CN110082469B - Method for measuring content of trace alcohols and ketones in transformer insulating oil - Google Patents
Method for measuring content of trace alcohols and ketones in transformer insulating oil Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/88—Integrated analysis systems specially adapted therefor, not covered by a single one of the groups G01N30/04 - G01N30/86
Abstract
The invention provides a method for measuring the contents of trace alcohols and ketones in transformer insulating oil, which comprises the following steps: adding standard solutions of alcohols and/or ketones to be detected into transformer insulating oil to be detected by adopting a standard adding method, and preparing a series of standard samples with different adding concentrations; separating and detecting by adopting a headspace sample injection method by using a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combined method, and obtaining the chromatogram peak area of the alcohols and/or ketones to be detected corresponding to the standard sample; and establishing a standard curve according to the peak area of the chromatogram and the added concentration in the standard sample, fitting to obtain a linear equation, and calculating the content of the alcohol and/or ketone substances to be detected in the base solution according to the linear equation. The measuring method can realize the test of various alcohols and/or ketones by single sample injection; and repeatability and stability are good, measurement accuracy is improved, and measurement range is enlarged.
Description
Technical Field
The invention relates to the technical field of high-voltage insulation, in particular to a method for measuring the content of trace alcohols and ketones in transformer insulating oil.
Background
The aging evaluation of cellulose insulation in transformers is usually performed by indirectly measuring chemical markers in the insulating oil. Furan compounds were first identified as an indicator of paper aging in the beginning of the 80 s of the 20 th century. Among them, 2-furaldehyde (2-FAL) is widely used because of its high concentration in oil and good stability. However, detection of furan compounds, i.e. furfural, also has a number of drawbacks, such as absorption by insulating paper, chemical instability, etc.
Methanol has been proposed as a paper aging indicator in a short history compared to furans. Methanol was first proposed as an indicator of paper aging around 2007. Thirty or more products of the aging of the insulating paper are separated and detected by adopting a headspace gas chromatography-mass spectrometry method, and a comparison test and a stability test are carried out on the products, so that methanol is initially determined as a characterization object for representing the aging degree of the insulating paper. A new thought and method are provided for effectively measuring the methanol content in the insulating paper by Pierre T process and the like, and the sensitivity and stability of methanol as a characteristic product are further researched. Gilbert et al studied the effect of plain insulating paper and thermally modified insulating paper on methanol production and proposed that methanol production was directly linked to cellulose cleavage of insulating paper, and experiments showed that methanol was mainly produced from cellulose, but not from cellulose such as dextran or glucose, and that methanol production and decomposition of the 1,4-b glycosidic bond linking the glucose units of cellulose were significantly related, so that methanol was detected earlier than furfural. Foreign scholars find that methanol is more sensitive than furfural in the early stage of paper aging through an accelerated laboratory aging experiment, so that methanol is recommended to be used as a characterization object in the early stage of paper aging, and at present, the method is also used at home and abroad, only methanol is used as a single characterization object, and other alcohol substances except methanol are studied freshly.
In addition, the existing method for measuring the methanol in the insulating oil generally adopts a standard curve quantification method, a series of standard samples are prepared by adopting a blank sample matrix, a standard curve is established, and then the content of a sample to be measured is measured by adopting the standard curve. As in patent document CN106706821a, chromatographically pure methanol is added to a blank insulating oil, which is a standard insulating oil used for transformers. Due to the influence of factors such as difference of standard insulating oil, the condition that the methanol is used as a single characteristic parameter at present has no engineering application in the aspects of stability and repeatability.
The present invention therefore proposes to improve the existing measurement systems and to study other alcohols including methanol, such as: ethanol, propanol (n-propanol and isopropanol), butanol, etc.; and the ketone substances are also used as characteristic parameters for testing, so that the measurement range is enlarged, the measurement accuracy is improved, and a richer detection means and data basis are provided for the aging evaluation of the oil paper insulation.
Disclosure of Invention
In view of the above, the invention provides a method for measuring the content of trace alcohols and ketones in transformer insulating oil, which is used for engineering, and aims to solve the existing problems, and the method is better in repeatability and stability aiming at the current situation of ageing evaluation of cellulose insulating materials in the existing transformer.
The invention provides a method for measuring the contents of trace alcohols and ketones in transformer insulating oil, which comprises the following steps:
the method comprises the steps of obtaining transformer insulating oil to be detected as a base solution, adding standard solutions of alcohols and/or ketones to be detected into the base solution, and preparing a series of standard samples with different addition concentrations;
extracting volatile substance gases corresponding to the standard sample by adopting a headspace sampling method, and separating and detecting alcohols and/or ketones to be detected in the volatile substance gases by using a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combination method to obtain the chromatogram peak areas of the alcohols and/or ketones to be detected corresponding to the standard sample;
and establishing a standard curve according to the peak area of the chromatogram and the added concentration in the standard sample, fitting to obtain a linear equation, and calculating the content of the alcohol and/or ketone substances to be detected in the base solution according to the linear equation.
Further, the method for measuring the trace alcohol and ketone substance content in the transformer insulating oil further comprises the steps of obtaining the corresponding chromatogram peak areas of the alcohol and/or ketone substance to be detected in other similar transformer insulating oil to be detected by adopting a headspace sampling method and using a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combination method, and obtaining the content of the alcohol and/or ketone substance to be detected according to a linear equation obtained by fitting.
Further, the equilibrium temperature of the headspace sampling method is 60-90 ℃ and the equilibrium time is 20-60min.
Further, a two-dimensional center cutting technology is adopted to realize the switching of a gas chromatography-FID detection method and a gas chromatography-mass spectrometry combination method.
Further, the gas chromatography conditions are:
carrier gas: he;
chromatographic column: polyethylene glycol chromatographic column, specification: 30 m.times.250 μm.times.0.5. Mu.m;
sample injection mode: split sample injection, split ratio 5:1, a step of;
column flow rate: 0.5-2mL/min;
sample inlet temperature: 250 ℃;
transmission line temperature: 250 ℃.
Further, the gas chromatography column box temperature-raising program is set as follows: the furnace temperature is 40 ℃ and kept for 3min; then heating to 100 ℃ at 10 ℃/min; heating to 110 ℃ at 20 ℃/min, and preserving heat for 3min; then heating to 230 ℃ at 40 ℃/min, and preserving heat for 12min.
Further, the FID detector conditions are:
temperature: 300 ℃;
h2 flow rate: 30mL/min;
air flow rate: 400mL/min;
tail blow flow rate: 25mL/min;
FID damper tube specification: 1 m.times.180. Mu.m.times.0. Mu.m, flow rate: 2.5mL/min.
Further, the mass spectrometry conditions are:
mass spectrometry ionization mode: an electron bombardment ionization source;
ion source temperature: 230 ℃;
four-stage bar temperature: 150 ℃;
the acquisition mode is as follows: selecting ion scanning;
gain factor: 5, a step of;
solvent delay: 4.6min;
damping tube specification: 1.36 m.times.150. Mu.m.times.0. Mu.m, flow rate: 2.5mL/min.
Further, the alcohol is methanol, ethanol, propanol or butanol, and the ketone is acetone; quantitatively measured mass spectrum characteristic ions: methanol, ethanol, propanol and butanol are 31, acetone: 43.
further, the alcohol is methanol, ethanol, propanol or butanol, and the ketone is acetone; the mass spectrum characteristic ions of qualitative measurement are respectively: methanol: 29 32; ethanol: 45 46; propanol: 59; butanol: 41 56; acetone: 58.
according to the method for measuring the trace alcohol and ketone substance content in the transformer insulating oil, provided by the invention, the test conditions are optimized by improving the standard sample preparation method, and the headspace automatic sample injection is adopted, so that the test of various alcohols such as methanol, ethanol, propanol (n-propanol and isopropanol), butanol and ketone substances such as acetone can be realized by single sample injection; the switching technology is selected, so that the switching of the two methods of gas chromatography-mass spectrometer combination and gas chromatograph FID detection method is realized in the same set of device; the measuring method of the invention further improves the measuring precision of trace substances in the insulating oil, expands the measuring range, has good repeatability and stability, and improves new judging standards and ideas for the aging evaluation of the cellulose insulating material in the transformer.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:
FIG. 1 is a flowchart of a method for measuring the content of trace alcohols and ketones in transformer insulating oil provided by an embodiment of the invention;
FIG. 2 is a schematic diagram of a Dean switch flow path;
FIG. 3 is a chart showing quantitative measurement of alcohol substances by GC-FID method according to an embodiment of the present invention;
FIG. 4 is a graph showing quantitative acetone measurement by GC-MS detection according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a standard addition method standard curve;
FIG. 6 is a graph showing a fitted standard curve of propanol according to an embodiment of the present invention;
fig. 7 is a flow chart II of a method for measuring the content of trace alcohols and ketones in insulating oil provided by the embodiment of the invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.
Referring to fig. 1, the invention provides a method for measuring the content of trace alcohols and ketones in insulating oil, which comprises the following steps:
s110: and (3) obtaining transformer insulating oil to be detected as a base solution, adding standard solutions of alcohols and/or ketones to be detected into the base solution, and preparing a series of standard samples with different addition concentrations.
Standard solutions of alcohols or ketones can be added into the base solution respectively, or can be added simultaneously, and the base solution is selected according to detection requirements. The standard solution used may be purchased from a standard substance center. In the embodiment of the invention, a plurality of samples with different preset adding concentrations of alcohols and/or ketones to be detected are required to be prepared so as to obtain peak areas corresponding to different adding concentrations.
As a preferred embodiment, the specific preparation method of the standard solution is as follows:
1) Taking 15mL of background sample oil to be detected, adding a standard solution of methanol, ethanol, propanol, butanol and acetone to be detected, accurately recording the mass of the sample oil, and preparing a No. 1 mother solution with the concentration of 3 mug/mL;
2) And then 15mL of background sample oil to be detected is taken, and the mother solution No. 1 is diluted to be used as the mother solution No. 2.
3) According to the concentration progressive sequence, diluting the No. 2 mother solution to prepare 5mL standard samples, and sequentially marking the 5 standard samples as 1, 2, 3, 4 and 5 standard samples.
S120: and extracting volatile substance gases corresponding to the standard sample by adopting a headspace sampling method, and separating and detecting alcohols and/or ketones to be detected in the volatile substance gases by using a gas chromatography-FID (GC-FID) detection method or a gas chromatography-mass spectrometry (GC-MS) method to obtain the chromatogram peak areas of the alcohols and/or ketones to be detected corresponding to the standard sample.
In this step, three main aspects are included:
1) Headspace sample injection
The headspace sampling principle is to put a sample to be tested into a closed container, volatilize volatile components from a sample matrix by heating and raising temperature, reach equilibrium in gas-liquid (or gas-solid) two phases, directly extract top gas for chromatographic analysis, and thus detect the components and the content of the volatile components in the sample. The headspace sampling technology can avoid lengthy and complicated sample pretreatment process, avoid the interference of organic solvent on analysis and reduce the pollution to chromatographic columns and sample inlets. Therefore, during sample injection, the selection of temperature and time will affect the separation and collection of subsequent samples. Preferably, the equilibrium temperature is 60-90 ℃ and the equilibrium time is 20-60min; in one embodiment of the present invention, the parameters during headspace sampling are set as follows:
headspace bottle loading: 5mL;
equilibrium temperature: 80 ℃;
equilibration time: 30min.
2) Detection mode selection
The detection mode is selected mainly by adopting a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combination method.
The method of gas chromatograph-mass spectrometer combination can be used for more accurate quantification, but because the mass spectrometer needs to be vacuumized for about 4 hours for tuning when being started, the parameters of MS can be changed after the tuning, standard samples need to be reconstituted each time, a standard curve is made, and the preparation time is about 6 hours.
Therefore, the FID detector can be added in the gas chromatograph, and preliminary qualitative and quantitative detection can be rapidly performed by the GC-FID detection method. While GC-MS testing may be selected for the purpose of accurate quantitative analysis.
In order to facilitate the switching, a two-dimensional center cutting technology is recommended to realize the switching of two measurement modes, the switching does not need physical switching, the program control is realized completely by a method file, and the method is convenient and quick and convenient to operate.
Preferably, the switching can be achieved by installing a Deans Switch, which is a kind of flow path switching device of a micro flow path, which is used for a center cutting function in many cases. The switching of the flow paths is achieved by controlling the gas pressure and flow, rather than by conventional mechanically rotating valves. When switching, the schematic diagram of the system flow path is shown in fig. 2, a sample is firstly separated through a gas chromatographic column, and when a Dean Switch electromagnetic valve PMC in the middle is opened, a compound separated and flowing out through the chromatographic column enters an FID detector from a damping tube at the lower part for detection, as shown in fig. 2 (a); when the solenoid valve is closed, the separated and eluted compounds enter the mass spectrum MS detector from the upper damper tube for detection, as shown in fig. 2 (b).
3) Testing
After the test mode is selected, conditions can be set, an automatic sample injection number is set, and GC-FID or GC-MS test is carried out on the sample to be tested.
The test conditions are set to closely influence the test result, such as the separation effect is influenced by the selection of the chromatographic column, the separation degree and the detection lower limit are influenced by the split ratio, and the separation degree and the peak time are influenced by the temperature programming.
As a preferred example, the gas chromatography conditions are:
carrier gas: he is a compound of formula He,
chromatographic column: polyethylene glycol chromatography columns, such as DB-WAX gas chromatography column, specification: 30 m.times.250 μm.times.0.5. Mu.m;
sample injection mode: split sample injection, wherein the split ratio is 5:1;
column flow rate: 0.5-2mL/min; specifically, it may be 1mL/min, 1.5mL/min, etc.
Sample inlet temperature: 250 ℃;
transmission line temperature: 250 ℃;
the chromatographic column box temperature program is set as follows: the furnace temperature is 40 ℃ and kept for 3min; then heating to 100 ℃ at 10 ℃/min; heating to 110 ℃ at 20 ℃/min, and preserving heat for 3min; then heating to 230 ℃ at 40 ℃/min, and preserving heat for 12min.
The FID detector conditions were:
temperature: 300 ℃;
H 2 flow rate: 30mL/min;
air flow rate: 400mL/min;
tail blow flow rate: 25mL/min;
FID damper tube specification: 1 m.times.180. Mu.m.times.0. Mu.m, flow rate: 2.5mL/min.
The mass spectrum conditions are as follows:
mass spectrometry ionization mode: an electron bombardment ionization source;
ion source temperature: 230 ℃;
four-stage bar temperature: 150 ℃;
the acquisition mode is as follows: selecting ion scanning;
gain factor: 5, a step of;
solvent delay: 4.6min;
damping tube specification: 1.36 m.times.150. Mu.m.times.0. Mu.m, flow rate: 2.5mL/min.
The mass spectrometry quantitative and qualitative ion settings for several common alcohols and ketones are shown in table 1:
table 1 mass spectrometry quantitative and qualitative ion settings for several common alcohols and ketones
| Methanol | Ethanol | Propanol (propanol) | Butanol (Butanol) | Acetone (acetone) | |
| Quantification of ions | 31 | 31 | 31 | 31 | 43 |
| Qualitative ions | 29.32 | 45，46 | 59 | 41，56 | 58 |
FIG. 3 is a diagram showing a scanning spectrum of an alcohol substance by a gas chromatography-FID detection method according to an embodiment of the present invention, wherein the adding amount of the alcohol substance in the mother liquor No. 1 is 3 μg/mL, and the detected alcohol substance comprises: methanol, ethanol, propanol, butanol.
FIG. 4 is a graph showing acetone quantitative measurement by GC-MS detection according to an embodiment of the present invention.
In the spectra of the above examples, the peak areas RSD were each calculated to be 5% or less (about 3%) by measuring the spectra repeatedly.
S130: and establishing a standard curve according to the peak area of the chromatogram and the added concentration in the standard sample, fitting to obtain a linear equation, and calculating the content of the alcohol and/or ketone substances to be detected in the base solution according to the linear equation.
The invention adopts a standard adding method, and the principle is that a series of standard solutions with known concentrations are added into a sample to be detected, the response values of the samples with different addition amounts are measured, the abscissa is the addition standard amount, and the ordinate is the response value, and a standard curve is established. The original content in the sample is then back-deduced by means of the established standard curve. The standard curve is shown in FIG. 5, in which
The standard curve can be expressed as a linear equation: y=ax+b, where Y is the peak area, X is the standard addition, a is the slope, b is the intercept;
from the basic relationship of the standard addition method, a similar linear equation can be derived:
I.e.
Two-equation contrast a=yi/Xi, b=yi
Xi=yi/a=b/a
The content of the target compound in the sample to be measured can be calculated according to the linear regression result, and as seen from fig. 3, the intersection point (absolute value) of the straight line and the abscissa is equal to the content of the target compound in the sample to be measured when Y is equal to 0, so that the measurement is more accurate.
In one embodiment, a standard curve is fitted based on measured peak areas of the different concentrations of the No. 1, 2, 3, 4, 5 standard, and the added concentrations of the No. 1, 2, 3, 4, 5 standard. As shown in fig. 6, in an example, a fitted curve of propanol with y=123.140147x+7634.644442 can be calculated, and the propanol content in the background sample oil is 7634.644442/123.14014 =62 μg/L.
Similarly, for other alcohols and ketones to be tested, a series of standard samples can be prepared according to the above flow, and the content of the substances to be tested can be calculated according to the measured peak area and the standard curve obtained by fitting.
Further, the measurement method of the present invention may further comprise the steps of:
s140: obtaining the corresponding chromatogram peak areas of the alcohols and/or ketones to be detected in other similar to-be-detected transformer insulating oil;
s150: and calculating the content of the alcohols and/or ketones to be detected in the insulating oil to be detected of the same kind according to the linear equation obtained by fitting.
Referring to FIG. 3, other types of insulating oil to be tested can be prepared as the sample to be tested while preparing the standard solution, and the sample is sampled and detected together, and the peak area Y of the chromatogram is obtained by adopting GC-FID or GC-MS test 1 Then X is obtained according to the standard curve obtained by the fitting 1 The corresponding content of the alcohols and/or ketones is (X 1 +b/a)。
Or, translating the obtained standard curve by b/a units along the X axis right, namely, increasing b/a correspondingly to the whole, and obtaining a relation equation of the peak area and the actual concentration of the to-be-detected object in the to-be-detected solution: y=ax Actual practice is that of Wherein Y is the peak area, X is the actual alcohol/ketone concentration in the solution to be detected, and the corresponding content Y/a of the alcohol/ketone substances can be directly obtained according to the curve.
In the test method of the embodiment of the invention, the detection limits of all substances are respectively as follows:
gas chromatography-mass spectrometry: methanol 1.8. Mu.g/L, ethanol 4.7. Mu.g/L, propanol 3.5. Mu.g/L, butanol. Mu.g/L.
Gas chromatography FID method: 118.6. Mu.g/L of methanol, 98.3. Mu.g/L of ethanol, 372. Mu.g/L of propanol and 121. Mu.g/L of butanol.
The measurement method of the present invention has been described above with reference to measurement of methanol, ethanol, propanol (n-propanol and isopropanol), butanol, but the measurement method of the present invention is not limited thereto, and the measurement method of the present invention can be used for measurement of the content of other alcohols in insulating oil.
According to the determination method, a standard addition method is adopted, alcohol and/or ketone substances with different contents are added into transformer insulating oil to prepare a standard sample, then a gas chromatography FID detection method or a gas chromatography-mass spectrometry combined method is adopted to test to obtain the peak area of a chromatogram, and then a standard curve is fitted, so that the content of a target compound in a sample to be detected can be calculated. Wherein the alcohol can be methanol, ethanol, propanol (n-propanol and isopropanol), butanol, etc.; the ketone material can be acetone, methyl ethyl ketone, etc.
The determination method of the invention adopts a standard addition method to prepare the standard solution, and is especially used for detecting the condition that the target interfering substances exist in the sample. Through the test of the method, alcohol substances with the content of more than 10 mug/L are found in unused transformer insulating oil of various types, which indicates that the insulating oil has no ready-made insulating oil blank sample, which is not reported in the prior literature, and also indicates that in the traditional methanol measurement of the insulating oil, the standard curve method is adopted, the standard insulating oil is used as the blank, methanol is added for measurement, and the used blank is not a real blank, so the measurement repeatability and stability are poor, and engineering application is difficult.
According to the method for measuring the trace and alcohol content in the insulating oil, a headspace automatic sample injection mode is adopted for sample injection, and the test of various alcohols such as methanol, ethanol, propanol (n-propanol and isopropanol), butanol and other ketone substances such as acetone can be realized through single sample injection by improving a standard sample preparation method; and by improving the switching method, the switching of the gas chromatograph-mass spectrometer combination method and the gas chromatograph FID detection method can be realized in one set of system, and the method has the advantages of accurate measurement, good repeatability and time saving and rapidness. The measuring method of the invention further improves the measuring precision, expands the measuring range, has good repeatability and stability of measurement, and improves new judgment standards and ideas for the aging evaluation of the cellulose insulating material in the transformer.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (4)
1. The method for measuring the content of trace alcohols and ketones in the transformer insulating oil is characterized by comprising the following steps of:
the method comprises the steps of obtaining transformer insulating oil to be detected as a base solution, adding standard solutions of alcohols and/or ketones to be detected into the base solution, and preparing a series of standard samples with different addition concentrations;
extracting volatile substance gases corresponding to the standard sample by adopting a headspace sampling method, and separating and detecting alcohols and/or ketones to be detected in the volatile substance gases by using a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combination method to obtain the chromatogram peak areas of the alcohols and/or ketones to be detected corresponding to the standard sample;
establishing a standard curve according to the peak area of the chromatogram and the added concentration in the standard sample, fitting to obtain a linear equation, and calculating the content of alcohols and/or ketones to be detected in the base solution according to the linear equation;
the operation method uses a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combination method to separate and detect alcohols and/or ketones to be detected in volatile substance gas:
wherein, the gas chromatography conditions are:
carrier gas: he;
chromatographic column: polyethylene glycol chromatographic column, specification: 30 m.times.250 μm.times.0.5. Mu.m;
sample injection mode: split sample introduction, wherein the split ratio is 5:1;
column flow rate: 0.5-2mL/min;
sample inlet temperature: 250 ℃;
transmission line temperature: 250 ℃; the temperature programming of the gas chromatographic column box is set as follows: the furnace temperature is 40 ℃ and kept for 3min; then heating to 100 ℃ at 10 ℃/min; heating to 110 ℃ at 20 ℃/min, and preserving heat for 3min; then heating to 230 ℃ at 40 ℃/min, and preserving heat for 12min;
the FID detector conditions for the gas chromatograph are:
temperature: 300 ℃;
h2 flow rate is 30mL/min;
air flow rate: 400mL/min;
tail blow flow rate: 25mL/min;
FID damper tube specification: 1 m.times.180. Mu.m.times.0. Mu.m, flow rate: 2.5 mL/min;
the mass spectrum conditions are as follows:
mass spectrometry ionization mode: an electron bombardment ionization source;
ion source temperature: 230 ℃;
four-stage bar temperature: 150 ℃;
the acquisition mode is as follows: selecting ion scanning;
gain factor: 5, a step of;
solvent delay: 4.6min;
damping tube specification: 1.36 m.times.150. Mu.m.times.0. Mu.m, flow rate: 2.5 mL/min;
the alcohol substances are methanol, ethanol, propanol or butanol, and the ketone substances are acetone; quantitatively measured mass spectral features
Ion: methanol, ethanol, propanol and butanol are 31, acetone: 43.
The alcohol substances are methanol, ethanol, propanol or butanol, and the ketone substances are acetone; the mass spectrum characteristic ions of qualitative measurement are respectively: methanol: 29 32; ethanol: 45 46; propanol: 59; butanol: 41 56; acetone: 58.
2. the method for determining the content of trace alcohols and ketones in transformer insulating oil according to claim 1, further comprising obtaining the corresponding chromatogram peak areas of the alcohols and/or ketones to be detected in other similar transformer insulating oil to be detected by using a gas chromatography-FID detection method or a gas chromatography-mass spectrometry combination method by adopting a headspace sampling method, and obtaining the content of the alcohols and/or ketones to be detected according to a linear equation obtained by fitting.
3. The method for determining the content of trace alcohols and ketones in transformer insulating oil according to claim 1, wherein the balance temperature of the headspace sampling method is 60-90 ℃ and the balance time is 20-60min.
4. The method for determining the content of trace alcohols and ketones in transformer insulating oil according to claim 1, wherein the switching between a gas chromatography-FID detection method and a gas chromatography-mass spectrometry method is realized by adopting a two-dimensional center cutting technology.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106706821A (en) * | 2016-11-18 | 2017-05-24 | 云南电网有限责任公司电力科学研究院 | Method and system for detecting methanol concentration of transformer insulation oil |
| CN107102085A (en) * | 2017-05-25 | 2017-08-29 | 云南电网有限责任公司电力科学研究院 | The sample-pretreating method of methanol content measuring in a kind of insulating oil |
| CN107515260A (en) * | 2017-08-16 | 2017-12-26 | 重庆大学 | The assay method of methanol content in a kind of insulating oil |
| CN108459102A (en) * | 2018-03-23 | 2018-08-28 | 中海油气(泰州)石化有限公司 | Antioxidant content assay method in transformer oil |
-
2019
- 2019-05-10 CN CN201910389409.XA patent/CN110082469B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106706821A (en) * | 2016-11-18 | 2017-05-24 | 云南电网有限责任公司电力科学研究院 | Method and system for detecting methanol concentration of transformer insulation oil |
| CN107102085A (en) * | 2017-05-25 | 2017-08-29 | 云南电网有限责任公司电力科学研究院 | The sample-pretreating method of methanol content measuring in a kind of insulating oil |
| CN107515260A (en) * | 2017-08-16 | 2017-12-26 | 重庆大学 | The assay method of methanol content in a kind of insulating oil |
| CN108459102A (en) * | 2018-03-23 | 2018-08-28 | 中海油气(泰州)石化有限公司 | Antioxidant content assay method in transformer oil |
Non-Patent Citations (3)
| Title |
|---|
| Methanol detection in transformer oils using gas chromatography and ion trap mass spectrometer;S. Y. Matharage 等;《2014 IEEE International Conference on Liquid Dielectrics》;20140703;1-4 * |
| Study of field aged transformer insulation oil properties using GC-MS;Muhammad Ali Mehmood 等;《2018 IEEE International Conference on High Voltage Engineering and Application》;20181231;1-4 * |
| 顶空-气相色谱/质谱联用法检测绝缘油中的甲醇;杨宇玲 等;《云南电力技术》;20171231;第45卷(第6期);109-112 * |
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