CN101329269A

CN101329269A - Method for determining concentration of single ingredient water solution with known solute

Info

Publication number: CN101329269A
Application number: CNA2008100226163A
Authority: CN
Inventors: 刘明春
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-07-16
Filing date: 2008-07-16
Publication date: 2008-12-24

Abstract

The invention discloses a consistency determination method of single composition water solution with known solvent, comprising the steps of: a. searching the wavelength with maximum ultraviolet absorptivity of the known solvent in the solution to be detected; subsequently, choosing an ultraviolet visible light spectrophotometer of a suitable type according to the wavelength; b. precisely compounding three or more parts of water solution of the known solvent in the solution to be detected with different consistency; c. measuring the ultraviolet absorptivity of the solution compounded in the step b at the wavelength position known in the step a by using the ultraviolet visible light spectrophotometer chosen in the step a; d. establishing a standard curve and fitting the calculation formula by origin software for solution consistency compounded in the step b and the ultraviolet adsorptivity measured in the step c; e. measuring the adsorptivity of the solution to be detected at the wavelength position known in the step a by using the ultraviolet visible light spectrophotometer chosen in the step a; f. substituting the adsorptivity measured in the step e into the calculation formula fit in the step d and calculating the consistency of the solution to be detected.

Description

The method for measurement of concentration of the one-component aqueous solution that solute is known

Technical field

The invention discloses the method for measurement of concentration of the known one-component aqueous solution of a kind of solute, belong to the quantitative test field.

Background technology

Traditional solution concentration assay method is to add thermal crystalline, uses balance to weigh after the quality of solution and crystal, draws the concentration of solution according to solution quality on the solute mass ratio.This method is simple, but method own is subjected to the restriction of solute physical characteristics.For volatile, fusing point is low, low-boiling material, heating-up temperature is too high, cause solute volatilization or chemical change take place, be to measure to carry out; For the very low material of solubleness own, measuring error is bigger, some in addition can't carry out.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, the method for measurement of concentration of the one-component aqueous solution that the solute of provide that a kind of method of operating is easy, quick, favorable reproducibility, analysis time are short is known, this method not only applicable to volatile, fusing point is low, the solution concentration of low-boiling material is measured but also applicable to the solution concentration mensuration of difficulty volatilization, fusing point height, material that boiling point is high.

According to technical scheme provided by the invention, the method for measurement of concentration of the one-component aqueous solution that described solute is known comprises following steps:

A, search in the solution to be measured known to the wavelength of ultraviolet light maximum absorbance of solute, select the ultra-violet and visible spectrophotometer of suitable types then according to this wavelength;

B, accurately prepare in the solution to be measured known to the different aqueous solution of concentration more than 3 parts or 3 parts of solute;

The uv absorption rate (Abs) of ultra-violet and visible spectrophotometer determination step b institute obtain solution wavelength location known to step a that c, usefulness step a select;

D, the measured uv absorption rate (Abs) of solution concentration, step c that step b is prepared use the origin software of U.S. OriginLab company (its predecessor is Microcal company) exploitation to set up typical curve and simulate computing formula;

E, the ultra-violet and visible spectrophotometer of selecting with step a are measured the absorptivity of solution to be measured wavelength location known to step a;

In the computing formula that f, the absorptivity substitution steps d that step e is measured are simulated, calculate the concentration of solution to be measured.

Wherein, step b accurately in the preparation solution to be measured known to the aqueous solution of solute be 3～7 parts.

The concrete measurement procedure of step e is as follows: open ultraviolet-visible pectrophotometer, measurement pattern is adjusted to absorptiometry, and wavelength is adjusted to correct position, stablizes 15～20min; Prepare two quartz sample pools, dry up standby after the cleaning; Two sample cells are respectively charged into distilled water and testing sample, and spectrophotometer test cabinet relevant position is put in capping; Use distilled water and black matrix calibration spectrophotometer; Adjust the sample cell position, read corresponding absorptivity.

Characteristics such as that method of the present invention has is easy and simple to handle, quick, favorable reproducibility, analysis time are short, and this method not only applicable to volatile, fusing point is low, the solution concentration of low-boiling material is measured but also applicable to the solution concentration mensuration of difficulty volatilization, fusing point height, material that boiling point is high.

Description of drawings

Fig. 1 is the curve map of embodiment 1.

Fig. 2 is the curve map of embodiment 2.

Fig. 3 is the curve map of embodiment 3.

Embodiment

The invention will be further described below in conjunction with concrete drawings and Examples.

Embodiment 1

Measure the concentration of aqueous solution of triethylenediamine

1, triethylenediamine absorptivity when the 280nm of ultraviolet light wavelength is the highest, has therefore selected the ultraviolet-visible pectrophotometer of 260～460nm wave band.Open ultraviolet-visible pectrophotometer, measurement pattern is adjusted to absorptivity and measures, and ultraviolet wavelength is adjusted to 280nm, and stablizes 15～20min.

2, use the accurate weighing triethylenediamine of electronic balance, the configuration quality percent concentration is respectively 5 kinds of solution of 4.25%, 5.25%, 6.25%, 7.25%, 8.25%.

3, prepare 6 quartz sample pools, clean up with distilled water, and be dried with air-blow drying machine.

4, in 6 sample cells, be respectively charged into distilled water and testing sample and sealing, insert spectrophotometer test cabinet relevant position.

5, adjust the sample cell gear, use distillation pond and black matrix pond calibration ultraviolet spectrophotometer respectively.

6, adjust the sample cell gear to the testing sample pond, read absorptivity (Abs).(test result sees Table 1)

7, handle above operation by application software origin and draw data, draw corresponding curve map (Fig. 1) and fitting formula automatically, and to formula as suitable simplification, thereby draw:

The expression formula of triethylene diamino concentration of aqueous solution is: C%=1.320+32.0 * Abs;

8, in the UV Absorption rate score substitution expression formula " C%=1.320+32.0 * Abs " with table 1 gained, obtain corresponding calculating solubility, calculating concentration and the actual concentrations that obtains contrasted to verify the rationality of this expression formula, result's contrast sees Table 2.

Table 1

Solution concentration (%)	4.25	5.25	6.25	7.25	8.25
Solution concentration (%)	4.25	5.25	6.25	7.25	8.25	Uv absorption rate	0.0932	0.1234	0.1553	0.1921	0.2162

Table 2

The comparative illustration match of calculating concentration and actual concentrations from table 2 very near actual conditions.

Embodiment 2

Measure the concentration of aqueous solution of formaldehyde

1, formaldehyde absorptivity when the 412nm of ultraviolet light wavelength is the highest, has therefore selected the ultraviolet-visible pectrophotometer of 260～460nm wave band.Open ultraviolet-visible pectrophotometer, measurement pattern is adjusted to absorptivity and measures, and ultraviolet wavelength is adjusted to 412nm, and stablizes 15～20min.

2, use the accurate weighing formaldehyde of electronic balance, configuration concentration is respectively 5 kinds of solution of 3.00mg/Kg, 4.00mg/Kg, 5.00mg/Kg, 6.00mg/Kg, 7.00mg/Kg.

6, adjust the sample cell gear to the testing sample pond, read absorptivity (Abs).(test result sees Table 3)

7, handle above operation by application software origin and draw data, draw corresponding curve map (Fig. 2) and fitting formula automatically, and to formula as suitable simplification, thereby draw:

Formalin concentration C mg/Kg=0.025+23.135Abs;

8, with the UV Absorption rate score substitution expression formula of table 3 gained: among the C mg/Kg=0.025+23.135Abs, obtain corresponding calculating solubility, to verify the rationality of this expression formula, the result contrasts and sees Table 4 with the calculating concentration that obtains and actual concentrations contrast.

Table 3

Solution concentration (%)	3	4	5	6	7
Solution concentration (%)	3	4	5	6	7	Uv absorption rate	0.1292	0.1725	0.2160	0.2587	0.3018

Table 4

The comparative illustration match of calculating concentration and actual concentrations from table 4 very near actual conditions.

Embodiment 3

Measure C ₆₀The concentration of aqueous solution:

1, C ₆₀Absorptivity is the highest when the 274nm of ultraviolet light wavelength, has therefore selected the ultraviolet-visible pectrophotometer of 260～460nm wave band.Open ultraviolet-visible pectrophotometer, measurement pattern is adjusted to absorptivity and measures, and ultraviolet wavelength is adjusted to 412nm, and stablizes 15～20min.

2, measure 0.500ml, 0.600ml, 0.700ml, 0.800ml, 0.900ml C ₆₀Aqueous solution after, add the 1.000ml distilled water diluting respectively, obtain the dilute aqueous solution of 5 parts of different relative concentrations.

6, adjust the sample cell gear to the testing sample pond, read absorptivity (Abs).(test result sees Table 5).

7, handle above operation by application software origin and draw data, draw corresponding curve map (Fig. 3) and fitting formula automatically, and to formula as suitable simplification, thereby draw:

C ₆₀The relative concentration C=-0.013+1.299Abs of aqueous solution;

8, with the UV Absorption rate score substitution expression formula of table 5 gained: among the C=-0.013+1.299Abs, obtain corresponding calculating solubility, to verify the rationality of this expression formula, the result contrasts and sees Table 6 with the calculating concentration that obtains and the contrast of actual relative concentration.

Table 5

Actual relative concentration	0.5	0.6	0.7	0.8	0.9
Actual relative concentration	0.5	0.6	0.7	0.8	0.9	Uv absorption rate	0.3951	0.4756	0.5512	0.6261	0.7063

Table 6

Actual relative concentration	Calculating concentration	Error
Actual relative concentration	Calculating concentration	Error	0.500	0.500	0.000
0.600	0.604	0.004	0.500	0.500	0.000
0.600	0.604	0.004	0.700	0.703	0.003
0.800	0.800	0.000	0.700	0.703	0.003
0.800	0.800	0.000	0.900	0.904	0.004

The comparative illustration match of calculating concentration and actual relative concentration from table 6 very near actual conditions.

Claims

The method for measurement of concentration of the one-component aqueous solution that 1, a kind of solute is known is characterized in that this method comprises following steps:

A, search in the solution to be measured known to the wavelength of ultraviolet light maximum absorbance of solute, select the ultra-violet and visible spectrophotometer of suitable types then according to this wavelength;

B, accurately prepare in the solution to be measured known to the different aqueous solution of concentration more than 3 parts or 3 parts of solute;

The uv absorption rate (Abs) of ultra-violet and visible spectrophotometer determination step b institute obtain solution wavelength location known to step a that c, usefulness step a select;

D, the measured uv absorption rate (Abs) of solution concentration, step c that step b is prepared use software origin to set up typical curve and simulate computing formula;

E, the ultra-violet and visible spectrophotometer of selecting with step a are measured the absorptivity of solution to be measured wavelength location known to step a;

In the computing formula that f, the absorptivity substitution steps d that step e is measured are simulated, calculate the concentration of solution to be measured.
The method for measurement of concentration of the one-component aqueous solution that 2, solute as claimed in claim 1 is known is characterized in that: step b accurately in the preparation solution to be measured known to the aqueous solution of solute be 3～7 parts.