JP2003075310A - Method for analyzing of metal component in high-purity admantanes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for analyzing of metal component in high-purity adamantanes. SOLUTION: After the high-purity admantanes are dissolved in purified methanol, the mixture are mixed with nitric acid solution. The solution is analyzed by an inductive coupling plasma mass spectrometry.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for analyzing adamantane used as a photosensitive resin (photoresist resin) for semiconductor manufacturing or as a drug.

[0002]

BACKGROUND OF THE INVENTION Adamantanes are alicyclic alkanes having a diamond skeleton and are excellent in thermal and chemical stability. Therefore, adamantanes are photosensitive resins for semiconductor production (photoresist resins).
The drug is under development as a pharmaceutical product, and a grade that requires high-purity products with reduced metal impurities is being developed.

For this reason, it is necessary to control the quality of the concentration of metal impurities, but since adamantanes are solid at room temperature, a pretreatment operation is necessary when analyzing metal components. As a pretreatment method for analyzing the metal component in the organic solid, generally, a method of burning and ashing the organic component to dissolve the non-volatile residue in a strong acid aqueous solution, after dissolving in an organic solvent,
There is a method of extracting with a strong acid aqueous solution.

However, in the case of the method of combustion ashing, there are many problems in analysis due to contamination and scattering during operation.
Also, in the extraction method, contamination during operation, extraction loss, generation of waste organic solvent, and the like occur, and in any method, the measurement operation is complicated and accurate quantitative analysis is difficult.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a method for quantitatively analyzing metal components in adamantanes.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that adamantanes are dissolved in purified methanol obtained by contact with a strongly acidic cation exchange resin, and then mixed with an aqueous nitric acid solution, The inventors have found that the metal component in high-purity adamantane can be accurately analyzed by analyzing the solution with an inductively coupled plasma mass spectrometer, and thus the present invention has been accomplished.

That is, the present invention relates to a method for analyzing high-purity adamantane, which comprises dissolving high-purity adamantane in purified methanol, mixing the solution with nitric acid aqueous solution, and analyzing the solution.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The adamantanes analyzed according to the present invention have an adamantane skeleton and are soluble in methanol. Specifically, 3-hydroxy-1-adamantyl methacrylate, 3-hydroxy-
1-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 1-adamantanol, 1.3-adamantane diol and the like can be mentioned.

As the purified methanol of the present invention, Na,
Content of metal components to be measured such as Al, Fe, Mn is 1
ppb or less, preferably 0.2 ppb or less. However, even commercially available EL grades for semiconductors may contain a metal component such as Na in the vicinity of several ppb, which causes a problem that the accuracy of microanalysis decreases.

As a method for reducing metal components such as Na in methanol, there is a method of contacting with a strongly acidic cation exchange resin. The strongly acidic cation exchange resin has a structure having styrene-divinylbenzene as a skeleton and a sulfonic acid group, and has an H-type conversion rate of 99% or more, preferably 99.
A resin having 9% or more is preferable, but it is not particularly limited, and other cation type exchange resins can reduce the metal component.

When measuring an organic solvent with an inductively coupled plasma mass spectrometer, carbon is generated in argon plasma and adheres to a skimmer cone at the introduction part of the mass spectrometer,
Since it interferes with the analysis, a small amount of oxygen is added to the argon gas to carry out an operation to suppress carbon generation.

[0012]

Example 1 Commercially available EL grade (Kanto Chemical Co., Inc.) methanol was used as a strongly acidic cation exchange resin (Mitsubishi Chemical Co., Ltd. Diaion P).
After passing through a column packed with K-228), purified methanol having Na content of 3 ppb to 0.2 ppb or less and other metals of 0.2 ppb or less was obtained.

A 1.2 g sample was precisely weighed and purified methanol 6
It was dissolved in 0 g to give a 2% solution (solution A). A 1.8% nitric acid solution was prepared from ultrapure water and EL nitric acid (solution B). Liquid A,
The following solutions were prepared using solution B. Blank Purified methanol 10 g + B solution 10 g Sample A solution 10 g + B solution 10 g 0.5 ppb standard solution A solution 10 g + B solution 10 g
(Standard solution 1.0 ppb added to solution B) 1.0 ppb standard solution solution A 10 g + solution B 10 g
(Standard solution 2.0 ppb added to solution B) 2.0 ppb standard solution solution A 10 g + solution B 10 g
(4.0 ppb standard solution added to solution B) Each adjustment solution was added to an inductively coupled plasma mass spectrometer (ICP-M
S, Yokogawa HP4500 type), and the metal content was determined from the calibration curve. The results are shown in Table 1.

[0014]

[Table 1] (* 1) 3-hydroxy-1-adamantyl methacrylate (* 2) 3-hydroxy-1-adamantyl acrylate (* 3) 2-methyl-2-adamantyl methacrylate

[0015]

INDUSTRIAL APPLICABILITY According to the present invention, rapid measurement can be performed without complicated pretreatment such as combustion abolition, and accurate trace concentration of metal components in adamantane can be measured.

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Claims (4)

[Claims] 1. A method for analyzing high-purity adamantane, which comprises dissolving high-purity adamantane in purified methanol, mixing the solution with nitric acid aqueous solution, and analyzing the solution. 2. The analysis method according to claim 1, wherein the analysis is performed by an inductively coupled plasma mass spectrometer. 3. The analysis method according to claim 1, wherein the purified methanol is methanol purified by a strongly acidic cation exchange resin. 4. The analysis method according to claim 1, wherein the metal components contained in the high-purity adamantane are analyzed.