JP2002055097A - Method for determination sulfonic acid type anionic surfactant in copper electrolytic solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method, capable of selectively determination a sulfonic acid type anionic surfactant of about 1 ppm in a solution such as an electrolytic solution or a plating solution, containing several - several ten g/l of heavy metal ions and a very small amount of the sulfonic acid type anionic surfactant. SOLUTION: The method for determining the sulfonic acid type anionic surfactant in the electrolytic solution includes a process (1) for treating heavy metal ions contained in the copper electrolytic solution or plating solution with a complex-forming agent, a processing (2) for forming a methylene blue aqueous solution in order to drive a compound soluble in an organic solvent from the water soluble sulfonic acid type anionic surfactant contained in the solution, a process (3) for bringing the treated solution into contact with the methylene blue aqueous solution to form an aqueous solution of a methylene blue complex of the sulfonic acid type anionic surfactant, a process (4) for bringing an aqueous solution of the complex into contact with an organic solvent for forming an extract, a process (5) for measuring the absorbancy of the extract at a measuring wavelength of 650 nm by an ultraviolet spectrophotometer, and a process (6) for inserting the measured absorbancy in the correlation of the sulfonic acid type anionic surfactant and absorbancy to calculate the amount of the sulfonic acid type anionic surfactant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sulfonic acid type anionic surfactant used for a copper electrolyte or a plating solution, and more specifically, to a sulfonic acid type anionic surfactant from a copper electrolyte or a plating solution. The present invention relates to a method for selectively extracting an agent and quantifying the same.

[0002]

2. Description of the Related Art Electrolytic copper is mainly obtained by electrolyzing a sulfated copper electrolytic solution in which copper sulfate is dissolved between an anode and a cathode and electrodepositing copper ions on the cathode.

[0003] In copper electrolysis, uneven electrolysis is a major problem. In order to smooth electrodeposition on the cathode surface,
Normally, trace amounts of organic additives such as glue, thiourea and sulfonic acid type anionic surfactant are added.

[0004] In the prior art, regarding the addition to the copper electrolyte,
For thiourea, the amount of consumption and the timing of addition of thiourea have been quantitatively established, but the method of quantifying sulfonic acid-type anionic surfactants has not been established yet, and the timing of addition has been exclusively determined. And its efficacy has not yet been revealed.

A method for determining a sulfonate-type anionic surfactant in a general aqueous solution not containing heavy metal ions such as copper, nickel and cobalt includes an absorbance method (JIS).
K-0101, JIS K-0102, etc.). According to this, when the concentration level of the sulfonic acid type anionic surfactant was changed and quantified in the range of 0 to 200 μg, the relationship between the concentration level and the absorbance (0 to 0.45) was good. Shows linearity. The use of these determination methods has been studied to determine the amount of the sulfonic acid type anionic surfactant in the copper electrolyte solution. However, in the prior art, the sulfonic acid type anionic surfactant in the copper electrolyte solution has been studied. Has not yet been established until the establishment of a method for quantification.

The following problems are considered to be factors that hinder the determination of the sulfonic acid type anionic surfactant in the copper electrolyte.

[0007] 1) In the above-mentioned quantitative method, in order to perform extraction in a neutral form in which an ion pair is formed, the copper electrolyte is neutralized in advance with sodium hydroxide. The neutralization is performed in order to completely extract the sulfonic acid type anionic surfactant into the organic phase and react with the methylene blue of the quantitative sample. However, hydroxide precipitation of heavy metal ions such as copper, nickel, and cobalt in the copper electrolyte occurs, and the solution becomes muddy at the neutralization point. For this reason, there is a possibility that the reaction between the sulfonic acid type anionic surfactant and methylene blue of the quantitative sample is inhibited, and a negative error is caused with respect to the quantitative value.

2) Even if the sulfonic acid type anionic surfactant reacts with methylene blue to form a methylene blue complex of the sulfonic acid type anionic surfactant, this is adsorbed on the hydroxide precipitate of the heavy metal ion. For this reason, the complex cannot be extracted by the organic solvent for extraction, and a negative error may be caused with respect to the quantitative value.

3) The effect of glue or thiourea can be considered when added together with the sulfonic acid type anionic surfactant. For example, since the copper electrolyte has a very strong sulfuric acid property and is heated at the time of addition, the added electrolyte or its decomposition product gradually decomposes into various amino acids using sulfuric acid as a catalyst. These decomposition products behave in the same manner as the sulfonic acid type anionic surfactant in quantifying the sulfonic acid type anionic surfactant, so that a positive error may be caused in the quantitative value.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for determining a sulfonic acid type anionic surfactant in a copper electrolyte.

Further, the object of the present invention is to provide several g / l to several tens g / l.
About 1 ppm of a sulfonic acid type anionic surfactant can be selectively determined with respect to a solution such as an electrolytic solution or a plating solution containing about 1 heavy metal ion and a trace amount of a sulfonic acid type anionic surfactant. Is to provide a way.

[0012]

The method of the present invention for quantifying a sulfonic acid type anionic surfactant contained in a copper electrolytic solution or a plating solution comprises the following steps.

1) a step of treating heavy metal ions contained in the copper electrolyte or plating solution with a complexing agent to form a treatment solution; 2) a water-soluble sulfonic acid type anion contained in the copper electrolyte or plating solution. A step of adding a fixed amount of methylene blue, which is an ion pair of a sulfonic acid type anionic surfactant, to an aqueous solution in order to derivatize the surfactant into a compound soluble in an organic solvent, 3) producing an aqueous methylene blue solution; Contacting the treatment liquid with the aqueous solution of methylene blue to form an aqueous solution in which a methylene blue complex of a sulfonic acid type anionic surfactant is dissolved; 4) contacting the aqueous solution in which the methylene blue complex is dissolved with an organic solvent; A step of selectively extracting the methylene blue complex into an organic solvent to produce an extract; A step of measuring the absorbance of the discharged liquid with a spectrophotometer, in this case, it is preferable to set the measurement wavelength to 650 nm using an ultraviolet spectrophotometer.

6) inserting the measured absorbance into the correlation between the sulfonic acid type anionic surfactant and the absorbance to determine the amount of the sulfonic acid type anionic surfactant.

The complexing agent is preferably ammonia or ethylenediaminetetraacetic acid. By the addition, heavy metal ions contained in the copper electrolyte or the plating solution are converted to a water-soluble ammine complex. It is desirable to generate an extract at pH 8 or more and pH 12 or less, which is a hydrogen ion concentration range in which the water-soluble ammine complex is stable. In addition, in the absorbance measurement using an ultraviolet spectrophotometer, interference components other than the methylene blue complex of the sulfonic acid type anionic surfactant are scanned in advance with an ultraviolet spectrophotometer to measure the methylene blue complex of the sulfonic acid type anionic surfactant. It is desirable to carry out quantification by selecting an optimal quantification wavelength that does not interfere with the wavelength and can quantify with high sensitivity.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a flow chart of a method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte according to the present invention.

In this method, a step of adding a fixed amount of methylene blue, which is an ion pair of a sulfonic acid type anionic surfactant, to an aqueous solution to form an aqueous methylene blue solution,
It consists of two series, a separating funnel 1 and a separating funnel 2. In separatory funnel 1 and separatory funnel 2, 25 ml of water, 5 ml of alkaline sodium borate, 2.5 ml of methylene blue and 5 ml of chloroform are mixed, immersed, and separated into an aqueous phase and a chloroform phase. Separate, and remove the impurities in methylene blue contained in the aqueous phase using chloroform in advance. At this time, this operation is repeated until no color is formed on chloroform. This aqueous phase is an aqueous methylene blue solution. Also, 1.5 ml of sulfuric acid is added to the separating funnel 2. On the other hand, 10 ml of copper electrolyte or plating solution was adjusted to pH = 11 with aqueous ammonia,
Complexes heavy metal ions.

The aqueous phase obtained in the separatory funnel 1 is mixed with a complexed copper electrolytic solution or plating solution, 5 ml of chloroform is added, and the mixture is immersed to separate into an aqueous phase and a chloroform phase. . The chloroform phase and the aqueous phase obtained by the separating funnel 2 are mixed, immersed, and separated into an aqueous phase and a chloroform phase. The chloroform phase thus obtained is an aqueous solution in which the methylene blue complex is dissolved. The chloroform phase is brought into contact with an organic solvent to make 25 ml,
The absorbance measurement is performed in the UV form.

The present invention is characterized by the following improvements with respect to the determination of a sulfonic acid type anionic surfactant in a copper electrolyte on the premise that the copper electrolyte is neutralized with sodium hydroxide.

1) In order to replace the heavy metal hydroxide precipitate with a water-soluble ammine complex, the pretreatment with sodium hydroxide is changed to a pretreatment with aqueous ammonia.

2) Keep the pretreatment on the alkaline side. Even with the pretreatment with aqueous ammonia, if the pH is about 7, a large amount of hydroxide precipitate remains, so that the hydroxide precipitate is brought into a pH range that completely changes to a water-soluble ammine complex.

Even when treated with aqueous ammonia, initially, hydroxide precipitates are formed, and the ammonia concentration is increased, whereby the counter ions of copper, nickel and cobalt are replaced with ammonia from hydroxyl groups.

3) To quantitatively grasp the interference of components such as glue and thiourea on the determination of the methylene blue complex of the sulfonic acid type anionic surfactant.

The pretreatment of the copper electrolyte with aqueous ammonia to convert the heavy metal into a water-soluble ammine complex, thereby selectively quantifying the sulfonic acid type anionic surfactant in the copper electrolyte. Details will be described below.

1) When the pretreatment of the copper electrolyte is performed with aqueous ammonia and the alkaline side is maintained, the heavy metal in the copper electrolyte becomes a water-soluble ammine complex and hydroxide precipitation does not occur. Therefore, the formation of the methylene blue complex of the sulfonic acid type anionic surfactant is not hindered. Therefore,
The sulfonic acid type anionic surfactant is well extracted into the extraction organic solvent, and the accuracy of the quantitative value is improved.

2) The quantitative determination of the methylene blue complex of the sulfonic acid type anionic surfactant is performed by monitoring the wavelength scan measurement of an ultraviolet spectrophotometer. In the wavelength scan measurement, it is possible to select a wavelength that is not affected by an interference component. Therefore, the accuracy of the quantitative value is increased.

Various factors in the quantification method of the present invention will be described.

1) Determination of Sulfonate-Type Anionic Surfactant in Copper Electrolyte According to the quantitative method of the present invention shown in FIG. The relationship with the absorbance when changing the amount) shows good linearity as shown in FIG.

2) Change of heavy metal contained in copper electrolyte to ammine complex In the pretreatment of copper electrolyte, about 50 ml of aqueous ammonia is added to 10 ml of copper electrolyte by the quantitative method of the present invention shown in FIG. By doing so, most of heavy metals such as copper and nickel contained in the copper electrolyte are changed into ammine complexes and are solubilized.

3) Hydrogen ion concentration in the neutralization treatment of the copper electrolyte In the pretreatment of the copper electrolyte according to the quantitative method of the present invention shown in FIG. The hydrogen ion concentration becomes 11 or more.
It is considered that this hydrogen ion concentration is necessary for changing heavy metals to ammine complexes.

4) Influence of glue contained in copper electrolyte As shown in Table 1, 0 times (measurement blank), 10 times and 100 times the amount of glue added to a normal copper electrolyte were added. When the simulated electrolyte prepared by heating at 80 ° C. for 3 hours was quantified by the method of the present invention, the result of the absorbance at a wavelength of 650 nm of the ultraviolet spectrophotometer was compared with that of the copper electrolyte (without addition of glue or the like). The results are shown in Table 2 together with the results of one example.

[0032]

[Table 1]

[0033]

[Table 2]

When 10 times the amount of glue was added, the absorbance was about the same as that of the measurement blank, and it can be said that the influence on the quantitative determination of the sulfonic acid type anionic surfactant was small.
On the other hand, when glue was added 100 times the amount,
The absorbance is at the same level as that of a normal copper electrolyte, and can be said to have a large effect on the determination of the sulfonate-type anionic surfactant.

Therefore, it can be said that the amount of glue added to the ordinary copper electrolyte has almost no effect on the determination of the sulfonic acid type anionic surfactant in the copper electrolyte.

5) Influence of glue on wavelength scan measurement of ultraviolet spectrophotometer The methylene blue complex of the sample shown in Table 2 was subjected to wavelength scan measurement in the range of 600 to 700 nm with an ultraviolet spectrophotometer, and the result shown in FIG. 3 was obtained. Obtained.

When 10 times the amount of glue was added, the absorbance was about the same as that of the measurement blank, and it can be said that the influence on the quantitative determination of the sulfonic acid type anionic surfactant was small.
On the other hand, when glue was added 100 times the amount,
At a wavelength of 650 nm or more, the absorbance is about the same level as that of a normal copper electrolyte solution (without addition of glue or the like).
At a wavelength of nm or less, the absorbance increases, and it can be said that the influence on the determination of the sulfonic acid type anionic surfactant is large.

Therefore, it can be said that the amount of glue added to the ordinary copper electrolyte has almost no effect on the determination of the sulfonic acid type anionic surfactant in the copper electrolyte. FIG. 3 also shows the results of wavelength scan measurement of the methylene blue complex in the range of 600 to 700 nm using an ultraviolet spectrophotometer when 60 μg of the sulfonic acid type anionic surfactant was added to the measurement blank. Regarding the peak value of the absorbance, it can be seen that the measurement wavelength in the case of the copper electrolyte alone is close to the measurement wavelength in the case of the sulfonate-type anionic surfactant alone.

[0039]

EXAMPLE As a result of actually quantifying a sulfonic acid type anionic surfactant in a copper electrolyte by the quantification method shown in FIG.
It was found that the content of the sulfonic acid type anionic surfactant in the copper electrolyte was 2.4 ppm.

[0040]

According to the present invention, the accuracy of the determination of the sulfonic acid type anionic surfactant in the copper electrolytic solution is improved, and it is a great clue to investigate the contribution of the sulfonic acid type anionic surfactant in the copper electrolytic solution. .

The present invention can be applied to a plating solution containing a heavy metal.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte according to the present invention.

FIG. 2 is a graph showing the relationship between the absorbance and the amount of a sulfonic acid type anionic surfactant in the method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte according to the present invention.

FIG. 3 is a graph showing the relationship between the absorbance and the wavelength in a wavelength scan measurement of an ultraviolet spectrophotometer used in the method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G042 AA01 BD18 CA10 CB03 DA06 DA08 FA06 FA11 FB02 GA05 HA07 2G054 AA02 CA30 CB01 CE01 CE10 EA04 GB01 4K058 AA10 BA21 BB02 CA09 FC05 FC12 FC19

Claims (4)

[Claims] 1. A method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte or plating solution, comprising the following steps: 1) Heavy metal ions contained in the copper electrolyte or plating solution are complexed with a complexing agent. 2) a process in which a water-soluble sulfonic acid type anionic surfactant contained in the copper electrolyte solution or the plating solution is derivatized into a compound soluble in an organic solvent; Adding a fixed amount of methylene blue, which is an ion pair of the anionic surfactant, to an aqueous solution to generate an aqueous methylene blue solution; 3) bringing the treatment liquid into contact with the aqueous methylene blue solution to form a sulfonic acid-type anionic interface; A step of preparing an aqueous solution in which the methylene blue complex of the activator is dissolved, 4) contacting the aqueous solution in which the methylene blue complex is dissolved with an organic solvent Selectively extracting the methylene blue complex into an organic solvent to produce an extract; 5) measuring the absorbance of the extract; 6) measuring the absorbance with a sulfonic acid type anionic surfactant and the absorbance Determining the amount of the sulfonic acid type anionic surfactant by interpolating the amount of the sulfonic acid type anionic surfactant. 2. The method according to claim 1, wherein the complexing agent is ammonia or ethylenediaminetetraacetic acid. 3. A hydrogen ion concentration range of pH 8 to 1
3. A method according to claim 1 or claim 2, wherein the extract is produced in 2 or less. 4. An interference component other than the methylene blue complex of the sulfonic acid type anionic surfactant is scanned in advance with an ultraviolet spectrophotometer to prevent interference with the measurement wavelength of the methylene blue complex of the sulfonic acid type anionic surfactant. 2. The method according to claim 1, wherein an optimum quantitative wavelength is selected, and absorbance is measured by an ultraviolet spectrophotometer.
A method according to any one of claims 1 to 3.