional flow rate control units) 20 communicated with the outlet side pipe 18 of the ozone generation unit 16 and valves 21 corresponding to the respective additional gas flow rate control units. May be. For example, in this embodiment, three additional gas flow rate control units 20 are arranged. These additional gas flow rate adjusting units 20 dilute the water W with the standard gas ZG in order to suppress the decay rate of the OH radicals within a predetermined range and increase the measurement resolution.

  Here, in order to suppress the contamination of the standard gas ZG as much as possible, a mechanical power source such as a pump is not arranged in the supply system of the standard gas ZG.

  The OH radical generation reaction unit 6 is, for example, the same as that described in “Diagnosis of urban air quality by OH radical lifetime observation”, Ayako Yoshino et al., Journal of Atmospheric Environment, Vol. 40, No. 1, A vacuum chamber 22, a second heater 23 wound around the vacuum chamber 22, and a laser irradiation unit (not shown) disposed in the vacuum chamber 22 are provided. Then, OH radicals are generated from the water W and ozone gas and reacted with the water W.

  The OH radical detection unit 7 is arranged in communication with the OH radical generation reaction unit 6. For example, the time of the OH radical concentration in the OH radical generation reaction unit 6 using a laser induction method as described in the above document. Measure changes.

  The control unit 8 controls the amount of nitrogen gas for transferring a predetermined amount of water W to the vaporization chamber 13 in the moving gas supply unit 12 and controls the amount of standard gas ZG in the gas flow rate adjustment unit 17. Further, the disappearance rate of the OH radical is calculated from the time change of the OH radical concentration detected by the OH radical detector 7, and various organic compounds measured in advance, for example, as in the method described in the above document The total amount of organic compounds in the water W is quantitatively calculated by applying the relationship between the concentration of OH and the lifetime of OH radicals.

Next, a water quality diagnostic method by the water quality diagnostic apparatus 1 according to the present embodiment will be described.
The water quality diagnosis method according to the present embodiment includes a heating step (S01) for vaporizing water W to be diagnosed, an ozone addition dilution step (S02) for supplying ozone gas and standard gas ZG to the vaporized water, and ozone gas. OH radical generation reaction step (S03) in which OH radicals are generated and reacted with water, OH radical detection step (S04) for measuring the time change of the concentration of OH radicals, and water W is contained from this time change. And a calculation step (S05) for calculating the amount of the organic compound.

In the heating step (S01), first, water W to be diagnosed is put into the storage unit 10. Then, a predetermined amount of nitrogen gas N ₂ is supplied to the storage unit 10 by the moving gas supply unit 12, and a part of the water W corresponding to the supply amount is transferred to the vaporization chamber 13. Then, the water W in the vaporizing chamber 13 is heated and vaporized by the first heater 15.

  In the ozone addition dilution step (S02), the gas flow rate adjustment unit 17 of the ozone addition dilution unit 5 supplies a predetermined amount of standard gas ZG to the ozone generation unit 16. Then, the ozone generator 16 generates ozone gas from oxygen in the standard gas ZG by a known method.

  And it transfers to the OH radical production | generation reaction process (S03), the ozone gas produced | generated in the ozone addition dilution part 5 and the standard gas ZG are supplied to the vaporized water W, and these mixed gas is produced | generated. And in the OH radical production | generation reaction part 6, ozone gas is photodegraded by a well-known method, and OH radical is generated.

  At this time, the OH radicals are attenuated by reacting with the organic compound in the mixed gas in the vacuum chamber 22. In the OH radical detection step (S04), the OH radical detector 7 is excited by irradiating laser light, and the emitted fluorescence is detected and measured by a photomultiplier tube, etc., and the time change of the OH radical concentration is measured. To do. Thus, the process proceeds to the calculation step (S05) to calculate the lifetime of the OH radical.

  At this time, if the decay rate of the OH radical is large, it is considered that the amount of the organic compound in the mixed gas is too large. Therefore, when supplying ozone gas from the ozone addition dilution unit 5, based on the instruction of the control unit 8, the additional gas flow rate adjustment unit 20 is sequentially operated to increase the supply amount of the standard gas ZG and further dilute, The control unit 8 performs correction according to the amount.

  That is, when the flow rate of nitrogen gas supplied in the heating step (S01) is Qw, the addition flow rate of ozone gas added in the ozone addition dilution step (S02) is Qo3, and the flow rate of the standard gas ZG is Qzg, Since the total gas flow rate Qt is Qw + Qo3 + Gzg, the dilution rate n is Qw / Qt. Initially, the dilution rate n is set to a certain value as a default. And when the measured value (τmeans) when actually measuring the OH radical lifetime is lower than the lower limit value (τmax) of the measurable OH radical lifetime, the dilution ratio n is changed so as to exceed τmax. The above steps are repeated again.

  Thus, the value calculated from the relational expression of τmeans × n is set as the apparent lifetime (τsample) of the OH radical that decays when reacted with the organic compound in the water W. Then, the difference (τsample−τstandard) from the previously measured OH radical lifetime (τstandard) of the sample water (for example, pure water) as a reference in advance is attenuated when reacted with the organic compound in the water W. The water quality diagnosis of the water W is performed from this magnitude as the lifetime of the true OH radical (τtrue).

  According to this water quality diagnostic apparatus 1, the standard gas ZG is added to the vaporized water W and diluted with ozone gas, and OH radicals are generated from the added ozone gas and attenuated when reacted with an organic compound in the water W. The radical lifetime (τsample) can be measured. Then, the water quality diagnosis of the water W can be performed by calculating τtrue as described above. At this time, the OH radical lifetime can be converted into a specific one kind of organic compound concentration (for example, benzene conversion concentration), and the amount of the reacted organic compound, that is, the total amount of the organic compound in the water W is quantitatively calculated. can do.

  In particular, the ozone addition dilution unit 5 includes an additional gas flow rate adjustment unit 20 that additionally adjusts the supply amount of the standard gas ZG to be supplied. Therefore, when the amount of the organic compound in the water W is larger than the amount of OH radicals generated in the OH radical generation reaction unit 6, the amount of the standard gas ZG to be supplied is increased and the inside of the OH radical generation reaction unit 6 is increased. The sample can be diluted to such an extent that OH radicals can remain. Regardless of the amount of the organic compound in the water W, it is possible to measure the temporal change in the concentration of OH radicals.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the ozone addition / dilution unit 5 includes the three additional gas flow rate adjustment units 20. However, the present invention is not limited to this, and can be determined from the relationship between the amount of the sample to be measured and the decay rate of the OH radicals. That's fine.

1 Water quality diagnostic equipment (organic compound dissolved amount measuring equipment)
2 liquid sample supply unit 3 heating unit 5 ozone addition dilution unit 6 OH radical generation reaction unit 7 OH radical detection unit 8 control unit 10 storage unit 20 additional gas flow rate adjustment unit (additional flow rate adjustment unit)
W Water (sample)
ZG standard gas

Claims (3)

A liquid sample supply unit having a reservoir for storing a liquid sample in which an organic compound is dissolved;
A heating unit for vaporizing the sample stored in the storage unit;
An ozone addition dilution section for supplying ozone gas and standard gas to the vaporized sample;
An OH radical generation reaction unit that generates OH radicals from the ozone gas and reacts with the sample;
An OH radical detector for measuring a change in the concentration of the OH radical over time;
A control unit for calculating the amount of the organic compound contained in the sample from the time change;
An organic compound dissolved amount measuring apparatus comprising:   The organic compound dissolved amount measuring apparatus according to claim 1, wherein the ozone addition dilution unit includes an additional flow rate adjusting unit that additionally adjusts a supply amount of the standard gas to be supplied. A water quality diagnosis method using the organic compound dissolved amount measuring apparatus according to claim 1 or 2,
A heating step for vaporizing water to be diagnosed;
An ozone addition dilution process for supplying ozone gas and standard gas to the vaporized water;
An OH radical generation reaction step of generating OH radicals from the ozone gas and reacting with the water;
An OH radical detection step for measuring a change with time in the concentration of the OH radical;
A calculation step of calculating the amount of the organic compound contained in the sample from the time change;
A water quality diagnostic method characterized by comprising:

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