JP2009036689A - METHOD FOR EASY ANALYSIS OF TRACE AMOUNT OF Se IN ENVIRONMENTAL WATER - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easy analysis of trace amount of Se in environmental water and capable of easily, speedily, and highly accurately determining a trace amount of Se contained in environmental water, such as, clean water, various types of drainages, underground water, river water, and water eluted from soil. <P>SOLUTION: The method for easily analyzing a trace amount of Se in environmental water includes a process for diluting environmental water by pure water twenty times or more; the process for adjusting the pH of the environmental water, after the dilution; the process for adding 2,3-diaminonaphthalene (hereinafter, to be referred to as DAN) to the environmental water, after the pH adjustment; the process for forming an Se complex of DAN by heating the environmental water after the addition of DAN; the process for extracting the Se complex of DAN by an organic solvent; and the process for determining extracted Se of the Se complex of DAN in the organic solvent by using a fluorometer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a simple analysis method for trace amounts of Se (selenium) contained in environmental water such as clean water, various wastewaters, ground water, river water, and soil elution water.

  For environmental water such as tap water, tap water, various wastewater, groundwater, river water, and soil elution water, the concentration of various solute elements is defined based on water quality standards related to human health.

Se is one of them, and various methods such as 3,3-diaminobenzidine absorptiometry, hydride generation atomic absorption method and hydride generation ICP emission spectroscopy as defined in JIS K 0102 The quantification is performed by an electrochemical measurement method such as a voltammetry method described in Patent Document 1.
T. Ishiyama and T. Tanaka; Anal. Chem., 68 (1996) 3789

  However, 3,3-diaminobenzidine absorptiometry is a relatively simple method, but its analytical sensitivity is low and unsuitable for analysis of trace concentrations, and hydride generation atomic absorption or hydride generation ICP emission spectroscopy. The analytical method has high analytical sensitivity and is suitable for analyzing trace concentrations, but requires not only large incidental facilities such as gas pipes and exhaust ducts but also complicated sample pretreatment operations. In addition, the voltammetry method is a simple and rapid analysis method, but it requires extremely complicated maintenance of the working electrode surface and sample preparation before measurement, so that the reproducibility is inferior and high analysis accuracy is not always obtained.

  The present invention provides a simple method for analyzing trace amounts of Se in environmental water that can be quantified easily and quickly with high accuracy in trace amounts of Se contained in environmental water such as tap water, various effluents, ground water, river water, and soil elution water. For the purpose.

  The purpose of this is to dilute environmental water 20 times or more with pure water, adjust the pH of the diluted environmental water, and add 2,3-diaminonaphthalene (hereinafter, Adding the DAN), heating the environmental water after the DAN addition to form a DAN Se complex, extracting the DAN Se complex with an organic solvent, and the DAN Se This is achieved by a simple analysis method for trace amounts of Se in environmental water having a step of quantifying Se in an organic solvent from which a complex has been extracted by a standard addition method using a fluorometer.

  According to the present invention, trace amounts of Se contained in environmental water such as clean water, various waste waters, ground water, river water, and soil elution water can be quantified simply and quickly with high accuracy. In other words, complicated sample pretreatment and large-scale incidental facilities are not required, and trace Se can be quantified with high accuracy in about 30 minutes. In addition, since all the operations can be performed in one test tube, there are also advantages such as being very simple, using a small amount of reagent, and measuring with higher accuracy without contamination during operation and reduction of samples.

  Environmental water such as clean water, various effluents, ground water, river water, and soil elution water, which is the subject of the analysis method of the present invention, is collected as an analysis sample in accordance with the JIS K 0102 method or the Notification No. 46 method. .

  The environmental water is collected in a plurality of test tubes by the above method, and the environmental water collected in each test tube is diluted 20 times or more with pure water. This is to avoid the influence of other elements coexisting in the environmental water. However, if the dilution rate is too large, the amount of the sample increases, the operation becomes complicated, and the sensitivity of the subsequent fluorometric measurement is reduced. Therefore, it is preferable to dilute 30 to 50 times.

  A Se standard solution with a known concentration is added stepwise to the diluted test tube to prepare a sample for the standard addition method. The addition amount of the Se standard solution is preferably in the range of 5 to 30 ng in terms of Se amount, and it is preferable to prepare a sample that has been changed to at least two stages, preferably three stages such as 10, 20, and 30 ng.

  Separately from this, a test tube containing only the same amount of pure water and not containing environmental water or Se standard solution is prepared as a control sample. This control sample is used as a reagent blank for zero point correction.

  Adjust pH by adding hydrochloric acid to a test tube to which Se standard solution is added stepwise and a test tube containing pure water only. At this time, it is preferable to adjust the pH to 1.0 to 1.5.

  A certain amount of DAN is added to all the pH-adjusted test tubes and heated to form a DAN Se complex. At this time, in order to form a DAN Se complex, it is preferable to heat at 50 ° C. for about 20 minutes.

  For example, add 3 ml or more of an organic solvent such as cyclohexane or toluene to all test tubes in which the DAN Se complex is formed, and extract the DAN Se complex by solvent. At this time, if the amount of the organic solvent added is too small, the concentration rate becomes high, but it becomes inconvenient because it is difficult to secure a sufficient amount of the organic solvent to fill the fluorescent cell for the measurement of the fluorescence. When using a fluorimeter using a flow cell, about 3 ml can be measured sufficiently.

  The organic solvent from which the DAN Se complex is extracted floats at the top of the test tube. For example, when cyclohexane is used as the organic solvent, the excitation wavelength is 375 nm and the fluorescence wavelength is 520 nm. Measure and obtain the amount of Se in the water to be analyzed by the standard addition method, that is, from the relationship between the amount of Se when the amount of Se is added stepwise and the fluorescence intensity. The excitation wavelength and the fluorescence wavelength are appropriately selected depending on the organic solvent used.

  Elution water A, B, C, and D were collected from each of the four types of inorganic materials for civil engineering materials according to the Notification No. 46 method in three test tubes. Purified water, Se standard solution, and hydrochloric acid are added sequentially to three test tubes of each elution water, and three types of samples with a total volume of 30 ml, pH of 1.0 to 1.5, and Se addition amounts of 0, 10, and 20 ng are added. Created. Separately, a test tube containing only 30 ml of pure water having a pH of 1.0 to 1.5 and hydrochloric acid was prepared as a control sample.

  5 ml of 0.2% DAN solution adjusted with 0.1M hydrochloric acid was added to all the test tubes prepared in this way, and then heated in an aluminum block bath at 50 ° C. for 20 minutes to form a DAN Se complex.

  After allowing to cool, 3 ml of cyclohexane was added, and the Se complex of DAN was extracted with a solvent.

  Inject the floating organic solvent into the fluorometer, measure the luminous intensity at the excitation wavelength of 375 nm and the fluorescence wavelength of 520 nm, by the standard addition method, that is, FIG. 1 (a), (b), (c), (d) The amount of Se in elution water A, B, C, and D was quantified from the point where the straight line intersects the horizontal axis.

  The results are shown in Table 1 together with the amount of Se separately determined by hydride generation atomic absorption.

  The amount of Se determined by the method of the present invention is almost the same as the amount of Se determined by the hydride generation atomic absorption method, and the analysis time is as short as about 45 minutes. It can be seen that it is a simple, rapid and highly accurate method for quantifying trace Se contained in environmental water such as river water and soil elution water.

It is a figure which shows the fixed_quantity | quantitative_assay result by the standard addition method used by this invention.

Claims (1)

A step of diluting environmental water with pure water 20 times or more,
Adjusting the pH of the environmental water after dilution;
Adding 2,3-diaminonaphthalene (hereinafter referred to as DAN) to the environmental water after pH adjustment;
Heating the environmental water after the addition of DAN to form a DAN Se complex;
Extracting the Se complex of DAN with an organic solvent;
Se in the organic solvent from which the Se complex of DAN has been extracted is quantified by a standard addition method using a fluorometer,
A simple method for analyzing trace amounts of Se in environmental water.

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