Chromatographic methods of analysis: gas chromatography method. Gas chromatography

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Zlatkovsky Mikhail

Does Russia need a political cartoon today?

Mikhail Zlatkovsky, a famous cartoonist whose exhibition recently opened at the Andrei Sakharov Center, is a guest of the “Cultural Response” program on Mayak radio.

ZLATKOVSKY: It’s incredibly interesting to do daily caricature. But besides caricatures, I do a lot of interesting things: illustrations for books, posters, large philosophical works. Cartooning is a daily challenge. I've dreamed about this all my life. And for the last four years, I’ve finally been working. And all my life I had to work as a designer in order to somehow earn money. In Soviet times, with my vision of the world, it was impossible to draw every day.

– After the scandalous exhibition “Beware of Religion!” was held at the Sakharov Center. Is the museum management now more strict in the selection of the works it exhibits? Was there any prior censorship?

ZLATKOVSKY: It's the other way around. I didn’t want to exhibit anti-clerical things, but the director of the museum, Yuri Samodurov, asked me, saying that we should not bend. Everything that has been done against pseudo-churchism, pseudo-clericalism must be exposed. We put it up, only with a small note that we are not offending anyone and that these drawings cannot be considered as an outrage against a particular religion.

– But that drawing, which caused a lawsuit and almost the closure of a newspaper in one of the provincial cities of Russia, also did not offend anyone?

ZLATKOVSKY: It all depends on local conditions and desire. Remember the Danish scandal with 12 drawings of the Prophet Muhammad? This is just an excuse to inflate this or that problem. The caricature itself does not particularly offend anyone. Perhaps in history we will find only two or three cases when a caricature seriously provoked a monstrous reaction. It was Napoleon who demanded that English cartoonists be handed over to him and destroyed, or simply prohibited from working if England could not hand them over to the guillotine. The second case is Adolf Hitler, who compiled a list for hanging cartoonists. This list includes our Kukryniksy, Efimov, and David Lowe. And everything else is a provocation.

ZLATKOVSKY: This is a biased caricature. There was probably no such concept in the world that was formed in Soviet times. The amazing Soviet concept of “satire”, which was absolutely unpunished. They sat here quietly, and their enemies could do nothing to them. Of course, this is agitprop, not a caricature. I am an author's cartoonist. No one puts pressure on me, no one orders me. This is just my social position. They did not have this social position.

– Is political cartooning a biased genre today anyway?

ZLATKOVSKY: It all depends on the level of culture and on the level of knowledge of the social life of a particular cartoonist. In this vast country I will not find a single example of biased caricature. This is always the author's caricature. Another thing is that there is no serious political caricature. This same thing is probably only permissible for one person to do. This is Viktor Bogorad from St. Petersburg, who sends drawings to two newspapers every day by fax or via the Internet. These are “The Moscow Times” and “Vedomosti”. He has a political cartoon there. A wonderful artist Seryozha Tyunin, who paints the economy in Kommersant. That's it, nowhere else, with the exception of small provincial newspapers, where there is still something. We must talk about the central press.

– Is the level of caricature today high or not?

ZLATKOVSKY: Technically very high, theoretically and in terms of its potential to influence politics from the outside - very high. But we simply don’t have newspapers that would attract, for example, Sasha Sergeev to work. I can name another 50 names in Russia who could well appear in the newspaper every day at the world level, but these newspapers do not exist.

– You said that a political cartoon cannot seriously offend anyone, is no one really offended?

ZLATKOVSKY: They are offended. De Gaulle's long-term scandal is well known.

– I’m talking about today’s Russia.

ZLATKOVSKY: We don’t have that caricature that you can be offended by. Drawings appear with portrait likenesses of deputies, but these are always very complimentary things. There are a large number of caricatures with Putin’s face, but this is also absolutely complimentary. These are more like PR campaigns. Many politicians would even pay if their face appeared often enough in cartoons, as at one time many wanted to get into Shenderovich’s “Dolls”. But this is PR. There is no hard caricature, not because the artist cannot do it, but because no media outlet will dare to do it.

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Awards:

Mikhail Mikhailovich Zlatkovsky(August 21, Khristoforovka village, Second Left Lamki village, Tambov region) - Russian artist; political artist-observer of the newspaper “Novye Izvestia”.

Biography

At the same time (in 1988), his father disowned Mikhail Zlatkovsky. My father was a military scientist (Doctor of Science, Professor). Under threat of dismissal from service, he was forced to write a statement to the party committee of the Ministry of Defense: “I have not maintained a relationship with my son for a long time, I do not share his political views, and my attempts to set my son on the right path were in vain.”, but the son’s relationship with his father remained the same after that.

From 1997 to 1997 he lived and worked in the USA, then returned to Russia.

Chief artist of Moscow News, 1997-1998.
Chief artist of the Literary Newspaper, 1998-2002.
Chief artist of the magazine "Business Chronicle", 2002-2003.
Chief artist of the newspaper and political cartoonist "Novye Izvestia", 2003-2005.

Currently, he continues to draw cartoons for the newspaper Novye Izvestia, which he values for its independent position.

Member of the French Academy of Humorous Arts, Academy of Authorities (St. Petersburg), International Academy of Pedagogy. Member of the Union of Journalists of the USSR and the Russian Federation (since 1985), member of the Union of Artists of the USSR (since 1988), founder and president of the Union of Cartoonists of Russia, Secretary of the Union of Journalists of Russia, from 1988 until expulsion in 2007, he was Vice-President of the international organization of cartoonists - FECO.

Researcher in the “History and Theory of Art” sector of the Institute of Cultural Studies of the Ministry of Culture of the Russian Federation. Author of several articles on caricature and books “History of Russian Caricature”, “History of World Caricature”. Publisher of the quarterly magazine "Caricature", 1999-2002. Supervisor and consultant of many dissertations, diploma and coursework on caricature in Russia and abroad.

President (18 times) and jury member (49 times) of many international cartoon competitions.

Family

Married. First marriage in 1967 with Nadezhda, 1943, two children - Anastasia, 1970, tennis coach, and Philip, 1975, designer. Second marriage, 1994, Marina Filatova, 1958, journalist, writer.

Grandson of Kozma Mikolaevich Zlatkovsky, born in 1881, a priest of the Russian Orthodox Church in the village of Anakhino, Oryol region, who did not accept the “Sergian heresy” (see “Catacomb Church”) and went underground in 1924 - the Russian Orthodox Catacomb Church, convicted under Art. . 58 and executed by the NKVD in Tula on November 26, 1937.

Awards

1970 - Silver medal of VDNKh
1981 - “Golden Calf”, award of the “12 Chairs” Club of the “Literary Gazette”
2002 - “Golden Pen” - the highest award of the Union of Journalists of Russia.
Awarded more than 260 national and international awards in various genres of art. Among them are the main and first prizes at cartoon competitions in Canada, Italy, Japan, Poland, the USA, Iran and other countries.
2009 - Knight of the Legion of Honor, France
2010 - Honorary foreign member of the Azerbaijan Cartoonists Union
2011 - At the XXXIX Satire Festival in Forte dei Marmi, (Italy) awarded the prize “Best Foreign Satirist”
2012 -Honorary foreign member of the Union of Artists of Armenia
2012 - Honorary foreign member of the Union political. cartoonists of Canada
2013 - Honorary Foreign Member of the Union of Cartoonists and Illustrators of China
2014 -Honorary Foreign Member of the Union of Cartoonists of Turkey

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An excerpt characterizing Zlatkovsky, Mikhail Mikhailovich

- No, promise me, I won’t let you in, my dear, my benefactor...
- Dad! - the beauty repeated again in the same tone, - we will be late.
- Well, au revoir, [goodbye,] goodbye. Do you see?
- So tomorrow you will report to the sovereign?
- Definitely, but I don’t promise Kutuzov.
“No, promise, promise, Basile, [Vasily,],” Anna Mikhailovna said after him, with the smile of a young coquette, which once must have been characteristic of her, but now did not suit her exhausted face.
She apparently forgot her years and, out of habit, used all the old feminine remedies. But as soon as he left, her face again took on the same cold, feigned expression that was on it before. She returned to the circle, in which the Viscount continued to talk, and again pretended to listen, waiting for the time to leave, since her work was done.
– But how do you find all this latest comedy du sacre de Milan? [Milan anointing?] - said Anna Pavlovna. Et la nouvelle comedie des peuples de Genes et de Lucques, qui viennent presenter leurs voeux a M. Buonaparte assis sur un throne, et exaucant les voeux des nations! Adorable! Non, mais c"est a en devenir folle! On dirait, que le monde entier a perdu la tete. [And here is a new comedy: the peoples of Genoa and Lucca express their desires to Mr. Bonaparte. And Mr. Bonaparte sits on the throne and fulfills the desires of the peoples. 0! this is amazing! No, you can go crazy from this. You will think that the whole world has lost its head.]
Prince Andrei grinned, looking straight into Anna Pavlovna’s face.
“Dieu me la donne, gare a qui la touche,” he said (the words Bonaparte said when laying on the crown). “On dit qu"il a ete tres beau en prononcant ces paroles, [God gave me the crown. Trouble is the one who touches it. “They say he was very good in saying these words,” he added and repeated these words again in Italian: “Dio mi la dona, guai a chi la tocca.”
“J"espere enfin," Anna Pavlovna continued, "que ca a ete la goutte d"eau qui fera deborder le verre. Les souverains ne peuvent plus supporter cet homme, qui menace tout. [I hope that this was finally the drop that overflows the glass. The sovereigns can no longer tolerate this man who threatens everything.]
– Les souverains? Je ne parle pas de la Russie,” said the Viscount politely and hopelessly: “Les souverains, madame!” Qu"ont ils fait pour Louis XVII, pour la reine, pour Madame Elisabeth? Rien,” he continued animatedly. “Et croyez moi, ils subissent la punition pour leur trahison de la cause des Bourbons. Les souverains? Ils envoient des ambassadeurs complimenter l"usurpateur. [Sirs! I'm not talking about Russia. Sirs! But what did they do for Louis XVII, for the queen, for Elizabeth? Nothing. And, believe me, they are being punished for their betrayal of the Bourbon cause. Sirs! They send envoys to greet the thief of the throne.]
And he, sighing contemptuously, changed his position again. Prince Hippolyte, who had been looking at the Viscount through his lorgnette for a long time, suddenly at these words turned his whole body to the little princess and, asking her for a needle, began to show her, drawing with a needle on the table, the coat of arms of Condé. He explained this coat of arms to her with such a significant air, as if the princess had asked him about it.
- Baton de gueules, engrele de gueules d "azur - maison Conde, [A phrase that is not translated literally, as it consists of conventional heraldic terms that are not used entirely accurately. The general meaning is this: The coat of arms of Conde represents a shield with red and blue narrow jagged stripes ,] - he said.
The princess listened, smiling.
“If Bonaparte remains on the throne of France for another year,” the Viscount continued the conversation that had begun, with the air of a man who does not listen to others, but in a matter that is best known to him, following only the course of his thoughts, “then things will go too far.” Through intrigue, violence, expulsions, executions, society, I mean good society, French, will be destroyed forever, and then...
He shrugged and spread his arms. Pierre wanted to say something: the conversation interested him, but Anna Pavlovna, who was watching him, interrupted.
“Emperor Alexander,” she said with the sadness that always accompanied her speeches about the imperial family, “announced that he would let the French themselves choose their mode of government.” And I think there is no doubt that the whole nation, freed from the usurper, will throw itself into the hands of the rightful king,” said Anna Pavlovna, trying to be polite to the emigrant and royalist.
“This is doubtful,” said Prince Andrei. “Monsieur le vicomte [Mr. Viscount] quite rightly believes that things have already gone too far. I think it will be difficult to go back to the old ways.
“As far as I heard,” Pierre, blushing, again intervened in the conversation, “almost the entire nobility has already gone over to Bonaparte’s side.”
“That’s what the Bonapartists say,” said the Viscount, without looking at Pierre. – Now it is difficult to know the public opinion of France.
“Bonaparte l"a dit, [Bonaparte said this],” said Prince Andrei with a grin.
(It was clear that he did not like the Viscount, and that, although he did not look at him, he directed his speeches against him.)
“Je leur ai montre le chemin de la gloire,” he said after a short silence, again repeating the words of Napoleon: “ils n"en ont pas voulu; je leur ai ouvert mes antichambres, ils se sont precipites en foule”... Je ne sais pas a quel point il a eu le droit de le dire. [I showed them the path of glory: they did not want; I opened my halls to them: they rushed in a crowd... I don’t know to what extent he had the right to say so.]
“Aucun, [None],” the Viscount objected. “After the Duke’s murder, even the most biased people stopped seeing him as a hero.” “Si meme ca a ete un heros pour certaines gens,” said the Viscount, turning to Anna Pavlovna, “depuis l"assassinat du duc il y a un Marietyr de plus dans le ciel, un heros de moins sur la terre. [If he was a hero for some people, then after the murder of the Duke there was one more martyr in heaven and one less hero on earth.]
Before Anna Pavlovna and the others had time to appreciate these words of the Viscount with a smile, Pierre again burst into the conversation, and Anna Pavlovna, although she had a presentiment that he would say something indecent, could no longer stop him.
“The execution of the Duke of Enghien,” said Monsieur Pierre, “was a state necessity; and I precisely see the greatness of the soul in the fact that Napoleon was not afraid to take upon himself the sole responsibility in this act.
- Dieul mon Dieu! [God! my God!] - Anna Pavlovna said in a terrible whisper.
“Comment, M. Pierre, vous trouvez que l"assassinat est grandeur d"ame, [How, Monsieur Pierre, you see the greatness of the soul in murder," said the little princess, smiling and moving her work closer to her.

; political artist-observer of the newspaper “Novye Izvestia”.

Biography

From 1997 to 1997 he lived and worked in the USA, then returned to Russia.

Chief artist of Moscow News, 1997-1998.
Chief artist of the Literary Newspaper, 1998-2002.
Chief artist of the magazine "Business Chronicle", 2002-2003.
Chief artist of the newspaper and political cartoonist "Novye Izvestia", 2003-2005.

Currently, he continues to draw cartoons for the newspaper Novye Izvestia, which he values for its independent position.

President (18 times) and jury member (49 times) of many international cartoon competitions.

Family

Married. First marriage in 1967 with Nadezhda, 1943, two children - Anastasia, 1970, tennis coach, and Philip, 1975, designer. Second marriage, 1994, Marina Filatova, 1958, journalist, writer.

GAS CHROMATOGRAPHIC ANALYSIS OF INORGANIC SUBSTANCES

The development of gas chromatography methods in the analysis of inorganic substances lags behind in comparison with gas chromatography of organic substances. Firstly, this is due to the aggressiveness of many inorganic compounds towards adsorbents, stationary phases and materials from which equipment for gas chromatographic analyzes is usually made. Secondly, gas chromatography of inorganic substances began to develop later than gas chromatography of organic compounds. This is due to the fact that for the analysis of inorganic substances there are classical methods that are superior in accuracy and speed to methods for analyzing organic compounds. However, gas chromatography already makes it possible to analyze the compounds of almost all elements of the periodic table.

REQUIREMENTS FOR ANALYZED SUBSTANCES

Not all substances can be analyzed by the gas chromatographic method, but only those that meet certain requirements, the main ones of which are listed below.

1. Volatility. It is enough that the vapor pressure of the substance at the operating temperature of the column is low. A substance whose vapor pressure is higher than that of another is considered more volatile. The presence of large dipole moments, polarization, and hydrogen bonding lead to a decrease in volatility; ionic and highly polar compounds are non-volatile.

2. Stability. Quantitative analysis of a substance is possible if it evaporates in a dispenser and elutes without decomposition, i.e. it is heat-resistant. When substances decompose, false peaks characteristic of decomposition products appear on the chromatogram, which leads to errors in the analysis. It is possible to analyze compounds for which a reproducible decomposition technique has been developed.

3. Inertia. The substance should not form strong solvates when dissolved in a liquid stationary phase, and should not react with the materials from which the chromatograph parts are made.

4. Ease of obtaining. When performing quantitative analysis, it is desirable to work with compounds that are easy to obtain in quantitative yield.

These requirements are, as a rule, met to a greater extent by organic substances. However, in recent years, methods for gas chromatographic analysis of various metals and their inorganic and organic compounds have been developed.

ANALYSIS OF METALS AND THEIR COMPOUNDS

Analysis of free metals is possible using ultra-high temperature chromatography equipment. There are few metal compounds that are volatile at relatively low temperatures: halides, alcoholates, various chelates, hydrides.

Free metals. Methods for chromatography of free metals at ultra-high thousand-degree temperatures have been developed. For example, it was possible to carry out direct gas chromatographic determination of zinc, cadmium and magnesium in alloys such as solders and light alloys based on tin, lead and bismuth without chemical treatment. Zinc, cadmium and mercury are separated in the form of vapors of these metals. It has not yet been possible to separate potassium and sodium metals in the form of vapor; they elute together at 600--1000 0 C. In the future, direct gas chromatographic separation of metals can be used to purify metals and their alloys from ultra-small amounts of impurities.

Metal hydrides. In a number of works, gas chromatographic analysis of volatile metal hydrides was carried out. Direct separation of hydrides of antimony, tin, titanium, niobium and tantalum is possible. When chromatography of metal hydrides, one should take into account their high reactivity, tendency to hydrolysis and easy oxidation. Gas chromatographic analysis of hydrides is possible only in the absence of oxygen in the system.

Metal halides. Transition metal halides can be separated and quantified using the gas chromatographic method. The separation of volatile chlorides can be achieved by thermochromatography in combination with complexation. The separation of volatile chlorides Sb, Sn, In, Cd, Zr, Hf, Nb, Ta, Mo, Tc, Re, Ru, Os by thermochromatography using a temperature gradient from 600 to 25°C is described. At significantly lower temperatures it is possible to determine gallium, germanium, arsenic, antimony and silicon chlorides. The main difficulty encountered in the chromatography of metal halides is their high reactivity. In a column at elevated temperatures, they react with many liquid stationary phases and with the metal surfaces of chromatograph parts, including columns. Halides are easily hydrolyzed, so even traces of moisture should be removed from the carrier gas. Since adsorbents are often more inert than liquid stationary phases, gas adsorption chromatography has certain advantages over gas-liquid chromatography when analyzing metal halides.

Of all the various metal compounds used for gas chromatographic analysis, chelates are of greatest practical interest. Chelates of almost any metal can be obtained. Currently, many chelates have been synthesized whose volatility and thermal stability meet the requirements of gas chromatography. Metal chelates can be obtained in quantitative yield either by reacting metal chlorides with the corresponding ligands, or by directly treating the metal or its oxide with a chelating reagent. This greatly simplifies and speeds up the analysis. Therefore, it is extremely convenient to use metal chelates to obtain new ligands capable of producing strong volatile chelates with metals:

It should be noted that the detection limit for well-chromatographed chelates is several picograms and depends on the sensitivity of the detector. For chelates that do not chromatograph well, the detection limit is a few micrograms.

Relationship between the volatility of chelates and the structure of their molecules. For the targeted synthesis of volatile metal chelates, attempts were made to theoretically generalize the accumulated experimental material based on their chromatographic behavior.

Attempts to relate the configuration of the complex molecule with volatility or chromatography have not yet yielded unambiguous results. Volatile and well-chromatographed complexes are known that have tetrahedral, octahedral and square planar configurations. At the same time, many complexes of the same configuration are low volatile or difficult to chromatograph.

Both stable and labile volatile complexes are known, i.e., the question of the role of the kinetic stability of the complexes is not entirely clear.

Most known volatile complexes contain either six-membered rings with a delocalized double bond or four-membered rings with a delocalized double bond. Volatile chelates with a five-membered ring are practically unknown.

It has now been established that the structure of the complex affects its chromatographic retention. The retention of isostructural β-diketonates of different metals with the same ligand increases with increasing metal ion radius. However, the retention of structurally similar chelates of various metals is largely determined by the ligand and the liquid phase used. If there are small differences in the ionic radii of the metals, it is possible to change the order in which the chelates leave the column by selecting the liquid phase. Thus, when chromatography of nickel and copper β-ketoamines on a column with pQF-I, the nickel chelate leaves the column before the copper chelate. On a column with apiezone L, these chelates come out simultaneously, and on a column with polycarboranesiloxane, copper beta-ketoamine comes out before the corresponding nickel chelate. Often, many experimentally observed facts can only be explained by the specific interaction of metal chelate molecules with the liquid phase, but the nature of this interaction in many cases is not clear enough.

Mechanism of chelate retention. A number of studies have investigated the retention mechanism of metal chelates. It was found that the retention of a number of chelates is determined by three main factors: 1) dissolution in the liquid phase; 2) adsorption on the surface of the solid phase; 3) adsorption of the chelate on the surface of the liquid phase.

Gas chromatography with modified mobile phase. Two methods have been developed for the separation of metal complexes using gas chromatography with a modified mobile phase.

One of them uses a carrier containing ligand lars. The decomposition and sorption of metal β-diketonates in columns is reduced by adding a small amount of vapor of the corresponding β-diketone to the carrier basin. The thermodynamic characteristics of the system do not change. The improvement in chromatograms is explained by the suppression of dissociation of chelates in the liquid phase in the presence of an excess of free β-diketone. Under such conditions, it was possible to completely separate a number of neighboring chelates in the D.I. table. Mendeleev REE. This method has not yet been extended to other volatile metal complexes, such as diethyl dithiocarbamates, dialkyldithiophosphates, and dialkyldithiophosphinates.

The second method proposes using three high pressures as a mobile phase of freon in a supercritical state. In this case, the volatility of many metal complexes increases due to changes in the thermodynamic parameters of the system. The method has not found wide practical application due to the relative complexity of the equipment.

It should be noted that great difficulties in gas chromatography of metal chelates are associated with an anomaly in the behavior of many of them in the chromatographic column, and the anomalous behavior increases sharply when going to very small quantities.

Diagnostics of oil-filled equipment during operation.

Periodic monitoring of the condition of the transformer under operating voltage.

First of all, the insulation condition of transformer equipment can be assessed by checking the quality of transformer oil. To do this, its physicochemical characteristics are periodically measured and compared with acceptable ones (OiNIE). Analysis of the characteristics of the oil reveals its electrical strength as a dielectric, the tightness of the structure in terms of moisture content and total gas content (for sealed structures), the presence in the oil of aging products of paper-oil insulation, products of oxidation and decomposition of the oil, and much more.

Periodic analysis of oil samples and its physical and chemical analysis make it possible to monitor the dynamics of the insulation aging process and timely take the necessary measures to maintain its performance. Therefore, the results obtained must first of all be compared with previous measurements and with the maximum permissible values. Oil sampling, its frequency and evaluation criteria are established by factory instructions for the types of equipment, the scope and standards for testing electrical equipment, guidelines for the operation of transformer oils, or are determined by the technical manager of the power enterprise, taking into account the specific conditions and technical condition of the equipment.

In domestic practice, a set of indicators characterizing the quality of oil is divided into “abbreviated” and “full” analysis. The most important characteristics of the oil are: breakdown voltage, acid number, flash point (with regular chromatographic analysis of the oil, this characteristic loses its relevance), moisture content, dielectric loss tangent, presence of mechanical impurities, content of antioxidant additive - IONOL, aqueous extract reaction. The standards for these parameters adopted in our country are based on many years of practical experience and are enshrined in OiNIE.

To diagnose the condition of a transformer, the most important role is played by the physicochemical analysis of transformer oil, and first of all, chromatographic oil analysis (CHARG) for the presence of seven dissolved gases and furan compounds.

Chromatographic analysis of gases.

Chromatographic analysis of gases dissolved in transformer oil is now widely used in all developed countries as an effective means of early diagnosis of slowly developing defects. There are international and domestic standards both for the HARG procedure and for the interpretation of analysis results, which are quite close.

HARG includes several stages:

Taking an oil sample into an oil sampling device (syringe),

Transportation and proper storage of the sample,

Release of dissolved gases using a special technique,

Determination of gas content in a gas analyzer (chromatograph),

Diagnosis of a defect based on the composition of gases and their growth rate.

Chromatographic analysis of gases dissolved in transformer oil is carried out in special laboratories and is a highly professional task. For a more detailed study of the issue, we can recommend the work or other special publications.

The first step of CARG is the release of gases from the oil. The most common method is the equilibrium release of gases in a syringe. To do this, oil and carrier gas (helium or argon) are taken into a syringe with a capacity of 20 ml in certain ratios established by the accepted methodology, then the resulting mixture is bubbled. In this case, a gas exchange process occurs and part of the gases from the oil passes into gas in accordance with known solubility coefficients. The resulting mixture of carrier gas and gases dissolved in the oil is analyzed for its quantitative composition in special devices - chromatographs.

Chromatographs use the gas adsorption method for separating the analyzed gas mixture in special columns (Fig. 3) filled with an adsorbent (porous substances that are “molecular sieves”). Differences in the physicochemical properties of the individual gases of the mixture lead to different speeds of their movement along the separation column. Therefore, they will appear at the column output at different times:

C 2 H 2, C 2 H 4, C 2 H 6 C 2 H 4 C 2 H 2

C2H6

mixture of gases separated gases

Figure 3 - Principle of gas separation in a chromatograph column

Based on the properties of gases, their quantitative concentrations are determined by special devices called detectors and recorded in the form of chromatograms on a computer display. The results are processed on a computer using special programs, analyzed and stored in a database for oil-filled equipment.

Scheduled oil sampling for CARG at intervals of 1 time in 6 months in most cases allows:

Monitor the development of defects

Anticipate damage not detected by traditional methods,

Determine the approximate nature of the damage - discharges, hot spot (formation of closed current loops through coupling bolts,

Detect defects in the tap changer contacts, defects in intersheet insulation, overheating of solid insulation, partial discharges due to under-impregnation of the insulation, its excessive moisture, defects in potential connections of shielding rings and other parts with the formation of floating potential and sparking, etc.

However, it should not be assumed that chromatography detects all types of defects. There are certain types of defects that develop so rapidly that taking oil samples at intervals of several months does not allow timely detection of their development (instantly developing arc flashovers, turn and intercoil short circuits, creeping discharges, sudden breakdowns of the main insulation or channels due to the concentration of impurities, moisture or foreign objects left during repairs).

ABOUT main gases(the gas with the highest, relatively limiting, concentration is considered the main gas), according to chromatography experience, the most characteristic of various defects are:

H 2 (hydrogen) – electrical defects (low-energy partial discharges, spark arc discharges, hot spot),

C 2 H 2 (acetylene) – high energy discharges (sparking, arc) heating above 700 °C,

CH 4 (methane) – heating of oil and insulation in the temperature range of 250-400°C (transformer overload or cooling system defect), low-energy partial discharges,

C 2 H 6 (ethane) – thermal heating of oil and B-M insulation in the range of more than 300 ° C,

C 2 H 4 (ethylene) - high-temperature (more than 600°C) heating of oil and B-M insulation,

CO (carbon monoxide) – aging and wetting of oil (or solid insulation), overheating of insulation throughout the entire mass,

CO 2 (carbon dioxide) – heating and aging of solid insulation (paper, cardboard).

For illustration (Fig. 4), below is a qualitative diagram of the dynamics of gases contained in transformer oil, depending on the temperature of the “hot spot”

Figure 4 - Diagram of gas dynamics in the presence of a “hot spot”

Table 1, as an example, shows the limit values of gases of normally operating transformers accepted both in Russia and abroad.

Table 1 - Limit gas concentrations for power transformers

* For transformers with on-load tap-changers that have a common expander according to the experience of JSC Lenenergo.

To diagnose the condition of oil-filled equipment based on the results of HARG, 3 criteria are used:

1. Criterion for exceeding boundary (limit) concentrations. Limit concentrations are determined by statistical processing of the results of HARG of normally operating transformers in the power system according to voltage classes, types of oil protection, and service life. In the absence of such data, they are guided by the limit concentrations given in RD 153-34.46.302-00 (first line of Table 1).

2. Gas growth rate criterion used to detect the rising trend of gases. An increase in the growth rate of more than 10% per month is considered an “alarm signal” and the transformer is placed on frequent monitoring, even if the concentrations have not yet exceeded the limit values. In this case, it is necessary to carefully analyze the operating mode of the equipment (increasing load, oil and atmosphere temperatures, operating voltage, external short circuits, etc.) One should also take into account the possibility of random error, especially for hydrogen and CO, due to gas loss during sampling and transportation of the sample. Therefore, first of all, you need to repeat the oil sample and make sure that the result is stable (reliable).

3. Criteria for gas vapor ratios allows , First of all, divide into electrical defects when C 2 H 2 / C 2 H 4 is more than 0.1(additionally CH 4 /H 2 less than 1) and thermal defects C 2 H 2 / C 2 H 4 much less than 0.1(confirmation of this fact is CH 4 /H 2 more than 1). The ratio C 2 H 4 /C 2 H 6 characterizes the temperature of the hot spot. The gas ratio criterion is used only if at least one gas included in the ratio exceeds the limit concentration. The CO 2 /CO ratio is used to judge whether solid insulation is involved in a defect (if there are signs of heating or discharge). When CO 2 /CO exceeds ten, cellulose overheats. A ratio less than three indicates cellulose aging under the influence of electrical defects. The issues of clarifying the types of defect are set out in more detail in RD 153-34.46.302-00.

In Fig. Figure 5 shows a structural and logical diagram of the process of analyzing the results of HARG and making a decision. The type of developing defect can be roughly determined graphically from the “portrait” of the main gases. The graphs are constructed as follows (Fig. 6 – fig.16):

- based on the results of HARG, the relative concentrations (a i) of gases (relative to the boundary ones) are calculated,

- the component with the highest relative concentration (a max) is taken as the main gas,

- determine the value for hydrocarbon gases and hydrogen,

Five equal segments are laid out along the X-axis and the resulting points are designated in the following sequence: H2, CH4, C2H6, C2H4, C2H2,

On the Y axis the corresponding value of the ratio (a i)/ (a max) is plotted for each gas,

The resulting points are connected by straight lines,

The constructed graph is compared with “standard portraits” and the closest one is found.

1 – sampling according to schedule

2- accelerated selection

Figure 5 - Structural and logical diagram of diagnostics based on the results of CARG.

The figures (Fig. 6 – Fig. 9) show “graphic portraits” based on the results of HARG, corresponding to electrical defects caused by discharges (hydrogen predominates).

The figures (Fig. 10 - Fig. 12) show “graphic portraits” corresponding to thermal defects in the range of average temperatures ( the predominant gas is methane), moving to the Czech Republic .


Figure 10. Thermal defect	Figure 11. Thermal defect

The figures (Fig. 13 – Fig. 15) show “graphic portraits” of gases corresponding to thermal defects in the high temperature range ( the predominant gas is ethylene).


Figure 12. Thermal defect	Figure 13. High temperature heating

Figure 14. High temperature heating	Figure 15 - High temperature heating turning into an arc

Let's look at an example of determining a defect based on the results of CARG. When constructing the graph, the absence of operational factors contributing to the growth of gases dissolved in oil was taken into account (clause 3.2 of the RD).

Limit concentrations of RD gases dissolved in oil.

In the transformer TRDTSN-63000/110, according to the results of the ARG, the following concentrations of gases dissolved in the oil were obtained:

H 2 = 0.004% vol, CH 4 = 0.084% vol, C 2 H 2 = 0% vol, C 2 H 4 = 0.02% vol, C 2 H 6 = 0.011% vol,

CO = 0.05% vol., CO 2 = 0.48% vol.

1. Determine the relative concentrations (a i) for each gas:

a h2 = 0.004/0.01=0.4, and CH4 = 0.084/0.01=8.4, and C2H2 = 0, and C2H4 = 0.02/0.01=2.0,

and C2H6 = 0.011/0.005=2.2

2. Based on the obtained relative concentrations, we determine the main gas:

8.4 = a CH4 > a C2H6 > a C2P4 > a H2 , those. main gas - methane

3. Determine the values of the segments along the Y axis for each gas:

CH 4 = 1, H 2 = 0.4/8.4 = 0.05, C 2 H 4 = 2/8.4 = 0.24, C 2 H 2 = 0, C 2 H 6 = 2.2/8.4 = 0.26

4. We build a graph (Fig. 16).

5. For the main gas CH 4 we find a graph similar to the plotted graph (Fig. 10). When comparing, we conclude: in the transformer, according to the ARG data, a thermal defect is predicted in the range of average temperatures.

6. To decide whether solid insulation is affected by a defect, we determine the ratio of CO 2 /CO concentrations:

CO 2 /CO = 0.48/0.05 = 9.6< 13 (см. П.5.3.РД), следовательно, твердая изоляция дефектом не затронута.

7. To check the diagnosis (this check is not given in subsequent examples), we determine the defect predicted in the transformer according to the ratio criterion (clause 5.2, Table 3 RD):

We calculate the ratio of gas concentrations:

Based on the data obtained, a defect of a thermal nature is predicted - “thermal defect in the range of average temperatures (300-700) ° C.”

Since CO 2 /CO = 0.16/0.02 = 8< 13 (см. П.5.3.РД), делаем вывод, что дефект не затрагивает твердую изоляцию и относится к группе 1 (п.2.1).

Thus, we obtained a coincidence of the nature of the predicted defect, determined graphically and according to the gas ratio criterion.

Figure 16 - Graph of a thermal defect in the average temperature range caused by burnt contacts of the selector

Physicochemical analysis of oil. The quality of transformer oil is assessed by comparing test results with standard values depending on the type, type and voltage class of electrical equipment, as well as their dynamics. Standard values of oil quality indicators and test frequency are regulated by the current OiNIE and “Methodological guidelines for the operation of transformer oils” (RD 34.43.105-89). The peculiarity of the new standards is: firstly, that FHAM is placed at the forefront when assessing the condition of oil-filled equipment, secondly, highlighting two areas of oil operation:

- area of "normal oil condition", when the oil quality condition guarantees reliable operation of electrical equipment,

- "risk" area when the deterioration of even one indicator of oil quality leads to a decrease in reliability and frequent and extended monitoring is required to predict service life or take special measures to restore its operational properties or replace it.

Oil control begins with a visual inspection of the oil: its color, presence of contamination, and transparency are analyzed. Fresh oil is usually light yellow in color, while its dark color indicates aging and possible overheating during operation. Based on the results of the visual inspection, a decision is made to conduct additional tests:

Electric strength transformer oil 40-70 kV is determined according to GOST 6581-75 in a standard arrester using AIM-80, AIM-90 devices and, as a rule, does not cause difficulties. Electrical strength is the main insulating characteristic of oil, which determines its performance. Electrical strength decreases when the oil is significantly moistened (water in the form of an emulsion) and contaminated with mechanical impurities, especially at high humidity.

The most significant decrease in electrical strength with increasing moisture content is observed at a water content of more than 25-30 g/t. Mechanical impurities reduce the electrical strength depending on their fractional composition and their conductivity. The most noticeable reduction in strength occurs at particle sizes greater than 100 microns.

Quantitative water content. Water in oil, as already noted, can be in the following states: bound, dissolved, emulsified, layered (precipitated). Bound water is determined by the fractional composition of the oil and impurities, is in solvated form and, as a rule, is not detected by conventional methods of oil analysis.

Until now, oil moisture in power systems has been determined mainly by the calcium hydrite method using a PVN device in accordance with GOST 7822-75. The principle is based on the reaction of calcium hydride with water during which hydrogen is released:

CaH 2 + H 2 O = Ca(OH) 2 + 2H 2

The amount of hydrogen gas released is used to calculate the content of water dissolved in the oil.

In recent years, methods for determining water have been introduced according to the method of publication IEC 814 (coulometric titration in Karl Fischer reagent). The moisture content of liquid dielectrics using this method is determined by the amount of electricity spent on generating iodine that reacted with water

Transformer oil moisture meter VTM-2, produced by Angarsk OKBA, implements the coulometric method of measuring moisture. The essence of the method is the absorption of moisture by the sorbent film from the flow of carrier gas (air) flowing through the oil and extracting moisture from the oil. The moisture absorbed by the film undergoes electrolysis and the moisture content is determined by the amount of electricity.

VNIIE has developed a method for chromatographic determination of the moisture content of transformer oil using gas chromatographs. According to the VNIIE method, a small sample of oil (25-100 µl) is introduced into the evaporator. The evaporator temperature is about 180 degrees, so all the water present in the oil turns into a gaseous state and, together with the released gases, enters the chromatographic column in which the gases are separated. The thermal conductivity detector then records the amount of water.

Acid number (KOH) determined according to GOST 5985-79 by titration with an alcohol solution. KOH is the amount of potassium hydroxide in milligrams required to neutralize the free acids in 1 g of oil. The acid number of an oil exceeding 0.15 mg/g is a sign of its aging and oxidation (the content of acidic compounds in it) and serves as the basis for assessing the condition of the oil: the need to replace silica gel in thermosiphon (adsorption) filters, oil regeneration, checking the antioxidant content ionol (agidol) additives in oil. The higher the acid number of the oil, the higher its conductivity and dielectric losses, as a rule. The acid number should not exceed 0.15-0.25 mg/g.

Dielectric loss tangent oil characterizes the properties of transformer oil as a dielectric. Dielectric losses of fresh oil characterize its quality and degree of purification, and in operation - the degree of contamination and aging of the oil (increased electrical conductivity, formation of colloidal formations, soluble organometallic compounds (soaps), resinous substances). Deterioration of dielectric properties (increase in tgd m) leads to a decrease in the insulation characteristics of the transformer as a whole.

To determine tgd m, oil is poured into a special vessel (according to GOST 6581-75) with cylindrical or flat electrodes. Oil sampling is carried out in accordance with the requirements of GOST 6433.5-84. The measurement is made using an AC bridge P5026 or another type.

tgd m is normalized at temperatures of 20 o C and 90 o C. In operation, it is advisable to measure its value at a temperature of 70 o C both during a rise and fall in temperature. The “hysteretic” nature of the temperature dependence of tgd m is a sign of deep aging of the oil (a decrease in tg d m at a temperature of 70 o C during a temperature decline after prolonged exposure at 90-100 o C can occur either due to coagulation and sedimentation, or due to strong moisture oils).

Water-soluble acids and alkalis contained in the oil (more than 0.014 mg/g) indicate low quality oil. They can form during the oil production process if the production technology is violated, as well as as a result of oxidation during operation. These acids cause metal corrosion and contribute to the aging of solid insulation. For the qualitative detection of water-soluble acids (WSA), according to GOST 6307-75, a 0.02% aqueous solution of methyl orange is used, and for the detection of alkalis and soaps, a 1% alcohol solution of phenolphthalein is used. These reagents change color in the presence of undesirable components. The determination of VRC in oil consists of extracting them from the test oil with distilled water and determining the reaction of the aqueous extract with a pH meter.

Oil flash point in a closed crucible characterizes the degree of evaporation of the oil and its saturation with light hydrocarbons. For commercial oils, the flash point should be in the range of 130-150°C. The standards allow a reduction in flash point by no more than 5°C, compared to previous tests.

Determination of antioxidant additive content(IONOL). In the presence of ionol, the process of thermal-oxidative aging of the oil occurs relatively slowly and the oil has indicators that meet the standards for a long time. During oil operation, there is a process of continuous consumption of ionol and when it decreases below a certain limit (0.1%), the process of intensive aging of the oil begins, accompanied by the formation of sludge, an increase in the acid number, and a deterioration in the performance characteristics of the oil. Replacing silica gel in thermosiphon filters usually gives only short-term results. The determination of the content of the ionol additive is currently carried out by thin-layer chromatography on special plates (RD 34.43.105-89), by liquid chromatography on liquid chromatographs (RD 34.43.208-95), on gas chromatographs using the VNIIE method, or by IR spectroscopy methods. In fresh commercial oils, the ionol content is 0.25-0.3%. When it decreases during operation below 0.1%, oil regeneration and the addition of ionol are required.

Quantitative content of mechanical impurities. The appearance of mechanical impurities in the oil indicates either gross defects in the production of insulation, or the presence of abrasion and delamination of materials during operation. Mechanical impurities lead to a strong decrease in the electrical strength of the oil. Therefore, their presence is determined first visually and, if necessary, quantitatively. Quantitative analysis determines the number of particles and distributes them according to size ranges. This information allows you to determine the oil purity class according to GOST 17216-2001. For the quantitative determination of mechanical impurities, devices AZZH-975 (Samara), PKZH-904 (Saratov), GRAN-152 (Tekhnopribor) are used. In some cases, along with the quantitative determination of impurities, it is useful to study the qualitative composition of impurities under a microscope to find the source of their origin. For example, the presence of metal particles indicates destruction of the transformer circulation pumps.

The main indicators of the quality of operating oil are given in table. 2

Table 2 - Areas of operation (condition) of transformer oil

Oil quality indicator (basic)	“Normal oil condition” area	"Risk" area
from	before	from	before
Electric strength Upr, kV Equipment. up to 35 kV Up to 150 kV 220-500 kV		and higher		and below
Acid number (KOH), in % Up to 220 kV Above 220 kV	0,02 0,01	0,1 0,1	0,1	0,25
Moisture content in G/T With oil protection Without protection	-
Mechanical impurities in g/t (purity class) Up to 220 kV Above 220 kV	Absent 10 (10)	(12) 20 (11)	Absent 20(11)	(13) 30 (12)
Loss tangent at 90 degrees, % Up to 220 kV Above 220 kV	0,7
“Ionol” content, %	0,18	0,1	Less than 0.1

Chromatographic methods of analysis: gas chromatography method. Gas chromatography

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