JP2700986B2 - Method for simultaneous determination of multiple inorganic acids - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for simultaneously determining a plurality of types of inorganic acids.

[0002]

2. Description of the Related Art At present, in the chemical industry manufacturing industry, various health problems due to chemical substances and the like have occurred along with the diversification of approval and permission of new substances. Therefore, while applying the Prevention Rules for Specific Chemical Substances (hereinafter abbreviated as specialization rules) in order to prevent these health disorders, the measurement of the concentration of air in the substance used, the evaluation of the measurement results, and the evaluation results It is necessary to take action based on In addition, to contribute to the promotion of hygiene management, while applying from photoelectric spectrophotometry to high-performance liquid chromatography (hereinafter abbreviated as HPLC),
It is also necessary to consider harmonization of work environment measurement and personal exposure measurement for evaluation of measurement results.

[0003] First, under the legal system in both the United States and Japan,
There are assessments of the control category based on the A concentration and B measurement based on the control concentration notified by the Ministry of Labor of Japan and the allowable concentration recommended by the Japan Society for Occupational Health, while the State Labor Bureau in the United States and the American Conference of
Govermental Industrial H
Threshold recommended by ygienists
Limit Value-Time Weighted
Average, TLV-Short Time E
xposure Limit and TLV-Ceilin
g and Occupational Safety a
There is an evaluation of personal exposure monitors based on TWA and Ceiling recommended by ND Health Administration and Direct in France.
ion Regionale Trail
There is t del 1'Employ.

In addition, there is a quality control concerning accuracy and precision in measurement and analysis while complying with the above-mentioned control density and allowable density rules. Specifically, the present inventors have already established HPLC measurement methods for ortho-tolidine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, benzene, benzidine, and phthalic anhydride, and have been implementing sanitary control. Was.

[0005] Further, there is a study of a measuring method for various new drug substances, and simultaneous quantification and interference caused by a matrix. More specifically, the methods for measuring potassium cyanide, hydrogen cyanide, and sodium cyanide used in electrolytic degreasing baths, copper plating baths, and zinc plating baths include a pyridine-pyrazolone method using an existing distilled water absorbing solution. And a method for quantifying a 2,3-dicyanohydroquinone derivative by a HPLC fluorescence method using a p-benzoquinone absorbing solution. As a method of measuring manganese and its compounds commonly used in mixing and molding of dry batteries, there is an atomic absorption spectrophotometry using an existing glass fiber filter, but 1- (2,4-azorilazo) -2-. It has been improved to “stopped flow photoelectric spectrophotometry” using a naphthol complex absorbing solution.

Further, as a method for measuring formaldehyde, acetaldehyde, formic acid and acetic acid used for spray coating and the like, there is an existing chromotropic acid method using distilled water. It has been improved to a chromatographic method. In addition, as a method of measuring diborane and boron trioxide used as impurity doping gas in a Si epitaxial growth furnace, there is an HPLC method using a chromotropic acid absorbing solution, and the hygiene management technology related to the above-described measuring method is being promoted. .

For example, when quantifying an inorganic acid containing an inorganic anion such as a fluorine ion (F ⁻ ) or a chloride ion (Cl ⁻ ), the following quantification method has been widely used. That is, a lanthanum-1,2-hydroxyanthraquino-3-ylmethylamine method (a method of collecting hydrogen fluoride corresponding to a second substance from photoelectric spectrophotometry with 0.01 N sodium hydroxide), thiocyanate Mercuric acid method (method of collecting hydrogen chloride that falls under the category 3 substance and hydrogen bromide that does not fall under the special regulations with distilled water absorption liquid), reduced zinc naphthylethylenediamine method (using nitric acid that falls under the category 3 substance) Method of collecting with 0.1N-sodium hydroxide absorption liquid), molybdenum oxide method (method of collecting phosphoric acid that does not fall under special rules with distilled water absorption liquid)
And a barium chromate suspension method (a method of collecting a sulfuric acid mist corresponding to a third type substance using a glass fiber filter) and the like. These methods of quantifying inorganic anions have been used mainly in metal plating and dry etching of semiconductors, but when multiple types of inorganic anions coexist, they can be simultaneously separated and quantified with high accuracy. It was difficult to do.

As described above, none of the methods proposed so far is suitable for simultaneously quantifying a plurality of types of inorganic acids.

[0009]

SUMMARY OF THE INVENTION The present invention solves such a problem in the conventional quantification method, in which a plurality of types of inorganic acids, which were difficult to quantify simultaneously, can be simultaneously separated with high accuracy. It is an object to provide a separation and quantification method capable of quantification.

The inventor of the present invention has determined that a specific reactive substance
Products produced by the action of
By that, the concentration of inorganic acids from the concentration of inorganic anions
The present inventors have found that high-sensitivity and high-precision rational simultaneous quantification is possible, and completed the present invention. At this time, HPL
Method C, for example, using an analytical method by reversed-phase chromatography, or using a transparent inorganic anion with a high concentration of an ultraviolet absorbing eluent, and electrically measuring the absorbance appearing at a negative peak depth. A simultaneous quantification method is used by a conversion detection method. The present inventor also reexamined a method for collecting hydrogen chloride by an existing method.

[0011]

According to the method of the present invention for simultaneously quantifying a plurality of inorganic acids, a method for simultaneously quantifying a plurality of inorganic acids A ₁ ,
A 2 _- a sample containing an aqueous solution containing potassium hydrogen phthalate in high-performance liquid chromatograph was used as mobile phase
More, the inorganic acids _{A 1, A} 2 -, respectively product
B ₁ , B ₂ --- The separated product B
₁ , B ₂ --- is detected by an ultraviolet detector, and the products B ₁ ,
B 2 _- above inorganic acids A _1, A 2 a calibration curve from the peak area corresponding to _- characterized by quantifying the level of high sensitivity and high accuracy Simultaneous determination was difficult by the conventional method It is possible. That is, the present invention provides a method for controlling the concentration of inorganic acids A ₁ , A ₂
An aqueous solution containing potassium hydrogen phthalate as a mobile phase, and
High-performance liquid chromatograph with UV detector
A product B ₁ , formed from the inorganic acid A ₁ , A _2-
It is calculated from the concentration of B ₂ ---, and the inorganic acid A ₁ ,
When calculating the concentration of A ₂ −−, a special calculation formula is used. The HPLC conditions and the formulas used for calculating the concentration of each substance will be described in detail in Examples below.

Inorganic acids to be measured include F ⁻ ,
Compounds containing an anion such as Cl ⁻ , Br ⁻ , NO ₃ ⁻ , PO ₄ ³⁻ , SO ₄ ²⁻ , for example, sodium fluoride,
There are potassium chloride, potassium dihydrogen phosphate, sodium bromide, sodium nitrate, potassium sulfate and the like. In addition, since these inorganic anions are easily dissolved in water, HPLC
In this case, distilled water is preferable as the mobile phase solvent. Hereinafter, examples of the present invention will be described.

[0013]

[Example] Determination method of inorganic acids Preparation method of reagents Sodium fluoride, potassium chloride, potassium dihydrogen phosphate, sodium bromide, sodium nitrate and potassium sulfate are diluted with distilled water to prepare a standard solution of a predetermined concentration. did.
The distilled water for preparation used was distilled water of ion-exchanged water. For the mobile phase, 0.5 mM potassium hydrogen phthalate, 0.5 mM tetrabutylammonium hydroxide and 1.0 mM 2- (N-morpholino) ethanesulfonic acid hydrate [hereinafter abbreviated as phthalic acid hydrate] And 1
The pH was adjusted to 6.6 with N potassium hydroxide. The reagents used were all manufactured by Wako Pure Chemical Industries.

Measuring Apparatus Shimadzu LC-6A was used for high performance liquid chromatography. The UV detector is Shimadzu SPD-6A type, 267n
m. In the separation column, Shimadzu Shim-pack CLC-ODS (15
0 mm × 6.0 mmφ, particle size 5 μm). The solvent flow rate was 1.5 ml / min, and the column temperature was adjusted to 40 ° C. And midget impinger (liquid volume 30m
1, 178 mm × 28 mmφ) were connected in series in two stages.

Measurement of concentration of inorganic acids 10 ml of the existing absorbing solution was put into a midget impinger, connected in series in two stages, and a sample gas was collected at a flow rate of up to 3.0 liter / min according to the corresponding inorganic acids. . After collection, this absorbing solution was injected into the high performance liquid chromatograph, and the peak area corresponding to each inorganic anion was measured. The inorganic anions concentration in the absorbing solution was determined from each calibration curve while correcting with the corresponding blank value. still,
The concentration of inorganic acids (C, mg / m ³ ) in the sample gas was calculated from the following equation.

C = W (F · 10 n / V) ｛(273 + t) / 273｝ (760 / P) where W: concentration of each inorganic anion (μg / ml),
F: Conversion value when converting the molecular weight of the inorganic anion into the molecular weight of the inorganic acids, that is, 1.05 for HF, 1.03 for HCl, 1.03 for H ₃ PO ₄ , and 1.0 for HBr. 01, 1.02 for HNO ₃ and 1.02 for H ₂ SO ₄ . Also, n: dilution rate of the absorbing solution, V: volume of collected air (liter), t: temperature of the working place (° C.), P: pressure of the working place (mmHg).

Results of Separation Experiment of Inorganic Anions Separation was performed by reverse phase chromatography using an octadecyl silica gel column as a stationary phase and a mobile phase of potassium hydrogen phthalate-ion pair reagent (tetrabutylammonium hydroxide). Was. The inorganic anions in the sample are
It showed great solubility in water. Therefore, 100% distilled water was selected as the mobile phase solvent. The above-mentioned phthalic acid hydrate was used as the ion buffer, and the ionization equilibrium was maintained at pH 6.61. FIG. 1 is a chromatogram in a separation experiment of inorganic anions.

As shown in FIG. 1, when the present invention is used, various inorganic anions can be separated from each other with high resolution. Water injection spikes occurred as late as 14 minutes upon sample injection. A calibration curve was created based on the peak area using each inorganic anion standard solution. The linearity was confirmed from 0 to 10 μg / ml.
Each detection limit is as follows, and F ⁻ is 1 × 10 ^−2.
mg / m ³ , Cl ⁻ is 1 × 10 ⁻² mg / m ³ , Br ⁻
Is 2 × 10 ⁻² mg / m ³ , NO ₃ ⁻ is 2 × 10 ⁻² m
g / m ³ , PO ₄ ^3- is 5 × 10 ⁻² mg / m ³ , SO
_{As for} ^4-2 , analysis of 2 × 10 ⁻² mg / m ³ was possible. In addition, it corresponded when 30 liters of sample gas were sampled.

The collection rate of hydrogen chloride among inorganic ions was measured at room temperature by an existing method. As previously described, with the draft evacuated, on the hot plate in the exposure chamber, 50
The gas evolved under the conditions of ° C and dynamic air flow was collected. Table 1 shows the collection rate of hydrogen chloride.

[0020]

[Table 1]

From this experiment, it was confirmed that hydrogen chloride can be quantitatively collected up to 3.0 liter / min. However, the absorption solution of the existing method did not cause any interference with respect to storage stability.

[0022]

EFFECT OF THE INVENTION By using the method for simultaneous determination of inorganic acids of the present invention, sampling and analysis with significantly higher sensitivity and accuracy compared with the existing method in the management of work environment related to the handling of hazardous substances carried out by business operators. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a chromatogram in a separation experiment of inorganic anions.

Claims (1)

(57) [Claims] 1. A plurality of kinds of inorganic acids A _1, A 2 _- A sample containing an aqueous solution containing potassium hydrogen phthalate and the mobile phase
According to the high performance liquid chromatograph used, the above inorganic acid
_{A1, A} 2 - each product _{B 1, B} 2 - as was <br/> separated and isolated the product _{B 1, B} 2 - UV test the
Each of the inorganic acids A ₁ , A ₂ --- is detected by an extractor, and from the peak areas corresponding to the products B ₁ , B ₂ ---based on a calibration curve.
A method for simultaneously quantifying a plurality of types of inorganic acids, characterized by quantifying the concentration of phenol.