JPH08110295A - Non-fluorescence cell, its production and reforming method - Google Patents

Abstract

PURPOSE: To obtain a cell superior in adhesion strength without emitting fluorescence by excitation light of arbitrary wavelength by using synthetic quartz glass of high purity without emitting fluorescence by specific excitation wavelength at least on an excitation light irradiation face. CONSTITUTION: If annealing treatment of a cell without fluorescence is performed in a clean gas environment such as oxygen gas in a quartz glass furnace tube for a long time, adhesion strength may be increased without emitting fluorescence. For instance, if similar treatment is performed in chlorine gas, oxygen gas or helium gas of high purity even though the cell emits fluorescence, the fluorescence can be eliminated, and a non-fluorescence cell with increased adhesion strength than ever can be obtained. The fluorescence is not produced in an excitation wavelength of 200-500nm, it can be eliminated even if the cell is annealed for a long time, the fluorescence produced on the cell on which the fluorescence emits after bonding of members themselves at the time of cell assembly can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell for a spectrophotometer used for physics and chemistry, more specifically, a non-fluorescent cell used for measuring the fluorescence of a liquid to be detected, a method for producing the same and a modification thereof. Regarding the quality method.

[0002]

2. Description of the Related Art A spectrophotometer cell is used for various optical analyses, and various shapes and materials are used depending on the wavelength used and the object to be measured. Of these, the quartz glass cell is excellent for use in the ultraviolet wavelength range, and in addition to measuring the transmittance and absorbance of the measured object, the measured object in the cell is excited by ultraviolet rays and emitted. It is also used when measuring fluorescence.

As a cell used for these, if fluorescence is generated in the cell body, the fluorescence overlaps with the fluorescence of the sample itself, and accurate measurement cannot be performed. Therefore, a non-fluorescence cell is required. Quartz glass is used for this non-fluorescent cell,
At least the excitation light irradiation surface is made of synthetic quartz glass that does not generate fluorescence.

[Problems to be Solved by the Invention]

However, in recent years, with the advancement of semiconductor technology and medical technology, it is indispensable to provide products corresponding to high-purity analysis, and a fluorescence analysis cell for examining the fluorescence of a sample has higher accuracy and higher quality than ever before. I need it.

Synthetic quartz glass does not fluoresce when it is a material, but it sometimes emits weak green fluorescence with excitation light of 254 nm during cell processing. For this reason, in order to obtain a non-fluorescent cell for high-purity analysis in recent years, cells that do not have fluorescence and have a predetermined intensity are selected and manufactured at the final processing stage. It has a low quality.

In addition, when the members are bonded together in an electric furnace while applying pressure to the bonding surfaces during cell assembly, the bonding surfaces may not be completely adhered and adhesion marks may occur. It was confirmed that the bonding marks can be re-bonded to each other by annealing for a long time to eliminate the bonding marks, but the annealing for a long time causes fluorescence and conversely induces stains. Therefore, if the adhesive strength is increased, a non-fluorescent material does not occur, and the adhesive strength and the non-fluorescent material have a contradictory relationship, and the adhesive strength of the non-fluorescent cell is weaker than that of other cells. It was Therefore, it has been desired to provide a non-fluorescent cell in which the cell adhesion strength is increased while suppressing the generation of fluorescence.

[0007] Further, by firing the electric furnace under vacuum at a temperature higher than the annealing temperature for several hours, contamination caused by evaporation of metal impurities from the furnace wall, which is considered to be a factor of fluorescence generation, is removed in advance to generate fluorescence. However, there is a problem in that not only the apparatus becomes large-scale, but also contact with the furnace bottom is unavoidable, and the fluorescence generation is prevented with good reproducibility.

Further, conventionally, the suppression of the fluorescence generation of the cell has been focused on suppressing the fluorescence at the material stage, and the synthetic quartz glass itself has been studied, but the fluorescence was generated in the actual assembly for some reason. At times, there was no suitable modification method for eliminating the fluorescence in the post-treatment.

The present invention stably provides a cell having excellent adhesive strength that does not fluoresce with excitation light of an arbitrary wavelength, and solves problems such as reduction in yield due to fluorescence generation and productivity. It is also an object of the present invention to provide a method for modifying a cell when fluorescence is generated in an actual assembly.

[0010]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of earnest research to solve the above problems, in the quartz glass furnace core tube, it was found that a non-fluorescent cell can be obtained by heat treatment in a clean gas atmosphere isolated from the furnace atmosphere. As a result of detailed analysis, the fluorescence that was not in the material is generated after the bonding of the members during cell assembly, and even in the cell where the fluorescence is generated, high purity gas in the presence of chlorine, helium gas, or The present invention has been completed based on the finding that if the same heat treatment is performed in the presence of oxygen gas, the generated fluorescence is eliminated and a non-fluorescent cell having an increased adhesive strength can be easily obtained. Hereinafter, the present invention will be described in detail.

The members can be bonded to each other by welding with an oxyhydrogen flame or heating with an electric furnace while applying pressure to the bonding surface. In welding, in order to remove strain during processing, annealing must be performed in an electric furnace as a post-treatment, and both methods perform heat treatment in the electric furnace.

After the heat treatment, the surface of the synthetic quartz glass in which fluorescence was generated was dissolved in HF and analyzed. As a result, an increase in Fe, Ca, K and Cu was observed, and the cause of fluorescence was the electric furnace atmosphere. It was confirmed that the contamination was due to trace metal impurities inside.

Therefore, in order to prevent this contamination, a quartz furnace core tube is manufactured as a standard product, and high-purity nitrogen gas, high-purity oxygen gas, quasi-medical air, helium, argon, high-purity in the presence of chlorine are provided inside. When the annealing treatment was performed while flowing the respective gases, no fluorescence was generated. This is because there is no contamination of trace metal impurities by shutting off from the atmosphere in the furnace, the content of metal impurities in the gas used is less than a few PPm, and the gas is not sealed like in an electric furnace, but in one direction. It is considered that because the gas atmosphere was made to flow to, it was possible to always maintain a fresh and clean atmosphere and no pollution occurred. The material of the furnace core tube used is preferably a high-purity anhydrous product because of contamination of the furnace core tube itself with impurities and heat resistance.

As a result of observing the gas to be used and the fluorescence generation in detail, for the fluorescence prevention, a high-purity gas such as nitrogen gas, oxygen gas, quasi-medical air, helium, argon or chlorine should be flown for the purpose of blocking. However, it was confirmed that even high-purity oxygen and helium, which generate fluorescence, have a weaker fluorescence intensity and are more effective. When high-purity oxygen and helium were further annealed, the fluorescence disappeared. This is because oxygen causes surface oxidation and relaxation of structural defects.
It is also considered that helium has the effect of diffusing into the quartz glass and driving out impurities. It is preferable to use oxygen gas in terms of cost.

Performing welding and heat treatment while applying pressure to the bonding surface in the quartz glass furnace core tube requires equipment similar to a semiconductor manufacturing apparatus, which is expensive and complicated in workability. However, in the current process, since heat treatment is performed in an electric furnace atmosphere, the generation of fluorescence is unavoidable as described above.To manufacture a non-fluorescent cell, after heat treatment, the surface is polished and the surface is polished in a later process. The final product is selected as a product by shaving to eliminate contaminated parts and removing fluorescent light, resulting in a poor yield.

In order to solve these productivity problems, the cell in which fluorescence was generated by adhesion was heat-treated in HC1 gas with the atmosphere in the furnace core tube as O ₂ carrier, and the contaminated portion was purified by chlorine. The fluorescence is gone. From this, high-purity chlorine gas, hydrogen chloride gas, chlorine compound gas, etc. in which the final heat treatment was cut off from the electric furnace atmosphere without changing the current production process of performing heat treatment in an ordinary electric furnace. In the atmosphere of chlorine,
It was found that a 100% non-fluorescent cell was obtained and the yield was significantly improved. Also, like this, high purity,
It has been found that a non-fluorescent cell can be obtained by subjecting oxygen and helium gas to heat treatment for a long time in each atmosphere.

According to the present invention, if a cell having no fluorescence is surely annealed for a long time in a quartz glass furnace core tube in a clean gas atmosphere such as oxygen gas by using a simple apparatus,
It is possible to increase the adhesive strength without generating fluorescence, and even if fluorescence is generated in the cell, the fluorescence can be eliminated by performing the same treatment in the presence of high-purity chlorine, oxygen gas, or helium gas. It has become possible to obtain a non-fluorescent cell with an increased adhesive strength.

As the atmosphere during the heat treatment, it is preferable to use high purity nitrogen gas, oxygen gas, chlorine gas, hydrogen chloride gas, argon gas, helium gas or quasi-medical air. The total amount of elemental impurities is a fine PPm or less, and PPb level is more preferable. The term "quasi-medical air" means pure air from which microorganisms and the like are removed, and commercially available air can be used.

The atmospheric condition during the heat treatment is only required to flow a clean gas such as oxygen in order to shut off the inside of the furnace core tube from the atmosphere inside the electric furnace. Flowing a large flow rate is not preferable because it lowers the temperature inside the furnace core tube. However, a sufficient effect can be obtained with chlorine having a concentration of about 5 vol% as the chlorine present in the blocked atmosphere.

The heat treatment temperature is preferably 900 to 1400 ° C. If the temperature is lower than 900 ° C., the synergistic effects of annealing, purification, and increase in adhesive strength are not recognized, and if it exceeds 1400 ° C., the cell shape is annealed. Not preferable for holding.

Further, according to the present invention, in addition to at least the excitation light irradiation surface, for example, the light incident surface, 90 ° with respect to the incident direction.
The light emitting surface to be used can be used as a cell for fluorescence analysis using the synthetic quartz glass of the present invention, and any surface of the cell or the whole can be obtained by the present invention.

[0022]

According to the present invention, 200 nm to 500 nm
The fluorescence can be eliminated even in cells that have been fluorescently generated by annealing for a long time without generating fluorescence at the excitation wavelength of nm, and can also be generated in cells that have fluorescently generated after the members are bonded together during cell assembly. You can eliminate the fluorescence that you were doing,
Non-fluorescent cells with higher adhesive strength than ever can be manufactured with high yield.

[0023]

[Examples] Specific examples will be described below. In addition,
Fluorescence means green fluorescence with excitation of ultraviolet light at 254 nm.

Example 1 Synthetic quartz glass material (manufactured by Nippon Quartz Glass Co., Ltd.)
A 6-side polished product having a size of 2.5 mm × 12.5 mm × 40 mm was manufactured. Put this in a high-purity anhydrous silica glass furnace core tube,
Annealing treatment (1150 ° C., 1 Hr keep) was performed while flowing high-purity nitrogen gas at 3 liter / min, but no fluorescence was observed. Similarly, fluorescence was not generated even in a high-purity atmosphere of oxygen gas, quasi-medical air, helium gas, argon gas, chlorine gas, or hydrogen chloride gas.

Comparative Example 1 1 with synthetic quartz glass material (manufactured by Nippon Quartz Glass Co., Ltd.)
A 6-side polished product having a size of 2.5 mm × 12.5 mm × 40 mm was manufactured. This is put in an electric furnace and annealed (1150
When it was kept at 1 ° C. for 1 hour, fluorescence was generated. When the block surface where fluorescence was generated was dissolved with HF and atomic absorption analysis was carried out, contamination of Fe, Ca, K and Cu was recognized on the surface. The results are shown in Table 1.

[Table 1]

Example 2 Synthetic quartz glass material (manufactured by Nippon Quartz Glass Co., Ltd.) in which fluorescence was generated by annealing treatment 12.5 mm × 12.5 mm × 4
Long-term annealing conditions (1200 mm) were used to put a 0 mm 6-side polished product in a high-purity anhydrous silica glass furnace core tube to increase the adhesive strength.
° C., was carried 2Hr keep, HC1 0.99 milliliters / min thereafter 16 ° C. / Hr cooled to 900 ° C.), the process in an atmosphere of carrier O ₂ 3 liters / min. HC
In No. 1, only the temperature was raised and the keeping time was passed, and when the temperature was lowered, only O ₂ was passed. As a result, the fluorescence disappeared.

Example 3 According to Example 2, 150 ml of Cl ₂ / mi
n, carrier N ₂ 3 liter / min atmosphere for a long time under annealing conditions (1200 ° C., 2 hr cap, then 90 min.
The treatment was carried out up to 0 ° C. at 16 ° C./Hr temperature decrease). Cl ₂
Was flowed only during the temperature rise and the cape time, and only N ₂ was flowed during the temperature decrease. As a result, the fluorescence disappeared.

Example 4 In accordance with Example 2, treatment was carried out in an atmosphere of O ₂ 3 liter / min for a long period of time under annealing conditions (1200 ° C., 4 Hr cap, then 900 ° C., 16 ° C./Hr temperature decrease). I did.
O ₂ was made to flow from the temperature increase to the temperature decrease. As a result, the fluorescence disappeared.

Example 5 Out of 300 defective LC cells (flow cells for fluorescence analysis) having a bonding mark on the bonding surface, 75 of each were tested as in Example 2.
Hydrogen chloride gas according to Example 3, chlorine gas according to Example 3, oxygen gas according to Example 4, and helium gas instead of oxygen gas in Example 4 were used for the respective treatments. As a result, hydrogen chloride gas and chlorine gas are 2
Hr, oxygen gas was 4 Hr, and helium gas was 4 Hr, and the total number of fluorescence was not generated, and the remaining adhesion mark on the adhesion surface was also eliminated.

Claims (6)

[Claims] 1. An excitation light irradiation surface of at least 200 nm
A non-fluorescent cell made of synthetic quartz glass that maintains high purity and does not generate fluorescence at an excitation wavelength of 500 nm to 500 nm. 2. A method for manufacturing a non-fluorescent cell, which comprises heat-treating in a quartz glass furnace core tube in a clean gas atmosphere isolated from the furnace atmosphere. 3. The clean gas atmosphere is a high-purity atmosphere of any one of oxygen gas, nitrogen gas, quasi-medical air, helium gas, argon gas, and gas in the presence of chlorine. 2. The method for producing a non-fluorescent cell according to 2. 4. The synthetic quartz glass cell, in which fluorescence is generated by the annealing treatment, is further heat-treated in a high-purity gas in the presence of chlorine, a helium gas, or an oxygen gas atmosphere. Method for modifying non-fluorescent cell. 5. A method for reforming a non-fluorescent cell, which comprises heat-treating the cell itself having a bond mark on the bonding surface in a quartz glass furnace core tube in a clean gas atmosphere which is shielded from the atmosphere in the furnace. 6. The method for reforming a non-fluorescent cell according to claim 5, wherein the clean gas atmosphere is a high-purity atmosphere of any one of oxygen gas, helium gas, and chlorine gas.