JPH0340340B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for colorimetric determination of zinc or nickel using a 2-pyridylazoaminophenol derivative represented by the general formula [ ] or a salt thereof as a coloring agent. (In the formula, X and Y are halogen or hydrogen, R ¹ is hydrogen or a lower alkyl group, R ² and R ³ are hydrogen or a lower alkyl group, -(CH ₂ ) _o SO ₃ H (n = 1 to 4 ),

[Formula] represents (l=0-4, m=0-4). ) In recent years, the determination of trace metals has been gaining importance in environmental hygiene and biochemical diagnostic methods. Zinc is a biological trace metal that is widely distributed in living organisms and is one of the essential metal elements necessary for growth. Recently, it has been reported that serum zinc concentration decreases in acrodermatitis, taste disorders, SLE (systemic lupus erythematosus), and zinc deficiency seen during administration of high-calorie infusions. It has become desirable to measure serum zinc levels for observation. On the other hand, nickel is also produced as an ore of its own as Katsura nickelite, but since its chemical properties are similar to iron and copper, it is often mixed in as an impurity in these metals. Most of it is produced with iron and copper. Further, nickel is often used in catalysts and surface treatments, and alloys containing nickel are widely used as corrosion-resistant materials. Therefore, the analysis of nickel in minerals and waste liquids has extremely important meaning in terms of resource development, environmental hygiene, and operational management analysis. To date, methods for quantifying trace metals such as zinc and nickel have mainly relied on atomic absorption spectrometry, flame photometry, and colorimetry, but these methods can process large numbers of samples quickly and do not require special analytical equipment. From this point of view, the colorimetric method is advantageous. Dithizone, zincone, and PAN (1-(2-pyridylazo)-2-naphthol) are mainly used as colorimetric reagents for zinc, and colorimetric methods for nickel include dimethylglyoxime method, diethyldithiocarbamate method, There is a 1-(2-pyridylazo)-2-naphthol (PAN) method, but none of them are necessarily perfect in terms of specificity;
In order to eliminate the interference of copper, cobalt and manganese, it was necessary to use a combination of cyanide compounds and various masking agents, or to extract with organic solvents. On the other hand, the 2-pyridylazoaminophenol derivative or its salt represented by the above general formula [] is a colorimetric reagent developed in recent years that mainly measures zinc and nickel, and has a molecular extinction coefficient of 7.0 to 7.0.
Although it has an extremely high sensitivity of 13.3×10 ⁴ , it often lacks specificity for specific metals, as it is also sensitive to iron, copper, and cobalt, just like conventional colorimetric methods. Therefore, when using these, it is necessary to mask metals other than those for specific purposes as in the past. Commonly used iron masking agents for this purpose are citrate, condensed phosphate, sodium fluoride, nitrilotriacetic acid, 1-hydroxyethane-1,1-
diphosphonic acid, salicylaldoxime as a masking agent for copper, 2-mercaptobenzothiazole, dithiocarboxysarcosine, dithiocarboxyglycine as a masking agent for cobalt, dithiocarboxysarcosine, 2-mercaptobenzothiazole as a masking agent for zinc, glycol ether as a masking agent for zinc. Diaminetetraacetic acid, 1-hydroxyethane-1,1-diphosphonic acid, citric acid, tartaric acid, and condensed phosphoric acid at a pH of 8 or less are used. However, some of these masking agents also mask the target substance, zinc or nickel, resulting in a decrease in sensitivity (for example, citric acid and condensed phosphoric acid for zinc, and 2-mercaptobenzothiazole for nickel). ), and partial structures used as masking agents for copper and cobalt.

[Formula] and -SH group-containing substances have extremely poor stability after preparation, and since they reduce trivalent iron to divalent iron, they may act as color accelerators for iron, which is extremely inconvenient. In order to improve these shortcomings, we conducted extensive research into masking agents that are highly stable and act specifically on specific metals, and as a result of various searches, we found that surfactants are highly effective as masking agents for specific metals. This discovery led to the completion of the present invention. That is, the present invention provides a method for colorimetric determination of zinc or nickel using a 2-pyridylazoaminophenol derivative represented by the general formula [ ] or a salt thereof as a coloring agent, in which one or more surfactants are used as a masking agent. This is a method for colorimetric determination of trace metals, which is characterized by using a chemical agent. The surfactant used in the present invention is not particularly limited, but it is preferably one that dissolves clearly within the optimum pH range of 4 to 10 for the color former. Regarding zinc, nonionic, cationic, or amphoteric surfactants do not inhibit the color development of zinc;
It also suppresses the color development of iron, copper, cobalt, and nickel. Further, similar effects can be obtained when an anionic surfactant and a nonionic surfactant are used together. When these surfactants are used in combination with existing masking agents, their effectiveness is significantly increased. Regarding nickel, when an anionic surfactant is used in combination with existing masking agents for iron, copper, cobalt, and zinc, it does not inhibit the color development of nickel, and can be used to mask iron, copper, and zinc.
Further suppresses color development of copper, cobalt, and zinc. Examples of nonionic surfactants that are particularly effective in the present invention include Triton Product name], Emulgen 120
[Polyoxyethylene lauryl ether, Kao Atlas Co., Ltd. trade name], Tween20 [Polyoxyethylene sorbitan monolauryl ether, Kao Atlas Co., Ltd. trade name], Tween80 [Polyoxyethylene sorbitan monooleyl ether, Kao Atlas Co., Ltd.]
Product name], Softanol 90 [polyoxyethylene alkyl ether, Nippon Shokubai Chemical Co., Ltd.],
TritonX-405 [polyoxyethylene, Rohm & Haas product name], Emulgen 147 [polyoxyethylene lauryl ether, Kao Atlas Co., Ltd. product name],
Emulgen 920 [polyoxyethylene lauryl ether, Kao Atlas Co., Ltd. trade name], Emulgen 950
[Polyoxyethylene nonyl phenyl ether,
Kao Atlas Co., Ltd. trade name], Emulgen PP290N [oxyethylene-oxypropylene block polymer, Kao Atlas Co., Ltd. trade name], Emazol 3130 [polyoxyethylene sorbitan monostearate,
Kao Atlas Co., Ltd. product name] etc. are used, but are not limited to these. As an anionic surfactant, Sandet
EMN [Polyethylene alkyl ether sulfate ester sodium salt, Sanyo Chemical Industries, Ltd. trade name], Emar
NC [polyoxyethylene alkyl phenyl ether sulfate, Kao Atlas Co., Ltd. trade name], alanone ACE [N-cocoyl-N-methyl-β-alanine sodium salt, Kawaken Fine Chemical Co., Ltd. trade name],
Emar 20C [polyoxyethylene alkyl sulfate sodium salt, Kao Atlas Co., Ltd. trade name], Nonipol S-40 [polyethylene alkyl phenyl ether sulfate ester sodium salt, Sanyo Chemical Co., Ltd. trade name], sodium lauryl sulfate [ Lauryl sulfate sodium salt], Sandet BL [alkylbenzenesulfonic acid formalin condensate, Sanyo Chemical Industries, Ltd. trade name], Lebenol WX [polyoxyethylene alkyl sulfate sodium salt, Kao Atlas Co., Ltd. trade name], Ultraphone W [Pentadecylbenzimidazole sulfonic acid sodium salt, Nippon Ciba Geigy Co., Ltd.
Product name], Demol N [naphthalene sulfonic acid formalin condensate, Kao Atlas Co., Ltd. product name], Softanol 30S-25 [secondary alkyl sulfate sodium salt,
Nippon Shokubai Kagaku Kogyo Co., Ltd. trade name], Lebenol WZ [polyoxyethylene alkyl sulfate sodium salt,
Kao Atlas Co., Ltd. product name] etc. are used, but are not limited to these. As a cationic surfactant, Cortamine
24P [Lauryltrimethylammonium chloride,
Kao Atlas Co., Ltd. trade name], Cortamine 86P [stearyltrimethylammonium chloride, Kao Atlas Co., Ltd. trade name], Revathorp NL [laurylpyridinium bromide, Miyoshi Yushi Co., Ltd. trade name], etc. are used, but are limited to these. It is not something that will be done. As an amphoteric surfactant, Amhitol 24B
[Lauryl betaine, trade name of Kao Atlas Co., Ltd.], amphitol 86B [stearyl betaine, trade name of Kao Atlas Co., Ltd.], etc. are used, but are not limited to these. The effective concentration of the surfactant in the present invention is not particularly limited, but is preferably 0.01 to 20.0%. The 2-pyridylazoaminophenol derivative or its salt, which is a coloring agent, has a partial structure has as a chromophore. Representative compounds are 2- represented by the general formula []
Included in pyridylazoaminophenol derivatives or salts thereof. (In the formula, X and Y are halogen or hydrogen, R ¹ is hydrogen or a lower alkyl group, R ² and R ³ are hydrogen or a lower alkyl group, -(CH ₂ ) _o SO ₃ H (n = 1 to 4 ),

[Formula] represents (l=0-4, m=0-4). ) for example, etc. The salts refer to organic amine salts such as diethylamine salts and triethylamine salts, or inorganic salts such as ammonium salts, alkali metal salts, and alkaline earth metal salts. Surfactants are used for the purposes of solubilizing poorly soluble color formers, shifting the absorption wavelength, preventing and clarifying sample turbidity, stabilizing color development, decomposing and liberating target metals, and extracting formed chelates into organic solvents. Although used in colorimetric analysis, the present inventors have discovered that surfactants act as masking agents for metals. That is, the present invention provides a method for colorimetric determination of zinc or nickel using a 2-pyridylazoaminophenol derivative [ ] or a salt thereof as a coloring agent, in which a surfactant acts extremely effectively as a masking agent for a specific metal. This is what I discovered and completed. Examples are given below to further explain the effects of the surfactant of the present invention. Experimental example 1 (1) Coloring reagent 5Br-PAPS (2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol Na salt) 0.05 mmol, sodium citrate 33 g, salicyl Dissolve 1 g of aldoxime and 0.03 mol of borax in water and bring the total amount to 1
and adjust the pH to 9.5 with hydrochloric acid. (2) Sample solution A Dissolve 14 mg of zinc acetate (5 mg as zinc) in water to make a total volume of 100 ml. (3) Sample solution B 48 mg ferric ammonium sulfate (10
mg) in 0.1N HCl to make a total volume of 100 ml. (4) Sample solution C Dissolve 18 mg of copper sulfate (5 mg as copper) in water to make a total volume of 100 ml. (5) Sample solution D Dissolve 11 mg of nickel chloride (5 mg as nickel) in water to make a total volume of 100 ml. (6) Sample solution E Dissolve 11 mg of cobalt chloride (5 mg as cobalt) in water to make a total volume of 100 ml. Experimental method: Add 3 ml of coloring reagent to 20μ of sample solutions A to E, let stand at room temperature for 20 minutes, and then measure the absorbance at 555 nm using a reagent blind control. Table 1 shows the absorbance of each metal and the coloring degree of zinc.
The relative values of each metal are shown, and the relative values of each metal are shown when the degree of color development of nickel is set to 100.

[Table] Experimental example 2 Reagents (1) Color reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, borax
0.03mol, Triton X-100 as surfactant,
Bridge 35, Emulgen 120, Tween 20,
Tween 80, Softanol 90, Emazol
3130, Amhitol 24B, Cortamine 24P, Cortamine 86P, Lebenol WX, Sodium Lauryl Sulfate, or Demol N each alone at 1.6
%, or use a combination of 1% Bridzi-35 and 1% Triton
9.5. (2) Sample solution A Same as Experimental Example 1. (3) Sample solution B Same as Experimental Example 1. (4) Sample solution C Same as Experimental Example 1. (5) Sample solution D Same as Experimental Example 1. (6) Sample solution E Same as Experimental Example 1. Experimental method Add 3 ml of coloring test solution containing each surfactant to 20μ of sample solutions A to E, leave at room temperature for 20 minutes, and then test at 555 nm.
The absorbance of the sample is measured using a reagent blind control. Table 2 shows the color development rate of each metal with respect to the color development of Experimental Example 1, and the relative value of each metal when the color development degree of zinc is set as 100.

【table】

[Table] (The color development rate in the upper row is the color development rate of each metal relative to the color development in Experimental Example 1, and the lower row is the relative value of each metal when the color development degree of zinc is set as 100.) As is clear from Tables 1 and 2, the interface The specificity for zinc is dramatically improved by adding an activator.
In particular, it has excellent color suppression against iron and copper.
This is an extremely important fact in clinical chemistry analysis. Experimental example 3 Reagent (1) Coloring reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, surfactants such as Sandet EMN, Emar NC, Alanone ACE, or Emar 20C 1.6%, borax
Dissolve 0.03mol in water to bring the total amount to 1, and adjust the pH to 9.5 with hydrochloric acid. (2) Sample solution A Same as Experimental Example 1. (3) Sample solution B Same as Experimental Example 1. (4) Sample solution C Same as Experimental Example 1. (5) Sample solution D Same as Experimental Example 1. (6) Sample solution E Same as Experimental Example 1. Experimental method Add 3 ml of coloring test solution containing each surfactant to 20μ of sample solutions A to E, leave at room temperature for 20 minutes, and then test at 555 nm.
The absorbance of the sample is measured using a reagent blind control. Table 3 shows the color development rate of each metal with respect to the color development of Experimental Example 1, and the relative value of each metal when the color development degree of nickel is set as 100.

[Table] (The color development rate in the upper row is the color development rate of each metal relative to the color development in Experimental Example 1, and the lower row is the relative value of each metal when the color development degree of nickel is set as 100.) As is clear from Tables 1 and 3, the interface Addition of an activator dramatically improves the specificity for nickel. Experimental example 4 Reagent (1) Coloring reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, alanone ACE 1.6% or alanone as a surfactant
ACE 0.7% and Buritsuji 351%, Borax 0.03mol
Dissolve in water to bring the total volume to 1, and adjust the pH with hydrochloric acid.
9.5. (2) Sample solution A Same as Experimental Example 1. (3) Sample solution B Same as Experimental Example 1. (4) Sample solution C Same as Experimental Example 1. (5) Sample solution D Same as Experimental Example 1. (6) Sample solution E Same as Experimental Example 1. Experimental method Add 3 ml of coloring test solution containing each surfactant to 20μ of sample solutions A to E, leave at room temperature for 20 minutes, and then test at 555 nm.
The absorbance of the sample is measured using a reagent blind control. Table 4 shows the color development rate of each metal with respect to the color development of Experimental Example 1, and the relative value of each metal when the color development degree of zinc is set as 100.

[Table] (The color development rate in the upper row is the color development rate of each metal relative to the color development in Experimental Example 1, and the lower row is the relative value of each metal when the color development degree of zinc is set as 100.) As is clear from Table 4, the anionic interface When the activator is used alone, the color development of zinc is 0 to 1%, but when a nonionic surfactant is used together, the zinc is unmasked, whereas the cobalt is further masked. As explained above, zinc or nickel can be accurately quantified by appropriately selecting and combining conventionally used masking agents and surfactants from interfering metals expected to coexist in a sample. Examples are shown below. Example 1 Reagent (1) Coloring reagent solution 5Br-PAPS0.05mmol, borax 0.03molBritzy-35 10g was dissolved in water to bring the total amount to 1,
Adjust the pH to 8.5 with hydrochloric acid. (2) Sample solution A sample solution estimated to contain approximately 100μg/d of zinc. Measurement method: Add 3 ml of coloring reagent to 1 ml of sample solution, let stand at room temperature for 5 minutes, then measure absorbance at 555 nm using reagent blind as a control to measure zinc concentration. At this time, as is clear from Tables 1 and 2, the effect of iron is about 1/6 compared to the case of Bridge 35 without additives.
become. Example 2 Reagent (1) Color reagent solution 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, Britsuji 35
20g, Triton
9.5. (2) Sample solution Serum (3) EDTA/4Na salt solution IM Prepare the EDTA/4Na salt solution. Measurement method: Add 2.5ml of coloring reagent to 200μ of sample solution and incubate at room temperature.
After standing for a minute, measure the absorbance at 555 nm. after that
Add 1 drop of EDTA/4Na salt solution to decolorize and leave to stand for 10 minutes, then measure the absorbance at 555 nm using a reagent-blind test to which EDTA has been added as a specimen-blind test. Calculate the concentration of zinc by subtracting the sample-blind absorbance from the absorbance of the sample. At this time, even if iron and copper are present, as is clear from Table 2, they have almost no effect. Example 3 Reagent (1) Coloring reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, emazol
Dissolve 16g of 3130 and 0.03mol of borax in water to make a total volume of 1, and adjust the pH to 9.5 with hydrochloric acid. (2) Sample solution Same as Example 1. Measurement method: Add 3 ml of coloring reagent to 1 ml of sample solution, let stand at room temperature for 5 minutes, then measure the absorbance at 555 nm using a reagent blind control to calculate the zinc concentration. At this time, as is clear from Table 2, even if iron and copper are present, they have almost no effect. Example 4 Reagents (1) Color reagent 5Br-PAPS0.05mmol, salicylaldoxime 1g, alanone ACE 7g, Bridge 35 10g,
Dissolve 0.03 mol of borax in water to bring the total volume to 1, and adjust the pH to 9.5 with hydrochloric acid. (2) Sample solution Same as Example 1. Measurement method: Add 3 ml of coloring reagent to 1.0 ml of sample solution, let stand at room temperature for 5 minutes, then measure absorbance at 555 nm using reagent blind control to calculate zinc concentration. At this time, as is clear from Table 4, there is no interference even if cobalt coexists. Example 5 Reagent (1) Color reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, emal
Dissolve 16g of 20C and 0.03mol of borax in water to make a total volume of 1, and adjust the pH to 9.5 with hydrochloric acid. (2) Sample liquid A sample liquid estimated to contain approximately 100 μg/dl of nickel. Measurement method: Add 3 ml of color reagent to 1 ml of sample solution, let stand at room temperature for 5 minutes, then measure the absorbance at 555 nm using a reagent blind control to calculate the concentration of nickel. At this time, as is clear from Table 3, zinc, copper,
Coexistence of cobalt does not affect nickel measurements. Example 6 Reagent (1) Color reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, lebenol
Dissolve 16g of WX and 0.03mol of borax in water to make a total volume of 1, and adjust the pH to 9.5 with hydrochloric acid. (2) Sample solution Same as Example 1. Measurement method: Add 3 ml of coloring reagent to 1 ml of sample solution, let stand at room temperature for 5 minutes, then measure the absorbance at 555 nm using a reagent blind control to calculate the zinc concentration. At this time, as is clear from Table 2, the presence of iron and copper has almost no effect. Example 7 Reagent (1) Color reagent 5Br-PAPS0.05mmol, sodium citrate
33g, salicylaldoxime 1g, sodium lauryl sulfate 10g, Demol N 10g, borax
Dissolve 0.03mol in water to bring the total amount to 1, and adjust the pH to 9.5 with hydrochloric acid. (2) Sample solution Same as Example 1. Measurement method: Add 3 ml of color reagent to 1 ml of sample solution and leave for 5 minutes.
The absorbance at 555 nm is measured using a reagent blind control, and the concentration of zinc is calculated. At this time, as is clear from Table 2, the presence of iron and copper does not interfere with the measurement.

Claims (1)

[Scope of Claims] 1. One or more masking agents in a method for colorimetric determination of zinc or nickel using a 2-pyridylazoaminophenol derivative represented by the following general formula [] or a salt thereof as a coloring agent. A method for colorimetric determination of trace metals, characterized by using a surfactant. (In the formula, X and Y are halogen or hydrogen, R ¹ is hydrogen or a lower alkyl group, R ² and R ³ are hydrogen or a lower alkyl group, -(CH ₂ ) _o SO ₃ H (n = 1 to 4 ),
[Formula] represents (l=0-4, m=0-4). ) 2 In the colorimetric determination method for zinc using a 2-pyridylazoaminophenol derivative represented by the general formula [ ] or its salt as a coloring agent, existing Fe, Cu,
The colorimetric determination method according to claim 1, which uses a surfactant in addition to the Co and Ni masking agents. 3. Claim 1 in which a nonionic surfactant is used as a surfactant in a method for colorimetric determination of zinc using a 2-pyridylazoaminophenol derivative represented by the general formula [] or a salt thereof as a coloring agent.
The colorimetric determination method described in item 1 or 2. 4 Claim 1 in which a cationic surfactant is used as a surfactant in a method for colorimetric determination of zinc using a 2-pyridylazoaminophenol derivative represented by the general formula [] or a salt thereof as a coloring agent
The colorimetric determination method described in item 1 or 2. 5. Claim 1, in which an amphoteric surfactant is used as a surfactant in a method for colorimetric determination of zinc using a 2-pyridylazoaminophenol derivative represented by the general formula [] or a salt thereof as a coloring agent. Or the colorimetric determination method described in Section 2. 6 In the method for colorimetric determination of zinc using a 2-pyridylazoaminophenol derivative represented by the general formula [] or its salt as a coloring agent, an anionic surfactant and a nonionic surfactant are used together as a surfactant. A method for colorimetric determination according to claim 1 or 2. 7 In the nickel colorimetric determination method using a 2-pyridylazoaminophenol derivative represented by the general formula [] or its salt as a coloring agent, existing Fe, Cu,
The colorimetric determination method according to claim 1, which uses a surfactant in addition to the Co and Zn masking agents. 8 Claim 1 in which an anionic surfactant is used as a surfactant in a method for colorimetric determination of nickel using a 2-pyridylazoaminophenol derivative represented by the general formula [ ] or a salt thereof as a coloring agent The colorimetric determination method described in Section 7 or Section 7.