CN106370610A - Method of detecting content of trace phenol in nitro-o-xylene - Google Patents

Abstract

The invention discloses a method of detecting the content of trace phenol in nitro-o-xylene; the content of nitrophenol by weight in nitro-o-xylene is measured by means of spectrophotometry. The method has good accuracy and repeatability and is simple to perform.

Description

The detection method of micro-phenol content in a kind of nitro o-Dimethylbenzene

Technical field

The invention belongs to field of chemical detection and in particular in nitro o-Dimethylbenzene micro-phenol content detection method.

Background technology

Nitro o-Dimethylbenzene is high energy material and the important intermediate of high-grade organic dyestuff, is also that chemical synthesiss produce dimension The important source material of raw element b2, is important medicine intermediate.Through practice, the content of ortho-nitrophenol in nitro o-Dimethylbenzene, can make Reference index for nitro o-Dimethylbenzene end product quality.

Generally adopt the phenol content in high effective liquid chromatography for measuring nitro o-Dimethylbenzene production process, this detection method because Accuracy is high and be widely adopted.But when the content of phenol in nitro o-Dimethylbenzene finished product is detected using the method, testing result Accuracy can be impacted.

Content of the invention

Not enough for prior art, it is an object of the invention to provide micro-phenol mass fraction in a kind of nitro o-Dimethylbenzene Detection method.It is high, the features such as simple to operate that the method has accuracy of detection.

The present invention seeks to be achieved through the following technical solutions:

In nitro o-Dimethylbenzene of the present invention, the detection method of the content of micro-phenol is it is characterised in that include following walking Rapid:

S1. prepare standard coloration liquid；

S2. bioassay standard nitrite ion absorbance, obtains standard value, draws standard working curve；

S3. prepare sample solution；

S4. measure sample solution absorbance, carried out with described standard working curve by the result of spectrophotometry Contrast, draws nitrophenols content.

Preferably, in described nitro o-Dimethylbenzene, the detection method of micro-phenol content comprises the following steps:

S1. the preparation of standard coloration liquid: pipette 50ml 0.2mg/ml ortho-nitrophenol standard solution in 250ml volumetric flask, And add 125ml 0.05mol/l potassium hydroxide solution, make colour developing；With distilled water diluting to groove, extract and separate；Carved with 25ml Degree pipet pipettes each two parts of 5.0ml, 7.5ml, 10ml, 12.5ml, 15ml, 17.5ml aqueous phase solution, is respectively placed in 50ml and holds In measuring bottle, with distilled water diluting to groove；

S2. the mensure of standard coloration liquid absorbance: use 1cm cuvette, mensure wavelength is 440nm, is reference with distilled water, The absorbance of bioassay standard chromophoric solution, with absorbance as vertical coordinate, draws standard curve with the quality of nitrophenols for abscissa；

S3. the preparation of sample solution: accurately weigh 20.0g nitro o-Dimethylbenzene sample, be cooled to room temperature after melting, add 20ml toluene, after heating in water bath dissolving, transfers in 100ml volumetric flask, with dilution with toluene to groove, shakes up, obtain nitro neighbour two Toluene sample solution；

125ml potassium hydroxide solution, 45ml nitro o-Dimethylbenzene sample solution is accurately added successively, gently in separatory funnel Vibration, pours aqueous phase in 250ml beaker into after aqueous phase clarification, takes two parts of this solution of 45ml with pipet, move to 50ml respectively In volumetric flask, obtain solution 1 and solution 2；

Solution 1 is acidified with hydrochloric acid, until the yellow of solution disappears, then Deca 1-2d hydrochloric acid, extremely with distilled water diluting finally Groove, shakes up；

Solution 2 distilled water diluting, to groove, shakes up.

S4. the mensure of sample solution absorbance: use 1cm cuvette, mensure wavelength is 440nm, with solution 1 acidifying solution for ginseng Ratio measures the absorbance of nitro o-Dimethylbenzene sample；

It is right that the absorbance detection result of gained nitro o-Dimethylbenzene sample and step s2 gained standard working curve are carried out Ratio calculates nitrophenols content in nitro o-Dimethylbenzene.

Preferably,

Described in step s1, the compound method of ortho-nitrophenol standard solution is: accurately weighs 100.0mg ortho-nitrophenol, puts into In 50ml beaker, add 20ml～30ml toluene, water-bath slight fever makes dissolving, quantitatively proceeds in 500ml volumetric flask, use dilution with toluene To scale.

Toluene of the present invention is that analysis is pure；

Preferably, described concentration of hydrochloric acid is 6mol/l.

Described nitrophenols content is:

The mass fraction of nitrophenols represents, numerical value is represented with % with ω 1, calculates by formula (1):

${\mathrm{\ω}}_1=\frac{m_1}{m\×\frac{45}{100}\×\frac{45}{125}\×1000}\×100\%---\left(1\right)$

In formula:

M1, according to the absorbance of the sample solution recording, checks in the quality of nitrophenols from described working curve, single Position is mg；

The quality of m sample solution, unit is g.

The detection method of the present invention has accuracy in detection height, easy-operating beneficial effect.

Brief description

Fig. 1 is the standard curve of ortho-nitrophenol.

Specific embodiment

The present invention is explained in greater detail below with reference to embodiment, embodiments of the invention are merely to illustrate the skill of the present invention Art scheme, and non-limiting the spirit and scope of the invention.

Embodiment 1

The detection method of micro-phenol content in nitro o-Dimethylbenzene of the present invention, operating procedure is as follows:

(1) preparation of standard coloration liquid: pipette 50ml 0.2mg/ml ortho-nitrophenol standard solution in 250ml volumetric flask, And add 125ml 0.05mol/l potassium hydroxide solution, make colour developing；With distilled water diluting to groove, extract and separate；Carved with 25ml Degree pipet pipettes each two parts of 5.0ml, 7.5ml, 10ml, 12.5ml, 15ml, 17.5ml aqueous phase solution, is respectively placed in 50ml and holds In measuring bottle, with distilled water diluting to groove；

Wherein, the compound method of ortho-nitrophenol standard solution is: accurately weighs 100.0mg ortho-nitrophenol, puts into 50ml and burn In cup, add 20ml～30ml toluene, water-bath slight fever makes dissolving, quantitatively proceeds in 500ml volumetric flask, with dilution with toluene to quarter Degree.

(2) mensure of standard coloration liquid absorbance: use 1cm cuvette, mensure wavelength is 440nm, is reference with distilled water, The absorbance of bioassay standard chromophoric solution, with absorbance as vertical coordinate, draws standard with the quality of ortho-nitrophenol for abscissa bent Line, as shown in Figure 1；

(3) preparation of sample solution: accurately weigh 20.0g nitro o-Dimethylbenzene sample, be cooled to room temperature after melting, add 20ml toluene, after heating in water bath dissolving, transfers in 100ml volumetric flask, with dilution with toluene to groove, shakes up, obtain nitro neighbour two Toluene sample solution；

125ml potassium hydroxide solution, 45ml nitro o-Dimethylbenzene sample solution is accurately added successively, gently in separatory funnel Vibration, pours aqueous phase in 250ml beaker into after aqueous phase clarification, takes two parts of this solution of 45ml with pipet, move to 50ml respectively In volumetric flask, obtain solution 1 and solution 2；

Solution 1 uses 6mol/l hydrochloric acid to be acidified, until the yellow of solution disappears, then Deca 1-2d 6mol/l hydrochloric acid, finally use Distilled water diluting, to groove, shakes up；

Solution 2 distilled water diluting, to groove, shakes up；

(4) mensure of sample solution absorbance: use 1cm cuvette, mensure wavelength is 440nm, with solution 1 acidifying solution for ginseng Ratio measures the absorbance of nitro o-Dimethylbenzene sample.

Embodiment 2-6

With reference to the detection method of embodiment 1, select the nitro o-Dimethylbenzene finished product of 5 different production batch, measure not same The absorbance of product, obtains embodiment 2-6, as shown in table 1 by calculating nitro content:

Nitrophenols content in table 1 nitro o-Dimethylbenzene finished product

Claims (5)

1. in a kind of nitro o-Dimethylbenzene the detection method of micro-phenol content it is characterised in that comprising the following steps:

S1. prepare standard coloration liquid；

S2. bioassay standard nitrite ion absorbance, obtains standard value, draws standard working curve；

S3. prepare sample solution；

S4. measure sample solution absorbance, contrasted with described standard working curve by the result of spectrophotometry, Draw nitrophenols content.

2. in nitro o-Dimethylbenzene according to claim 1 micro-phenol content detection method it is characterised in that include with Lower step:

S1. the preparation of standard coloration liquid: pipette 50ml 0.2mg/ml ortho-nitrophenol standard solution in 250ml volumetric flask, and plus Enter 125ml 0.05mol/l potassium hydroxide solution, make colour developing；With distilled water diluting to groove, extract and separate；Moved with 25ml scale Liquid pipe pipettes each two parts of 5.0ml, 7.5ml, 10ml, 12.5ml, 15ml, 17.5ml aqueous phase solution, is respectively placed in 50ml volumetric flask In, with distilled water diluting to groove；

S2. the mensure of standard coloration liquid absorbance: use 1cm cuvette, mensure wavelength is 440nm, is reference with distilled water, measure The absorbance of standard coloration solution, with absorbance as vertical coordinate, draws standard curve with the quality of ortho-nitrophenol for abscissa；

S3. the preparation of sample solution: accurately weigh 20.0g nitro o-Dimethylbenzene sample, be cooled to room temperature after melting, add 20ml Toluene, after heating in water bath dissolving, transfers in 100ml volumetric flask, with dilution with toluene to groove, shakes up, obtain nitro o-Dimethylbenzene Sample solution；

Accurately add 125ml potassium hydroxide solution, 45ml nitro o-Dimethylbenzene sample solution successively in separatory funnel, gently shake Swing, pour aqueous phase in 250ml beaker into after aqueous phase clarification, take two parts of this solution of 45ml with pipet, move to 50ml respectively and hold In measuring bottle, obtain solution 1 and solution 2；

Solution 1 is acidified with hydrochloric acid, until the yellow of solution disappears, then Deca 1-2d hydrochloric acid, finally with distilled water diluting to groove, Shake up；

Solution 2 distilled water diluting, to groove, shakes up；

S4. the mensure of sample solution absorbance: use 1cm cuvette, mensure wavelength is 440nm, with solution 1 acidifying solution as reference, Measure the absorbance of nitro o-Dimethylbenzene sample；

The absorbance detection result of gained nitro o-Dimethylbenzene sample and step s2 gained standard working curve are contrasted, meter Calculation draws nitrophenols content in nitro o-Dimethylbenzene.

3. in nitro o-Dimethylbenzene according to claim 2 the detection method of micro-phenol content it is characterised in that step s1 The compound method of described ortho-nitrophenol standard solution is: accurately weighs 100.0mg ortho-nitrophenol, puts in 50ml beaker, adds 20ml～30ml toluene, water-bath slight fever makes dissolving, quantitatively proceeds in 500ml volumetric flask, with dilution with toluene to scale.

4. in nitro o-Dimethylbenzene according to claim 2 the detection method of micro-phenol content it is characterised in that described salt Acid concentration is 6mol/l.

5. in nitro o-Dimethylbenzene according to claim 2 the detection method of micro-phenol content it is characterised in that described nitre Base phenol content is:

The mass fraction of nitrophenols represents, numerical value is represented with % with ω 1, calculates by formula (1):

${\mathrm{\ω}}_1=\frac{m_1}{m\×\frac{45}{100}\×\frac{45}{125}\×1000}\×100\%---\left(1\right)$

In formula:

M1, according to the absorbance of the sample solution recording, checks in the quality of nitrophenols from described standard curve, and unit is mg；

The quality of m sample solution, unit is g.