JP2701740B2 - Total reflection absorption spectrum measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a total reflection absorption spectrum.

[0002]

2. Description of the Related Art Attenuated Total Reflection
ance) The principle of the sample analysis by the spectrum measuring device is as follows. A prism (ATR prism) made of a substance having a higher refractive index than the sample is brought into close contact with the surface on which the sample is to be analyzed, and the entire surface is moved from the ATR prism side toward the interface between the ATR prism and the sample analysis surface. Infrared rays are incident at an incident angle equal to or greater than the reflection critical angle. Under this condition, the infrared rays undergo total reflection at the interface, but penetrate slightly (a fraction of the measured infrared wavelength) beyond the interface to the sample side, and undergo inherent absorption by the surface portion of the sample. . Therefore, the sample can be analyzed by analyzing the absorption spectrum of the reflected infrared light.

[0003]

In a total reflection absorption spectrum measuring apparatus, a liquid sample is analyzed by bringing a liquid sample into contact with a reflection surface of an ATR prism, and a solid sample is analyzed by pressing a solid sample. be able to. As shown in FIG. 5, a conventional measuring unit 40 for measuring a liquid sample is composed of a container 41 having an ATR prism 42 embedded at the bottom. At the time of measurement, a liquid sample 48 is placed in a container 41, and infrared light is incident from a light source 46 disposed below the measuring unit 40 toward the reflection surface 42 a of the ATR prism 42, and the infrared light reflected by absorption is detected by a detector 47. To detect. As described above, in the measurement unit 40 for measuring the liquid sample, the reflection surface 4 of the ATR prism 42 is used.
Since the container 41 exists on the 2a side, the large solid sample is A
It cannot be brought into contact with the TR prism 42. what if,
If the container 41 is made large so that a large solid sample can be brought into close contact with the ATR prism 42, a large amount of liquid sample is required when measuring the liquid sample. For this reason, in the conventional total reflection absorption spectrum measuring apparatus, a measuring unit for measuring a liquid sample and a measuring unit for measuring a solid sample are separately prepared.

Further, in the conventional measuring unit 40 for measuring a liquid sample, after the measurement of one liquid sample is completed, the previous sample is measured by the reflection surface 42a of the ATR prism 42 in order to measure another type of liquid sample. It was necessary to remove the measuring unit 40 from the measuring device in order to completely wash away from the measuring device.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to measure both a solid sample and a liquid sample with one measuring unit. Another object of the present invention is to provide an apparatus for measuring a total reflection absorption spectrum in which a reflecting surface can be easily cleaned.

[0006]

A total reflection absorption spectrum measuring apparatus according to the present invention, which has been made to solve the above problems, has an ATR prism with a reflecting surface slightly protruding substantially vertically upward. A measurement unit having a fixed prism fixing part and a drainage groove provided around the prism fixing part is provided.

[0007]

When measuring a liquid sample, a small amount of the liquid sample is dropped on the reflection surface of the ATR prism so that the liquid sample covers the infrared incident area of the reflection surface. Here, the liquid sample may be spread on the reflection surface by placing a holding plate from above the liquid sample dropped on the reflection surface. When measuring a solid sample, the measurement surface of the solid sample is pressed against the reflection surface of the ATR prism. In the measuring unit of the total reflection absorption spectrum measuring apparatus according to the present invention, since there is only a groove (drainage groove) around the reflection surface (the groove is naturally lower than the height of the reflection surface), it is a large solid. Even if it is present, it does not mean that it cannot be adhered to by being hindered by the wall of the container unlike the conventional measuring unit.

When another liquid sample is measured, a cleaning liquid can be dropped onto the reflection surface of the ATR prism while the measuring unit remains intact to wash away the previous liquid sample. The cleaning liquid flows out into a drain groove around the reflection surface and does not remain on the reflection surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A measuring unit of a total reflection absorption spectrum measuring apparatus according to an embodiment of the present invention will be described with reference to FIGS. The measuring unit 10 of this embodiment is circular as shown in FIG. 2, and a material (for example, a stainless steel plate, a hard plastic plate, or the like) that does not corrode various liquid samples is used for the main body. . A in the center of the body
A flat portion 11 to which the TR prism 12 is fixed is formed, and a drain groove 13 for discharging a cleaning liquid or the like is formed around the flat portion 11. As shown in FIG. 1, the ATR prism 12 is embedded so as to slightly protrude from the flat portion 11.
A drain hole 14 is provided at one or more locations (one location in FIG. 2) at the bottom of the drainage groove 13.

When a liquid sample is measured by the measuring unit 10 of this embodiment, first, a liquid sample 18 is dropped on the reflection surface 12 a of the ATR prism 12. When a sufficient amount of liquid sample can be used, a slightly large amount of liquid sample is dropped on the reflecting surface 12a so as to cover almost the entire reflecting surface 12a. When a sufficient amount of the liquid sample cannot be secured, a small amount of the liquid sample 18 is dropped on the reflecting surface 12a, and the holding plate 15 is placed thereon to spread the liquid sample on the reflecting surface 12a. Since the penetration depth of the measurement infrared ray into the sample is small, the thickness of the liquid sample on the reflection surface 12a may be sufficiently small.
In consideration of a case where the pressing plate 15 comes into direct contact with the reflection surface 12a of the ATR prism 12 due to interruption of the connection, it is desirable to use a material (for example, metal) having a small infrared absorption amount for the pressing plate 15.

When the measured liquid sample is washed off the reflecting surface 12a, the cleaning liquid is dropped or discharged onto the reflecting surface 12a while the measuring unit 10 itself is left at that position.
The cleaning liquid containing the liquid sample 18 flows down to the drain 13 and
It is discharged from the drain hole 14. If it is desired to start the measurement of the next sample immediately, warm air may be blown to the reflection surface 12a by a dryer or the like. Measurement unit 10 of the present embodiment
Since there is no wall in the vicinity to block the wind, the drying takes place quickly.

In addition, instead of providing the drain hole 14 at the bottom of the drain groove 13, a drain port having a lowered levee is provided at a part of the outer peripheral side of the drain groove 13, and the measuring unit 10 is inclined by inclining the liquid. The sample 18 and the cleaning liquid may be discharged.

When measuring a solid sample, it is only necessary to press the analysis surface of the solid sample against the reflecting surface 12a of the ATR prism 12. As shown in FIG. 1, the measuring unit 10 of this embodiment has no portion higher than the reflection surface 12a of the ATR prism 12, so that any large solid sample can be brought into close contact with the reflection surface 12a.

[0014]

[0015]

[0016]

[0017]

In the measuring unit of the total reflection absorption spectrum measuring apparatus according to the present invention, since there is only a drain groove around the reflecting surface, it is obstructed by the wall of the container as in the conventional measuring unit. It can measure even a large solid sample without any problem. Further, when measuring another liquid sample after measuring one liquid sample, the cleaning liquid can be dropped on the reflection surface of the ATR prism while the measurement unit is left as it is, and the previous liquid sample can be washed away. Furthermore,
Since there is no wall around the reflection surface, the cleaning liquid is dried quickly.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a measuring unit of a total reflection absorption spectrum measuring apparatus according to one embodiment of the present invention.

FIG. 2 is a plan view of a measurement unit according to the embodiment.

FIG. 3 is a longitudinal sectional view of a conventional measurement unit for measuring a liquid sample.

[Explanation of symbols]

10, 40: measuring unit 11: flat part 12: ATR prism 12a: reflection surface 13: drain groove 14: drain hole 15: holding plate 18: liquid sample

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-138340 (JP, A) JP-A-6-214102 (JP, A) JP-A-5-504626 (JP, A)

Claims (1)

(57) [Claims] 1. A measuring unit having a prism fixing part in which an ATR prism is fixed with a reflecting surface slightly projecting substantially vertically upward, and a drainage groove provided around the prism fixing part. A total reflection absorption spectrum measuring apparatus.