Mettler-Toledo International Inc. (MTD) Earnings Call Transcript & Summary

Ladies and gentlemen, welcome to this Mettler-Toledo webinar on Evolved Gas Analysis combined to Thermogravimetric Analysis. My name is Thomas Oberholzer, and I'm the Product Manager for Material Catheterization and Thermal Analysis and organizer of this webinar. I'm pleased to be joined by our expert, Dr. Angela Hammer from the Thermal Analysis Market Support Group. Angela is one of our most versatile specialists, she's experienced in every technique. Angela and I are both located at the headquarter of Mettler-Toledo in Greifensee, Switzerland. Let me briefly introduce Angela to you. After studying chemistry at the University of Clausthal in the northern part of Germany, Angela moved to the Swiss Federal Institute of Technology in Zurich, Switzerland, where she majored PhD in chemistry. This on the development of immobilized components for the use of iron selective electrodes based on polyurethane membranes. After the PhD, Angela accepted a position in reconstruction chemistry, where she worked in a big company as an analytical chemist and learned about thermal analysis later on. She decided to continue her career here at Mettler-Toledo and to move to our market support group. In this role, she has now collected as an application specialists collected more than 15 years of experience. Angela will be happy to answer your questions during or after the presentation, and we hope you take the opportunity to discuss your thermal analysis or evolve gas analysis questions with our expert.  To ask questions, we would kindly ask you to use the chat as I muted your lines. The main part of the webinar will be a prerecorded presentation. It will take quite long. We estimate about 60 minutes without explanations of our expert. So I hope you have a bit of time. As the content is quite compact, we made the experience that we have to interrupt the presentation. This will be done, and Angela will give you some additional background information. And of course, this will give you the opportunity to ask questions, and she will then answer. So then we will now start the presentation enjoy.

Ladies and gentlemen, welcome to the Mettler-Toledo webinar on Evolved Gas Analysis, or EGA for short. In the broader definition, evolved gas analysis has to do with the investigation of the nature of gaseous products released by a substance as it is heated. This can be done using many different types of techniques and equipment. More specifically, this webinar describes evolved gas analysis as it is performed in thermal analysis, namely by coupling a thermogravimetric analyzer or TGA for short, to a suitable gas analysis system. First, I would like to explain the principles involved in evolved gas analysis and show how this capability can easily be added to an existing Mettler-Toledo TGA DSC instrument. I will then go on to describe the individual benefits and limitations of the 4 EGA techniques, namely MS, mass spectroscopy; FTIR, Fourier Transform Infrared Spectrometer; GCMS, Gas chromatography/Mass spectroscopy; or Micro GC/MS, Micro gas chromatography/mass spectroscopy. Finally, I will illustrate the use of each TGA EGA system by means of several application examples. This example, an unknown specimen was heated to about 1,400 degrees Celsius in a thermogravimetric analyzer. The TGA curve displays several mass loss steps that can be quantitatively determined. If the sample is a pure substance of defined molecular weight, some information about decomposition products can be obtained from stoichiometric considerations. But in general, TGA is not an identification technique. Additional information about the sample can, however, be obtained by coupling the TGA to a gas analyzer. TGA-EGA allows you to investigate thermal and oxidative decomposition processes, evaporation and sublimation processes, curing processes and absorption and desorption behavior. TGA-EGA is also an excellent identification tool and is often used to determine solvents, additives or individual compounds in matrix materials. TGA is a technique that quantitatively measures the mass change of a substance test specimen as it is heated or held isothermally under a controlled atmosphere. To acquire more information about the sample, a Mettler-Toledo TGA or TGADSC can be coupled to a suitable gas analyzer such as MS, FTIR, GCMS or Micro GC/MS.  The schematic diagram shows the general setup of a TGA system. Starting from the left, the purge gas sweeps decomposition gases and vapors from the TGA into the gas analyzer through a heated transfer line. In a TGAMS or FTIR experiment, evolved gases are analyzed online. Or in other words, while the TGA experiment is running. In GCMS, samples are taken at predefined temperatures during the TGA measurement and stored in a storage interface for a subsequent analysis. PGA Micro GC/MS is a quasi-online technique because the analysis of a gas sample is very fast, taking only about 2 to 3 minutes. This enables several Micro GC/MS injections to be performed during the TGA experiment. The schematic diagram shows the operating principle of a quadruple mass spectrometry of the type used for TGA MS measurements.  When the purge gas with the volatile products from the TGA reaches the mass spectrometer through the transfer line, only about 1% is allowed to enter the instrument. The rest is removed by a pump. This is necessary because the mass spectrometer operates at high vacuum, and the vacuum would otherwise collapse. However, the small amount of sample is not a problem because a mass spectrometer is extremely sensitive. The molecules that arrive in the ionization chamber are bombarded by an energetic electron beam. This causes the molecules to fragment to smaller positively charged fragment ions, most of which are singly charged. The ions are then accelerated into a chamber where they are separated according to their master charge ratio through a combination of electrostatic and electromagnetic fields. The mass spectrometer detector system measures either the entire mass spectrum or continuously monitors the intensity of a number of characteristic fragment ions. The ions formed are directly related to the structure of the molecule. Interpretation of the masses of the fragment ions and their intensities allows compounds to be identified. Alternatively, the measured data can be compared with reference data in mass spectral libraries of known compound. This slide summarizes the advantages and limitations of mass spectrometry. In TGA EGA applications, mass spectrometry is primarily a qualitative technique used for the identification of gaseous molecules. -- semi-quantitative measurements are also possible with suitable calibration. The technique is extremely sensitive. This means that either only very small quantities of sample are needed or that very low concentrations of evolved gases can be detected. The measurement of the mass spectrum is extremely fast so that ions of all masses within the mass range of the detector are recorded almost instantaneously. This means that many different fragment ions can be simultaneously monitored as a function of time. This allows overlapping mass loss effects in the TGA to be interpreted. The decomposition products are measured almost immediately as soon as they are encouraged from the TGA furnace. The timescale of the MS data corresponds exactly to that of the weight loss curve. Since the molecules are analyzed as different molecular ion fragments, a certain amount of experience and interpretation as well as knowledge about the sample is required to elucidate the original structure nature of the sample. Furthermore, some fragment ions have the same master charge ratio and cannot be distinguished. For example, both carbon monoxide and nitrogen have the same molecular mass of 28. Finally, decomposition products that are not volatile are not transferred into the spectrometer and they're not detected. The second identification technique used for TGA EGA is Fourier Transform Infrared Spectroscopy. In a TGA-FTIR combination, the entire effluent from the TGA passes through a heated capillary into the sample cell of the FDIR spectrometer. Spectra are recorded at a rapid rate, typically 1 per second. So the time delay between sample decomposition in the TGA and the measurement of the corresponding spectrum is more or less negligible. FTIR spectroscopy is based on the absorption of electromagnetic radiation by molecules in the mid-infrared spectral region from 4,000 to 400 wave numbers. The energy in this spectral range is low compared with that used in mass spectrometry, so that no ionization or fragmentation occurs. The slide shows the different modes of vibration of a group of atoms. The modes comprise the energetically stronger symmetrical and anti-symmetrical stretching vibrations and the weaker scissoring rocking wagging and twisting vibrations. The molecules absorb infrared energy at frequencies that depend on the structure of the molecule. The absorption of energy causes the molecule or certain parts of the molecule, the so-called functional groups to vibrate at the same frequencies at which they absorb the energy. The absorption frequencies are unique for a particular molecule and can therefore be used to characterize or identify a substance or the class of substance through interpretation or the use of spectrum libraries. This slide summarizes the advantages and limitations of FTIR. As in mass spectrometry, measurements are performed very rapidly so that real-time spectra of the decomposition products are obtained. Spectral libraries are available for comparing the measured Spectra with the reference spectra of known molecules. FTIR is most useful in providing information about the presence or absence of specific functional groups, but unlike MS, does not provide detailed information or proof of molecular formula or structure. Since FTIR is a less sensitive technique compared to MS, larger sample quantities are often required. FTIR cannot detect symmetrical diatomic molecules such as oxygen and nitrogen as they are not infrared active. The technique is also limited to volatile decomposition products and may not be adequate for the identification of different molecules containing the same functional groups or overlapping absorption bands. FTIR and MS are mainly used when the composition of the decomposition gases is dominated by just a few gases and the other decomposition gases only occur at low concentrations. If the composition of the decomposition gases consists of a large number of different gases than the combination of a TGA with GCMS or a Micro GC/MS is recommended. This schematic describes the separation mechanism by GC. A sample containing 3 different species is injected onto the GC injection unit. The components are the carrier gas usually helium to the column. Once in the column, the mixture of compounds is separated into the various components. The column is typically heated from 40 or 50 degrees Celsius to 300 degrees Celsius at a rate of 5 to 10 degrees Celsius per minute. The separation of compounds is based on the different interaction of the compounds with the stationary phase. The stronger the interaction is, the longer the compound takes to migrate through the column. The retention time refers to the time it takes a gas species to pass through the column. Here, we can clearly see the different retention times of the 3 compounds. The amount of each compound is then measured by the detector. When coupled to an MS detector, the individual compounds can be identified with the help of a spectral database. Alternatively, GC can be combined with several different detectors such as a thermal conductivity detector or TCD or a flame ionization detector, FID. TCD measures differences in thermal conductivity between the pure carrier gas and the gas from the column. In an FID detector, combustion of most organic compounds and a hydrogen air flame produces ions, which are collected and converted into a current. These detectors have the disadvantage that evolved gases can be identified based solely on their retention times.  Mettler-Toledo offers 2 types of chromatographic systems, GCMS and Micro GC/MS. These can be hyphenated to a TGA or TGA DSC instrument. The first option I want to discuss is TGA coupled to a GCMS. In such a system, gases injected into the GC are separated and stored at the relevant temperatures for subsequent offline analysis. Typically, 1 GC analysis takes about 45 minutes to 1 hour. The storage interface consists of a series of valves and loops in the storage mode, the gas flow from the TGA passes through the next loop to be filled to the outlet of the storage interface. When the desired TGA program temperature reaches the temperature chosen for filling the loop, the inlet and outlet sides of the loop are closed and the gas flow from the TGA is switched to the next loop. This allows gas samples to be collected at up to a maximum of 16 different TGA temperatures. The samples correspond to the composition of the decomposition gases at each particular temperature. As soon as the storage loops are filled with gas samples, the storage interface switches automatically from the storage to the injection mode. In this mode, the gas samples are transferred by the carrier gas one by one through the second transfer line into the GCMS and analyzed with respect to their composition.  At the exit of the GC, the MS continuously records the mass spectra. If each recorded mass spectrum is integrated and this integral is plotted as a function of time, the so-called total ion current, or TIC is obtained. Each peak on the TIC curve corresponds to a particular species. The mass spectrum associated with each peak unequivocally characterizes the substance in question. Identification is achieved by comparing the measured mass spectrum with mass spectra and a database. So-called emission profiles of a substance can be created from the mass spectrum of a particular TIC peak by plotting the intensity of the main fragment ion M over Z of the substance as a function of temperature. An example of emission profiles obtained in the storage mode is shown in the lower part. The normalized DGA curve of the sample is shown in black, and emission profiles of some of the evolved compounds in color. The individual data points correspond to the individual loop injections. In this example, compound A evolves at lower temperatures between 300 degrees Celsius and 400 degrees Celsius while compounds, B and C evolve mainly during the main decomposition step between 350 degrees Celsius and 550 degrees Celsius. This slide summarizes the advantages and limitations of GCMS. A separation technique like GCMS is ideal for the analysis of complex gas mixtures where several unknown gaseous products are released simultaneously. After suitable calibration, the composition of the decomposition gases can also be determined quantitatively. The transfer line of the storage interface is easily removed, and the GCMS can be used as a stand-alone instrument for the analysis of liquids. In TGA GCMS, samples are mostly analyzed offline. Each gas sample takes about 45 minutes to analyze, which can result in lengthy experiments depending on the number of samples stored in the storage interface. In addition, a preliminary TGA experiment is needed to define the relevant sample collection temperatures, so-called permanent and light gases are often not separated from the TGA purge gas -- and finally, as with MS and FTIR, nonvolatile species are not transferred into the storage interface and can, therefore, not be detected...

So let us make a short stop here. And if you have any questions so far, we would kindly ask you to write down your question in the chat. So in the meantime, let me give you some additional information regarding the combination of the TGA to the GCMS via the storage interface IST60. So on the bottom of the slide, you see 2 pictures. We have 2 possibilities to connect the TGA to the IST60. On the right side, we see a direct collection. And on the left side, we see a connection using a small PTFE tubing. So why do we connect this PTFE tubing to prevent contamination of the transfer lines of the storage interface by larger molecules. So as we heard before, 2 large molecules will not be possible to end last by GCMS. And to prevent that the condensed or CantaMia some parts. We use this tubing. So the heavy molecules would condense in this PTFE tubing. And when you make measurements, usually, we exchanged this tubing for every measurement so that we do not have an effect that we have for a new sample experiment, we somehow create peaks from the former sample that could still remain here in this tubing. So the tubing is some kind of spare part and we usually use it to prevent the contamination and we exchange it every -- for every new sample. I see there are no questions in the chat so far. I suggest you can use the chat anytime. We will interrupt the presentation one more time, and so you have a chance, please take your chance if you have any questions. So I suggest we continue with...

The working principle of Micro GC is similar to that of conventional GC, except that the different components are miniaturized in Micro GC and form a so-called module. As in GC, different separating columns are available for the micro GC, depending on the compounds that have to be detected. Micro GC therefore, consists of several modules with different columns through which the gas is being analyzed, flow in parallel. The time needed to record a chromatogram is much shorter, typically 3 minutes due to the comparatively short columns used. Each Micro GC module is equipped with a thermal conductivity detector consisting of 2 identical measuring cells, one for the carrier gas and the other for the analyte gas from the column. Depending on the composition of the measurement gas, the analyte and the carrier gas have different thermal conductivities. This results in an electrical signal proportional to the concentration of the analyte producing a peak in the chromatogram with separating columns that allow larger molecules to be detected, the identification of gases based on retention time is difficult because of the large number of separable gases and MS detector is therefore, recommended for such columns besides the TCD detector. As shown in the lower schematic, a TGA is coupled to a micro GC or Micro GC/MS by way of a heated transfer line. The Micro GC offered by Mettler-Toledo can be equipped with up to 3 different modules. They allow about 95% of the gases currently detectable with Micro GC to be separated.  This slide summarizes the advantages and limitations of Micro GC/MS. Micro GC is a quasi-online technique, which provides fast, precise gas analysis in just 2 to 3 minutes. Identification of unknown products can be achieved by coupling on Micro GC module to an MS detector. A maximum of 3 modules can be used simultaneously, semi-quantitative measurements are possible with suitable calibration. However, the number of compounds that can be separated with a particular column is limited. Micro GC, therefore, usually consists of several modules with different columns through which the gas is being analyzed flow in parallel. So one could ask which separation technique is best for my problem, TGA GCMS or TGA Micro GC/MS. This slide illustrates the application range of TGA GCMS and TGA Micro GC/MS, in which gas compounds have been classified according to their boiling point. TGA-GCMS is ideal for the detection of medium light, medium and heavy compounds. This includes solvents, such as methanol, C31 to C18 hydrocarbons, phenols, et cetera. Micro GC with a molecular SIV column and a TCD detector is the best choice for the detection of permanent and light gases. Small molecules such as nitrogen, hydrogen, oxygen, methane and carbon monoxide can be identified using one module, a second module is needed for carbon dioxide, water, light solvents and hydrocarbons up to C3 and a third module for nitrogen oxides and hydrocarbons up to C8. If a column for C4 to C8 hydrocarbons is used in the micro GC, the identification of the particular compound based on its retention time is difficult. MS detection is recommended for such columns in addition to the thermal conductivity detector used in the micro DC.  Evolved gas analysis has numerous potential applications and can be used in practically all industries. The slide summarizes the main industries and applications. The industry's range from the automotive field to chemicals, plastics and pharmaceuticals. The applications have to do with volatiles, additives and decomposition products. I would now like to present several different application examples that demonstrate the analytical power and versatility of evolved gas analysis. The first application illustrates the use of TGA MS to investigate the decomposition of calcium oxalate monohydrate. The TGA curve shows that the substance decomposes in 3 distinct steps. The decomposition was investigated by monitoring the MOZ 18 28 and 44 ions that correspond to water, carbon monoxide and carbon dioxide. The results confirm that the first step corresponds to the loss of water of crystallization. The second step to the release of carbon monoxide from the anhydrous calcium oxalate and the third step to the liberation of carbon dioxide from the calcium carbonate formed in the second reaction step. Stoichiometrically, one mole of calcium oxalate monohydrate produces 1 mole each of water, carbon monoxide and carbon dioxide. The MOZ 44 curve, however, shows that a small amount of carbon dioxide is also formed in the second weight loss step in contrast to the theoretical reaction scheme. This effect is due to the disproportionation reaction of 2 molecules of carbon monoxide to 1 molecule each of carbon dioxide and carbon. This additional information can only be obtained by simultaneous measurement of the mass spectrum and is not evident from the curve alone.  This example summarizes the results obtained from the TGA MS analysis of an active pharmaceutical ingredient or API. In production, APIs are often recrystallized from different solvents in order to obtain the desired crystalline form. Afterwards, it is important to check that no unwanted solvent residues are left in the API. The TGA curve shows several weight loss steps in the temperature range up to 350 degrees Celsius. The initial weight loss below 60 degrees is probably due to the gradual evaporation of absorb moisture or solvents. While the final step above 250 degrees is no doubt due to the decomposition of the product. The 2 intermediate weight loss steps cannot be assigned from the TGA data alone. The MS intensity curves of the fragment ions 31 for methanol and 43 for acetone were measured simultaneously with the TGA curve and correspond to the weight loss steps in the temperature range, 70 to 190 and 190 to 225 degrees. The temperatures at which methanol and acetone are released during heating are much higher than the normal evaporation temperatures of these 2 solvents. This indicates that the solvents were bound inside the crystal structure of the API. The methanol is released at lower temperatures and over a wider temperature range, whereas the acetone is released at higher temperatures and in a rather narrow temperature range. This could mean that the acetone is more firmly bound in the substance, possibly as a solvent, whereas the methanol is trapped, but not bound in the crystal lattice. The purpose of the experiment shown here was to investigate the curing reaction of an amino resin and to analyze the main decomposition products. Ideally, the condensation reaction of an amino resin forms water during the cross-linking reaction. Depending on the conditions, undesired side reactions with the formation of other reaction products such as methanol and formaldehyde can also occur. The nature of the volatile products released in the reaction indicates whether or not the reaction is proceeding favorably. The TGA curve shows a gradual loss of weight in the range of 40 to 220 degrees Celsius due to the curing or poly compensation reaction of the amino resin. The maximum rate of weight loss is about 115 degrees, as shown by the DTG curve. The marked change in the TGA and DTG curves at about 220 degrees indicates that decomposition of the product begins at this temperature. MS fragment ion curves were recorded for several different master charge ratios. The evaporation of residual moisture and water with ion masses of 17 and 18 formed during the polycondensation reaction can be detected from about 50 degrees onward. The ion intensity curves of methanol with a Mastercharge ratio of 31 and formaldehyde with mass 30 are flat, up to about 220 degrees. This proves that these compounds are not formed below 220 degrees. Above 220 degrees, the intensities of the ions with masses of 17, 30, and 31 show a marked increase, indicating that the sample has begun to degrade. The intensity of the ion with mass 18, however, decreases noticeably. Since water is characterized by ions of mass 17 and 18, the intensity ratio of these 2 masses would normally be expected to be constant. This is obviously not the case, indicating that there must be another reason for the increase of the MOZ17 curve, for example, another ion with the same nominal mass. Measurements with FTIR were performed to clarify this point but are not shown here. A direct comparison of the FTIR spectrum measured at 240 degrees with database spectra indicated the presence of methanol, carbon dioxide and ammonia. The presence of ammonia with a mass to charge ratio of 17 explains why this curve increases. The next application illustrates the use of TGA FTIR. The aim of the experiment was to monitor the degradation and identify the nature of the decomposition products evolved during the pyrolysis of PVC up to 600 degrees Celsius. The TGA weight loss curve, derivative weight loss curve and an infrared chemigram show 2 distinct weight loss steps at about 310 degrees and 465 degrees. In this case, the infrared chemigram was a total intensity curve of the infrared absorption between 3,090 and 3,075 wave numbers and is shown by the dotted green line. The inset diagram on the left shows the FDIR spectrum recorded at 310 degrees. The sharp absorption bands between 3,100 and 2,600 wave numbers correspond to the spectrum of hydrogen chloride gas. This shows that the first weight loss step is caused by cleavage of hydrogen chloride gas from the main polymer chain of the PVC. The NCAT diagram on the right shows an FTIR spectrum measured at about 465 degrees. The spectrum in this spectral range is typical for benzene. The benzene is formed through cyclization of the carbon chain, which is made possible through the double bonds formed previously during the elimination of hydrogen chloride. Careful examination of the FDIR spectrum at 310 degrees indicates that a small amount of benzene was released in addition to hydrogen chloride. This is visible from the underlying benzene pattern in the spectrum. The presence of benzene could very likely be confirmed by performing additional MS measurements. This should be possible because mass spectrometry is much more sensitive than gas phase infrared spectroscopy. In this application, TGA FDIR was used to investigate the thermal degradation of bis hydroxy-ethylene-terephthalate or BHET. This substance is used in the production of PET bottles. The monomer is sometimes also formed during the recycling of PET bottles during the depolymerization process. The TGA and DTG curves in the upper part of the diagram show 2 distinct weight loss steps. FTIR Spectra were recorded simultaneously throughout the TGA measurement to identify the components released from the substance. Four different FDIR chemigrams or functional group profiles are plotted in the lower half of the diagram. The absorption frequencies are shown next to the chemigram and correspond to the characteristic CH stretching bands of alkanes, the CO absorption bands of alcohols and the carbon bands of carboxylic acids and esters. The chemigrams or functional group profiles show that the first weight loss step involves a decomposition product that contains alkane and alcohol functional groups. The FDIR spectrum measured at 300 degrees Celsius shows an excellent match with a reference library spectrum of ethylene glycol. Direct comparison of the spectrum recorded at 450 degrees with database Spectra did not, however, identify any one particular decomposition product. the functional group profiles show that the decomposition product contains an alcohol CO bond and carboxylic acid and ester functional groups. This information, together with some knowledge of the material leads one to assume that the second weight loss step is due to the elimination of hydroxyformic acid ester created through the cleavage of the side chains of the aromatic group.

Okay. So let's make another short stop here. So if you have questions, please use the chat. So another application example that you see here on the screen, I would like to explain to you now. Sometimes, TGA FTIR can be used to identify unknown plastics. And here was an example that I measured by myself. I got a plastic sample, and it was not clear what was the origin of the sample. First, the TGA analysis curve you see on the bottom, there are 2 rate loss steps one starts from about 250. And the second one starts at about 520. So from this, we could conclude there must be 2 components and one is in the high amount. The first rate loss step is about 89 percentage and the second is smaller than percentage. So what did we do? We connected the FTIR. And on the top, you see 2 Spectra and the first on the left side, was taken at 345 degrees. And here, with the spectral library search, we could easily identify formaldehyde, which is the typical decomposition product for [ pompolyoxinitaly ]. So we identified the first component, which is present in the high amount of 89 percentage. And now let's have a look at the spectrum at the right side that was taken at 570 degrees Celsius. And here, we see typical bands for tetra. So we could easily identify the origin of the second step, and this was PTFE. Altogether, we could identify this nonplastic in consists of 2 different components from and PTFE. There's also a user come available with this application. So if there are no questions at the moment, I suggest we continue, but you still have time to ask your questions, of course.

The following examples illustrate the use of TGA GCMS for determining the composition of an unknown rubber compound. The rubber was heated to 600 degrees Celsius under inert conditions. In this temperature range, volatile components vaporize as shown by the small step at about 250 degrees Celsius. This is followed by pyrolysis of the polymeric components shortly afterwards at about 370 degrees Celsius. The 2 peaks on the first derivative or DTG curve indicate that the sample is a blend of at least 2 components. The blue crosses on the TGA curve corresponded to the temperatures at which gas samples were stored for subsequent GCMS analysis. This slide displays the total ion chromatogram collected at a TGA temperature of 390 degrees Celsius. The main peaks were identified using the NIST MS library. More than 100 volatile decomposition compounds were evolved during the pyrolysis. The most interesting ones labeled in the TIC include limonene and its dimer 1.3-pentadiene for 4-ethanylcyclohexine, styrene, and alpha-Methylstyrene. An example of peak identification is shown on the right. The above diagram in blue is the mass spectrum recorded at a retention time of 12.167 minutes. Comparison of the Spectra with the NIST database showed that the peak in the chromatogram was clearly due to styrene with a quality factor of 97.  So-called emission profiles of selected compounds can be plotted together with the TGA curve as a function of temperature. Itinerary rubber blend based on natural rubber NR, butadiene rubber, BR and styrene butadiene rubber, SBR was identified after evaluating the peaks and all 16 total ion chromatograms. NR was detected during the first decomposition step based on the presence of limonene and isoprene. The detected compounds related to NR, BR and SBR are shown in the table. BR and SBR are mainly present during the second decomposition but are also detected in lower concentrations during the first step. This application describes how thermalgravimetric analysis coupled with Micro GC/MS can be used to investigate the processes that take place during the synthesis of barium titanate. Barium titanate belongs to a class of materials known as electro-ceramics and is, for example, used in ceramic capacitors. It is made by heating a stoichiometric mixture of barium carbonate and titanium dioxide. The compound is formed in a solid, solid reaction after calcination of the barium carbonate. The TGA measurement of the mixture is shown in black, the DTG curve in red and the simultaneously measured DSC curve in blue. Several mass losses can be identified. For example, between 50 and 300 degrees Celsius and between 300 and 600 degrees Celsius, there are mass losses that each amount to about 0.6%. They are presumably due to the loss of moisture and solvents used in the production of the starting materials. Calcination of barium carbonate begins from about 600 degrees Celsius onward and is completed by about 1,000 degrees Celsius. The several peaks in the DTG curve also observed in the DSC indicate that the calcination process occurs in several steps. The 2 curves appear quite similar up to about 780 degrees Celsius. The sharp endothermic peak at 828 degrees Celsius occurs during the solid, solid transition of gamma barium carbonate to beta barium carbonate. The solid, solid transition, beta barium carbonate to alpha barium carbonate is observed at 987 degrees Celsius. Both transitions take place during the calcination of barium carbonate and influence its kinetics. This explains the different peaks that occur in the DTG curve during calcination. At about 1,240 degrees Celsius, the DSC curve shows a further endothermic peak that is not accompanied by a mass loss. This corresponds to the solid, solid reaction of barium oxide with titanium dioxide to form barium titanate. About 15 milligrams of carbon dioxide is released during calcination. This means that the original sample contained about 68 milligrams, which corresponds to 7.25% barium carbonate. A stoichiometric reaction with titanium dioxide requires 28 milligrams of titanium dioxide. A residual mass of 81 milligrams is therefore expected. This agrees well with the measured residual mass. The starting mixture, therefore, corresponds to a stoichiometric mixture of barium carbonate and titanium dioxide, together with a total of about 1.2% volatile compounds.  In the next slide, we investigate whether the volatile compounds released before the onset of calcination can be identified using a suitable EGA technique. In this example, we decided to use the TGA Micro GC/MS equipped with 3 different modules for the detection of permanent light and medium gases. The MS detector was coupled to the module sensitive to medium compounds. The 2 chromatograms shown here were obtained from 2 different modules at different TGA temperatures. The TCD chromatogram on the left-hand side was obtained at a TGA temperature of 294 degrees Celsius. The curve indicated the presence of small amounts of water and carbon dioxide besides the matrix peak nitrogen. The total ion chromatogram at a TGA temperature of 486 degrees Celsius is shown on the right. The chromatogram shows 3 small peaks besides the matrix peak. The mass spectra measured during these weeks were identified as chloromethane, acetaldehyde and methanol using the NIST MS library. So-called emission profiles can then be constructed from the Micro GC/MS analyses. They present the relative concentration of selected decomposition products as a function of temperature. Examples of such emission profiles are displayed here together with the TGA curve. Only water is released up to 300 degrees Celsius. The curves between 300 and 600 degrees Celsius indicate that residues of solvents used in production of the starting materials are released besides water. From 600 degrees Celsius onward, the main mass loss of 15.7% is due to the calcination of barium carbonate in which only carbon dioxide is released.  Acrylonitrile butadiene styrene or ABS, for short, is generally supplied in granules for injection molding applications. The moisture content of these copolymers is important because it affects the processing of the material and final product quality. In this example, we show how the water content of an ABS granule can be determined by means of TGA Micro GC/MS. The diagrams show the TGA curve, the first derivative of the TGA curve, the DTG curve, the emission profiles for water, ethylbenzene, and styrene, and the DSC curve. The TGA curve shows a continuous decrease in sample mass from the start of the experiment, between room temperature and about 160 degrees Celsius, the DTG curve shows a shoulder at about 75 degrees Celsius and between 100 and 150 degrees Celsius are marked up and down effect, followed by a broad peak up to about 245 degrees Celsius. The up and down effect is due to the glass transition of the material. After the glass transition, the material flows together, which leads to a slower release of residual moisture. The glass transition of polystyrene in the ABS sample can be clearly seen on the DSC curve at about 101 degrees Celsius. The Micro GC/MS emission profiles show that the release of water, ethylbenzene and styrene overlap between approximately 140 and 180 degrees Celsius. It is, therefore, not possible to determine the water content of the ABS sample from the TGA curve alone. The exact water content can, however, be determined from the area below the emission profile for water. For this, a calibration measurement is required beforehand. EGA opens up many new application possibilities. The Mettler-Toledo concept allows any existing TGA instrument to be combined with a gas analysis system. Not all techniques are equally suitable for dealing with specific questions. The overview in the figure shows which technique is best for solving a particular application problem. TGA MS is an online technique and can detect very low concentrations of substances. It is ideal for the detection of residual solvents and small molecules such as water, carbon monoxide, carbon dioxide, sulfur oxides, nitrogen oxides or residual solvents, TGA FTIR is also an online technique and enables the detection of simple and complex compounds. It provides information about the structure of the detected gases. Interpretation of MS and FTIR data requires experience and previous information about the sample. Micro GC, Micro GC/MS and GCMS are ideal for the identification of unknown decomposition products. Permanent and lights can be detected by micro GC and medium compounds up to 8 hydrocarbons by Micro GC/MS, the coupling of a TGA with a storage interface and a conventional GCMS is recommended for the detection of volatile up to C18 hydrocarbon. Finally, I would like to draw your attention to further information about evolved gas analysis that you can download from the Internet. Mettler-Toledo publishes articles on thermal analysis and applications from different fields twice a year in UserCom, the well-known Mettler-Toledo Technical Customer Magazine. Back issues can be downloaded as PDF files from the Internet as shown at the bottom of this slide. Individual applications can be searched for on the Mettler-Toledo website. The evolved gas analysis, EGA handbook provides clear instructions to anyone interested in the practical aspects of TGA EGA and various application examples related to polymer materials such as plastics or rubbers as well as pharmaceutical, biomass, organic and inorganic materials. In addition, you can download information about application handbooks, webinars or of a more general nature from the Internet addresses given on this slide. This concludes my presentation on evolved gas analysis. Thank you very much for your interest and attention.

Also from my side, thanks for your attention. So far, we did not receive any questions. So you have another chance to use the chat for any questions. In the meantime, let me draw your attention to our upcoming webinars. So next month, we will talk about food. In June, we will give you some information about the compliance of the STAR software 21 CFR Part 11. And in July, we will give you an introduction about thermal optical analysis using the Hot Stage Microscopy. So there are no questions. So then I think we can thank you again for your attention. Thomas, we can close the session.

Thank you, everybody, for attending, and we hope to see you again in one of our next webinar that you see here. Thank you, and have a good rest of the day.

Is just one question. How can we get participation certificate?

Yes, send me your e-mail, then I will send you a participation certificate.

Okay. So if there's another question, we will just wait one more minute and then give you a chance to ask. So we have a question now. Why do we call GTMS CMIC quantitative because quantification on the MS curves may be rather difficult. First, we -- if you have complex mixtures, we have no separation. The peaks we detect may come from different components -- and to do some quantification, we would need some reference substance. So for example, for TGA GCMs, we could use predefined gases that contain the substance we want to quantify. This is not possible for TGA MS. If you know that you have only hydrogen evolving, still you would need some reference. You would need some reference because here with GCMs, we always inject the same amount from the loops from the storage loops. But here, -- not all the gas is coming from the MS will go into the -- from the TGA will go into the MS. We have a situation that the position of the capillary, the secondary multiplied voltage and also the flow rate can have an influence. So it will be rather difficult for MS to do the quantification. Regarding the slides, we do not provide to send you the slides, but you can find on our website webinars on demand there. You may have a look at the presentation again. For questions about troubleshooting who can help. The first contact would be in your country, your local sales representatives or application specialists for us. So that's the situation how it goes.  Another question, can I make calibration with the gas mixture of inert hydrogen? You can try but it can be demanding, but you can try if you have some source, then we also did once a calibration by MS, but it's rather demanding. But if you just expect hydrogen, maybe you have a biomass that is doing some decomposition, then you can try with hydrogen. Methane could be the same, but then you need calibration gas with amount of methane. So you can buy this. I know my colleague bottles with known amount of special gases and then he could do a quantification on the Micro GC/MS. So if there are no more questions now, then we thank you again for your attention, and we say bye-bye for today.