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Making a better beer with chemistry

Making a better beer with chemistry

Lager or ale? Pale ale or stout? Specialty beer, or basic draft? This week, to celebrate the International Beer Day on Friday, August 7th, I have chosen to write about a subject near and dear to me: how to make a better beer! Like many others, at the beginning of my adult life, I enjoyed the beverage without giving much thought to the vast array of styles and how they differed, beyond the obvious visual and gustatory senses. However, as a chemist with many chemist friends, I was introduced at several points to the world of homebrewing. Eventually, I succumbed.

Back in 2014, my husband and I bought all of the accessories to brew 25 liters (~6.5 gallons) of our own beer at a time. The entire process is controlled by us, from designing a recipe and milling the grains to sanitizing and bottling the finished product. We enjoy being able to develop the exact bitterness, sweetness, mouthfeel, and alcohol content for each batch we brew.

Over the years we have become more serious about this hobby by optimizing the procedure and making various improvements to the setup – including building our own temperature-controlled fermentation fridge managed by software. However, without an automated system, we occasionally run into issues with reproducibility between batches when using the same recipe. This is an issue that every brewer can relate to, no matter the size of their operation.

Working for Metrohm since 2013 has allowed me to have access to different analytical instrumentation in order to check certain quality attributes (e.g., strike water composition, mash pH, bitterness). However, Metrohm can provide much more to those working in the brewing industry. Keep reading to discover how we have improved analysis at the largest brewery in Switzerland.

Are you looking for applications in alcoholic beverages? Check out this selection of FREE Application Notes from Metrohm:

Lagers vs. Ales

There are two primary classes of beer: lagers and ales. The major contrast between the two is the type of yeast used for the fermentation process. Lagers must be fermented at colder temperatures, which lends crisp flavors and low ester formation. However, colder processes take longer, and so fermentation steps can last for some months. Ales have a much more sweet and fruity palate of flavors and are much easier to create than lagers, as the fermentation takes place at warmer temperatures and happens at a much faster rate.

Comparison between the fermentation of lagers and ales.

Diving a bit deeper, there are several styles of beer, from light pilsners and pale ales to porters and black imperial stouts. The variety of colors and flavors depend mostly on the grains used during the mash, which is the initial process of soaking the milled grains at a specific temperature (or range) to modify the starches and sugars for the yeast to be able to digest. The strain of yeast also contributes to the final flavor, whether it is dry, fruity, or even sour. Taking good care of the yeast is one of the most important parts of creating a great tasting beer.

Brewing terminology

  • Malting: process of germinating and kilning barley to produce usable sugars in the grain
  • Milling: act of grinding the grains to increase surface area and optimize extraction of sugars
  • Mashing: releasing malt sugars by soaking the milled grains in (hot) water, providing wort
  • Wort: the solution of extracted grain sugars
  • Lautering: process of clarifying wort after mashing
  • Sparging: rinsing the used grains to extract the last amount of malt sugars
  • Boiling: clarified wort is boiled, accomplishing sterilization (hops are added in this step)
  • Cooling: wort must be cooled well below body temperature (37 °C) as quickly as possible to avoid infection
  • Pitching: prepared yeast (dry or slurry) is added to the cooled brewed wort, oxygen is introduced
  • Fermenting: the process whereby yeast consumes simple sugars and excretes ethanol and CO2 as major products

Ingredients for a proper beer

These days, beer can contain several different ingredients and still adhere to a style. Barley, oats, wheat, rye, fruit, honey, spices, hops, yeast, water, and more are all components of our contemporary beer culture. However, in Bavaria during the 1500’s, the rules were much more strict. A purity law known as the Reinheitsgebot (1516) stated that beer must only be produced with water, barley, and hops. Any other adjuncts were not allowed, which meant that other grains such as rye and wheat were forbidden to be used in the brewing process. We all know how seriously the Germans take their beer – you only need to visit the Oktoberfest once to understand!

Determination of the bitterness compounds in hops, known as «alpha acids», can be easily determined with Metrohm instrumentation. Check out our brochure for more information:

You may have noticed that yeast was not one of the few ingredients mentioned in the purity law, however it was still essential for the brewing process. The yeast was just harvested at the end of each batch and added into the next, and its propagation from the fermentation process always ensured there was enough at the end each time. Ensuring the health of the yeast is integral to fermentation and the quality of the final product. With proper nutrients, oxygen levels, stable temperatures, and a supply of simple digestible sugars, alcohol contents up to 25% (and even beyond) can be achieved with some yeast strains without distillation (through heating or freezing, as for eisbocks).

Improved quality with analytical testing

Good beers do not make themselves. For larger brewing operations, which rely on consistency in quality and flavor between large batch volumes as well as across different countries, comprehensive analytical testing is the key to success.

Metrohm is well-equipped for this task, offering many solutions for breweries large and small.

Don’t take it from me – listen to one of our customers, Jules Wyss, manager of the Quality Assurance laboratory at Feldschlösschen brewery, the largest brewery in Switzerland.

«I have decided to go with Metrohm, because they are the only ones who are up to such a job at all. They share with us their huge know-how.

I can’t think of any other supplier who would have been able to help me in the same way

Jules Wyss

Manager Quality Assurance Laboratory, Feldschlösschen Getränke AG

Previous solutions failed

For a long time, Jules determined the quality parameters in his beer samples using separate analysis systems: a titrator, HPLC system, alcohol measuring device, and a density meter. These separate measurements involved a huge amount of work: not only the analyses themselves, but also the documentation and archiving of the results all had to be handled separately. Furthermore, Jules often had to contend with unreliable results – depending on the measurement procedure, he had to analyze one sample up to three times in order to obtain an accurate result.

A tailor-made system for Feldschlösschen

Jules’ close collaboration with Metrohm has produced a system that takes care of the majority of the necessary measurements. According to Jules, the system can determine around 90% of the parameters he needs to measure. Jules’ new analysis system combines various analysis techniques: ion chromatography and titration from Metrohm as well as alcohol, density, and color measurement from another manufacturer. They are all controlled by the tiamo titration software. This means that bitterness, citric acid, pH value, alcohol content, density, and color can all be determined by executing a single method in tiamo.

Measurement of the overall water quality as well as downstream analysis of the sanitization process on the bottling line is also possible with Metrohm’s line of Process Analysis instrumentation.

Integrated analytical systems with automated capabilities allow for a «plug and play» determination of a variety of quality parameters for QA/QC analysts in the brewing industry. Sample analysis is streamlined and simplified, and throughput is increased via the automation of time-consuming preparative and data collection steps, which also reduces the chance of human error.

Something to celebrate: The Metrohm 6-pack (2018)

In 2018, Metrohm celebrated its 75 year Jubilee. At this time, I decided to combine my experience as a laboratory analyst as well as a marketing manager to brew a series of six different styles of beer for the company, as a giveaway for customers of our Metrohm Process Analytics brand, for whom I worked at the time. Each batch was brewed to contain precisely 7.5% ABV (alcohol by volume), to resonate with the 75 year anniversary. The array of ales was designed to appeal to a broad audience, featuring a stout, porter, brown ale, red ale, hefeweizen, and an India pale ale (IPA). Each style requires different actions especially during the mashing process, based on the type of grains used and the desired outcome (e.g., flavor balance, mouthfeel, alcohol content).

Bespoke bottle caps featuring the Metrohm logo.
The 6 styles of beers brewed as a special customer giveaway to celebrate the Metrohm 75 year Jubilee.

Using a Metrohm Ion Chromatograph, I analyzed my home tap water for concentrations of major cations and anions to ensure no extra salts were needed to adjust it prior to mashing. After some of the beers were prepared, I tested my colleagues at Metrohm International Headquarters in the IC department, to see if they could determine the difference between two bottles with different ingredients:

Overlaid chromatograms from IC organic acid analysis highlighting the differences between 2 styles of the Metrohm 75 year Jubilee beers.

The IC analysis of organic acids and anions showed a clear difference between the beers, allowing them to determine which sample corresponded to which style, since I did not label them prior to shipping the bottles for analysis. As the milk stout contained added lactose, this peak was very pronounced and a perfect indicator to use.

Metrohm ion chromatography, along with titration, NIRS, and other techniques, allows for reliable, comprehensive beer analysis for all.

In conclusion, I wish you a very happy International Beer Day this Friday. Hopefully this article has illuminated the various ways that beer and other alcoholic beverages can be analytically tested for quality control parameters and more  fast, easy, and reliably with Metrohm instrumentation.

For more information about the beer quality parameters measured at Feldschlösschen brewery, take a look at our article: «In the kingdom of beer The largest brewery in Switzerland gets a made-to-measure system». Cheers!

Read the full article:

«In the kingdom of beer – The largest brewery in Switzerland gets a made-to-measure system»

Post written by Dr. Alyson Lanciki, Scientific Editor (and «chief brewing officer») at Metrohm International Headquarters, Herisau, Switzerland.

History of Metrohm IC – Part 1

History of Metrohm IC – Part 1

Ion chromatography (IC) has been a part of the Metrohm portfolio of analytical chemical instrumentation since 1987, and in that span of 33 years, several new and exciting developments have been introduced challenging the limits of what IC can do. From simple setups for academic laboratories, to hyphenated techniques (e.g., IC-ICP-MS) broadening the capabilities of chemical analysis – we’ve done it! This week, I would like to begin to unveil the history of this analytical method at Metrohm and how it has changed over the intervening decades.

«The mid-1980‘s. Our mission: develop an affordable ion chromatograph with a minimal footprint, simple to use, providing outstanding measurements.»

Walter Terzer, R&D ion chromatography, Metrohm AG

«The 690 Ion Chromatograph was engineered for people without a PhD in chemistry, too. And it was so rugged that quite a few 690 IC’s are used even today. Most importantly: At the time, it cost only half as much as our competitor’s product!»

Dr. Markus Läubli, R&D ion chromatography, Metrohm AG

The beginning: 1980’s

Ion chromatography was added to the Metrohm portfolio in 1987, broadening our span of techniques, which at the time only included titration, meters, voltammetry, and the Rancimat. IC, already a couple of years on the market, was seen on one hand as a very interesting method, but on the other hand also as a very complex and expensive technology.

The increasing viability of IC for previously typical titration applications guided Metrohm to focus on this method.

The Metrohm 636 Titroprocessor.

Development of the conductivity detector

Conductivity is the most common detection technique used with ion chromatography. Conductivity is the inherent sum parameter of all ions in aqueous solution. As ion chromatography is performed using aqueous solutions such as eluents (i.e. the mobile phase) and samples, conductivity is the essential detection mode.

You can see how this is measured in the video below. Other detection techniques can be used as well, but typically are applicable only in special cases.

The modernized, compact, and intelligent Metrohm IC Conductivity Detector.

In the early 1980s, the method of IC began to compete for market share with titration. Based on positive experiences with the amperometric detector (641 VA Detector, introduced in 1980, and originally sold as an HPLC detector) and Metrohm’s competence in conductivity measurement, this led to the idea to develop a conductivity detector in a similar manner. A prerequisite for the project was the availability of separation columns (stationary phase) which allowed analysts to reach detection limits of 1 mg/L (or lower) of the standard anions.

The Metrohm 641 VA Detector.

In 1984, a test was run on an initial setup consisting of a single-piston HPLC pump, a 6-port injector, commercially available IC separation columns, a conductivity detector, and a chart recorder (586 Labograph). This test proved that the 1 mg/L limit could be reached, and thus the project of developing an official Metrohm conductivity detector began.

At that time, chemical suppression introduced by Small, Stevens, and Baumann [1] was patented and not available. However, non-suppressed conductivity detection described by Gjerde, Schmuckler, and Fritz [2] was seen as a viable alternative. When measurement of low concentrations of ions in solution was necessary, the very small chromatographic peaks plus the high conductivity background from the mobile phase (eluent) created a challenge, and special requirements for the conductivity detector had to be taken into account. The most critical of these was the temperature coefficient of the conductivity, which is typically around 2%/°C. This requires maintaining an extremely stable temperature during the measurement.

During the initial development phase it was found that, aside from bulk measurement, platinum was not the best material for electrodes in a flow-through cell. However, stainless steel worked perfectly. The measuring cell still needed to be insulated, however, insulation alone was not sufficient. Active thermostating was required to achieve a temperature stability of better than 0.01 °C. That stability was measured with a thermocouple, and recorded on the Labograph. Later on, with more sophisticated tools the stability was determined to be better than 0.001 °C.

Even after all of this hard work, the initial system baseline stability was still not good enough. As it turned out, several components of the IC system needed to be thermally stabilized. Additionally, the different brand of HPLC pump was not optimal for the development of the Metrohm ion chromatograph.

The Metrohm 690 Ion Chromatograph.

The first decision was to put the conductivity detector project to the side, and start building an ion chromatograph. Thus, the first Metrohm IC (the 690 Ion Chromatograph) was developed. The 690 IC consisted of: a foam polymer housing for perfect thermal insulation, the electronic and detector block, as well as a pulse dampener, a sample injector, and separation column. All capillary connections consisted of HPLC capillaries at the time (made from stainless steel). The inadequate HPLC pump was replaced and upgraded with a Metrohm IC Pump, and the Labograph was almost immediately followed by an integrator, which completed the IC system.

Despite the general consensus in the 1980s that ion chromatography was only robust while using metal-free instruments, Metrohm was able to run anion, cation, and ion-exclusion chromatography on stainless steel-based systems. Even determinations of heavy metals were performed without issues.

Conductivity detection with «electronic suppression»

A drawback of non-suppressed IC is the relatively high inherent baseline noise, due to high conductivity levels from the mobile phase. Parameters which add to this baseline noise include temperature induced fluctuations, pump noise, and electronic noise.

The temperature influence on baseline noise was minimized thanks to the near perfect thermal stabilization of the detector. The quality of the high pressure pump is important to stabilize the baseline, however, under standard running conditions it does not add much to the baseline noise. Finally, after optimizing these points, it was clear that the electronic noise was the most important parameter on which to focus. Each electronic component influences temperature fluctuations and also adds some amount of noise.

Internal view of the Metrohm 690 IC. The conductivity detector is highlighted.

The thermostated detector block consisted of an aluminum block for thermostating, a built-in measuring cell, and an electronic preamplifier. This preamplifier guaranteed that the measured analog conductivity signal was insensitive to external fields when guided to the main electronics.

Auto Zero function for background compensation purposes during measurement.

The Auto Zero function measured the actual conductivity at initialization of the function and was subtracted from the signal throughout the chromatogram. This can be called background compensation. The «electronic suppression» designation is given due to an electronic setup which additionally reduced the electronic noise. The idea behind this is as simple as it was effective. The electronics were set to measure the actual conductivity signal as well as the measured background conductivity through two parallel paths with identical electronic components. Subtraction of the two signals was done just prior to the output to the external A/D converter. Under an assumption that the same components should add the same noise and exhibit similar thermal behavior, both signals are influenced in the same manner. Therefore, the noise level was minimized even further.

Additionally, the apparent noise level was improved using the optimal output window (called «Full-scale») in units of [µS/cm]. The Metrohm Application Note AN-C-032 describes this effect. At that time, this noise level of approximately 2 nS/cm was similar to or better than analyses performed with chemical suppression.

Separation column developments

At market launch in late 1987, Metrohm offered a total of six IC separation columns: two suitable for anions, one for monovalent cations, one for divalent cations, and one for organic acids (ion-exclusion). At that time, the group of Prof. Dr. Schomburg (Institut für Kohlenforschung, Mühlheim/Ruhr, DE) studied the preparation of HPLC phases by coating polymer materials on to e.g. silica. One of the phases used was poly(butadiene/maleic acid) on a silica material, which was found to be able to separate mono- and divalent cations in a single isocratic run. Metrohm acquired the technology and started column production in Herisau, Switzerland.

The so-called «Schomburg column» or later «Super-Sep Cation column» was the very first column on the market allowing the simultaneous separation of alkali and alkaline earth metal cations. Even the current Metrosep C 4 and Metrosep C 6 columns’ roots date back to the Schomburg column.

Data handling capabilities

In the first months on the market, only the Labograph (a chart recorder) was available for the new IC. This was of course not really acceptable. Nevertheless, results achieved by cutting out and physically weighing the peaks were quite correct. The first integrator (Shimadzu C-R5A) was a tabletop integrator with LCD display (2 lines), storage capabilities (2 chromatograms in the instrument, and 5 chromatograms per external card), and a thermo-printer for documentation.

Top: Metrohm 690 Ion Chromatograph with Labograph on the left, and separation columns in the foreground.
Bottom: Metrohm 690 Ion Chromatograph with the Shimadzu C-R5A tabletop integrator on the left.

In 1991, the first PC-based data acquisition and handling software (714 IC-Metrodata) was developed, consisting of a data acquisition box and the DOS-based integration software. Five years later in 1996, the software of the 714 IC-Metrodata was updated to a Windows version. Then in 2000, the new IC Net software was released together with the 762 IC Interface and 771 IC Compact interface for both data acquisition and remote control capabilities.

The 690 IC featuring the 714 IC-Metrodata, ushering scientists into a new era of peak integration possibilities.

What’s next?

Stay tuned for the next installment in this series, covering the 1990s and early 2000s. During this time, Metrohm developed modular IC, the Metrohm Suppressor Module (MSM), as well as some outstanding separation columns. Subscribe to the blog below so you don’t miss out!

Download our free Monograph for more information

Practical Ion Chromatography – An Introduction

References

[1] Small, H.; Stevens, T.S.; W.C. Baumann. Novel ion exchange chromatographic method using conductimetric detection. Anal. Chem. 1975, 47 (11), 1801–1809. https://doi.org/10.1021/ac60361a017

[2]  Gjerde, D. T.; Fritz, J. S.; Schmuckler, G. Anion Chromatography with Low-Conductivity Eluents. J. Chromatogr. A 1979, 186, 509–519. https://doi.org/10.1016/S0021-9673(00)95271-3

Post written by Dr. Markus Läubli, Manager Marketing Support IC at Metrohm International Headquarters, Herisau, Switzerland.

Frequently asked questions in Karl Fischer titration – Part 1

Frequently asked questions in Karl Fischer titration – Part 1

Since I started working at Metrohm more than 15 years ago, I have received many questions about Karl Fischer titration. Some of those questions have been asked repeatedly from several people in different locations around the world. Therefore, I have chosen 20 of the most frequent questions received over the years concerning Karl Fischer equipment and arranged them into three categories: instrument preparation and handling, titration troubleshooting, and the oven technique. Part 1 will cover instrument preparation and handling, and Part 2 will cover the other two topics.

Summary of questions in the FAQ (click to go directly to each question):

Instrument preparation and handling

1.  How can I check if the electrode is working correctly?

I recommend carrying out a volumetric or coulometric Karl Fischer titration using a certified water standard as sample. In volumetry, you can carry out a threefold titer determination followed by a determination of a different standard. Then, you can calculate the recovery of the water content determination of the standard.

To check a coulometric system, carry out a threefold determination with a certified water standard and calculate the recovery. If the recovery is between 97–103%, this indicated that the system, including the electrode, is working fine.

The color of the working medium is an additional indicator as to whether the indication is working properly.

Pale yellow is perfect, whereas dark yellow or even pale brown suggests indication problems. If this happens, then the indicator electrode should be cleaned.

Check out questions 7 and 8 for tips on the cleaning of the indicator electrode.

2.  How long can an electrode be stored in KF reagent?

Karl Fischer electrodes are made from glass and platinum. Therefore, the KF reagent does not affect the electrode. It can be stored in reagent as long as you want.

3.  Can the molecular sieve be dried and reused, or should it be replaced?

The molecular sieve can of course be dried and reused. I recommend drying it for at least 24 hours at a temperature between 200–300 °C. Afterwards, let it cool down in a desiccator and then transfer it into a glass bottle with an airtight seal for storage. 

4.  How long does conditioning normally take?

Conditioning of a freshly filled titration vessel normally takes around 2–4 minutes for volumetry, depending on the reaction speed (type of reagent), and around 15–30 minutes for coulometry. In combination with an oven, it might take a bit longer to reach a stable drift owing to the constant gas flow. I recommend stabilizing the entire oven system for at least 1 hour before the first titration.

Between single measurements in the same working medium, conditioning takes approximately 1–2 minutes. Take care that the original drift level is reached again.

5.  When conditioning, many bubbles form in the coulometric titration cell with a very high drift, also when using fresh reagent. What could be the reason for this effect?

At the anode, the generator electrode produces iodine from the iodide-containing reagent. The bubbles you see at the cathode are the result of the reduction of H+ ions to hydrogen gas.

After opening the titration cell or after filling it with fresh reagent, the conditioning step removes any moisture brought into the system, avoiding a bias in the water content determination of the sample. Removing the water results in an increased drift level. During conditioning, the aforementioned H2 is generated. The gas bubbles are therefore completely normal and not a cause for concern. Generally, the following rule applies: The more moisture present in the titration vessel, the higher the drift value will be, and the more hydrogen will form.

6.  What is the best frequency to clean the Karl Fischer equipment?

There is no strict rule as to when you should clean the KF equipment. The cleaning intervals strongly depend on the type and the amount of sample added to the titration cell. Poor solubility and contamination of the indicator electrode (deposition layer on its surface) or memory effects due to large amounts of sample can be good reasons for cleaning the equipment.

The drift can be a good indicator as well. In case you observe higher and unstable drift values, I would recommend cleaning the titration cell or at least refilling the working medium.

7.  How do I clean the Karl Fischer equipment?

For a mounted titration vessel, it can be as simple as rinsing with alcohol. For an intense cleaning, the vessel should be removed from the titrator. Water, solvents like methanol, or cleaning agents are fine to clean the KF equipment. Even concentrated nitric acid can be used as an oxidizing agent, e.g. in case of contaminated indicator electrodes or coulometric generator electrodes.

All of these options are fine, but keep in mind that the last cleaning step should always be rinsing with alcohol followed by proper drying in a drying oven or with a hair dryer at max. 50 °C to remove as much adherent water as possible.

You should never use ketones (e.g., acetone) to clean Karl Fischer equipment, as they react with methanol. This reaction releases water. If there are still traces of ketones left in the titration cell after cleaning, they will react with the methanol in the KF reagent and might cause the drift to be too high to start any titration.

8.  Is it also possible to use a cleaning agent like «CIF» or toothpaste to clean the double Pt electrode?

Normally, rinsing with alcoholic solvents and polishing with paper tissue should be enough to clean the indicator electrode. You may also use detergents, toothpaste, or the polishing set offered by Metrohm! Just make sure that you rinse the electrode properly after the cleaning process to remove all traces of your chosen cleaning agent before using the electrode again.

Cleaning instructions can also be found in our video about metal and KF electrode maintenance:

9.  How do I clean a generator electrode with a diaphragm?

After removing the generator electrode from the titration vessel, dispose the catholyte solution, then rinse the electrode with water. Place the generator electrode upright (e.g., in an Erlenmeyer flask) and cover the connector with the protection cap to prevent corrosion. Fill the generator electrode with some milliliters of concentrated nitric acid, and let the acid flow through the diaphragm. Then fill the cathode compartment with water, and again allow the liquid to flow through the diaphragm. Repeat the rinsing step with water several times to make sure that all traces of nitric acid are washed out of the diaphragm.

Please note that the nitric acid treatment can be left out if the level of contamination does not require it.

Finally, pour some methanol into the generator electrode to remove the water. Repeat this step a few times to remove all traces of water. The last step is properly drying the electrode in a drying oven or with a hair dryer at max. 50 °C. After this cleaning procedure, the electrode is as good as new and can be used again for titrations.

Keep on the lookout for our next installment in this two-part series, or subscribe to the blog below so you’re sure not to miss it! In Part 2, I will cover the topics of KF titration troubleshooting and the Karl Fischer oven technique.

Post written by Michael Margreth, Sr. Product Specialist Titration (Karl Fischer Titration) at Metrohm International Headquarters, Herisau, Switzerland.

A History of Chemistry – Part 4

A History of Chemistry – Part 4

This article is the final installment in our four-part series on the history of chemistry. Did you miss the others? Don’t worry – you can find them all here:

The industrialization of electrochemistry

Michael Faraday (1791–1867) had a modest upbringing. He was 14 years old when he began his bookbinding apprenticeship. The young Faraday read a multitude of works that he received for binding and thus educated himself in the sciences as well as in literature and art. A customer at the bookbinding workshop noticed the curious apprentice and mentioned him to his father, who then took Faraday with him to several lectures given by electrochemistry pioneer Humphry Davy. Shortly after, Faraday began working for Davy.

As his assistant, Faraday traveled with Davy across Europe, as they carried out experiments together and met numerous influential scientists. Back in England, Faraday continued training as a chemist and in 1833 became a professor of chemistry. During this time, he investigated the basic laws of electrolysis. These formed the basis of electrochemistry and, in the second half of the century, enabled the development of an electrochemical industry which manufactured products such as chlorine, hydrogen, aluminum, magnesium, sodium, and potassium in its plants located at hydroelectric power stations.

Solvay’s soda ash

The industrial production of soda ash (sodium carbonate) had been possible since the development of the Leblanc process at the end of the 18th century. However, the synthesis required expensive raw materials and produced large amounts of the byproduct hydrogen chloride, which is toxic to the environment in which it is introduced. The produced hydrogen chloride escapes from industrial stacks and kills surrounding vegetation, and is also lethal to aquatic life when added to water.

During the second half of the 19th century, the Belgian Ernest Solvay (1838–1922) occupied himself with the issue. Solvay, who came from an industrialist family, had little formal education but was familiar with chemical procedures thanks to his work at his uncle’s and father’s factories. He developed the process for manufacturing soda ash, which was named after him and only has one byproduct – the harmless calcium chloride (CaCl2).

In 1861, Ernest Solvay and his brother Alfred began soda ash production in their own small factory in Brussels. By continuously adjusting the process, they became increasingly successful and continued to expand. Solvay, who had become very wealthy, became active in furthering scientific research and charitable causes. He also showed his sense of social responsibility in his factories: he established an eight-hour workday, paid holiday leave, a social security system, and a pension for his employees –long before it was legally mandatory.

The majority of the soda ash produced today is still created using the Solvay process.

Would you like to learn more?

Visit our site to read more about the Solvay process and the associated analysis techniques:

The periodic table of elements

There had already been 64 chemical elements had discovered by 1868. However, there was as yet no clear system of regulating which particular atom combinations formed new molecules. Sorting the elements based on their atomic mass had not offered a solution up to this point.

Dmitri Mendeleev (1834–1907) recognized a pattern here: when elements are sorted by their atomic mass, certain elemental properties are periodically repeated – specifically, after every eight elements. Mendeleev therefore retained the arrangement in ascending order of atomic mass, but then also sorted the elements that had the same properties below one another. Whenever properties were repeated after fewer than eight elements, he left open gaps to be filled with elements that had not yet been discovered. Mendeleev arranged the transition elements, which did not fit with his «octet rule», into their own column. This resulted in the first periodic table of elements in 1869.

From aniline to aspirin

Organic chemistry, which now went far beyond the synthesis of artificial urea, had become a significant and rapidly growing industry. The tar dye companies BASF, Bayer, and Hoechst, all of which were founded in the 1860s, grew so rapidly that they were employing thousands of people even before the turn of the century. From the end of the 19th century, the tar dye industry also developed synthetic organic medicinal products. Bayer, for example, patented the byproduct-free synthesis of acetylsalicylic acid in 1898 and marketed the product under the name «Aspirin» from the beginning of the 20th century.

In basic research, chemists began devoting themselves to increasingly complex organic molecules. Emil Fischer (1852–1919) investigated biologically significant molecules such as sugars and amino acids. In 1890, he used glycerin as a basis for synthesizing three sugars: glucose, fructose, and mannose. He later researched proteins. During this period, he discovered new amino acids and shed light on the type of bond which connects them to one another: an amide bond which he gave the name «peptide bond» [1].

First World War: Artificial fertilizer and warfare agents

The use of fertilizer had been common practice throughout agriculture ever since Liebig proved that it would improve yield. The nitrogen needed by plants for growth was added to fertilizers largely in the form of guano. This consists of the weathered excrement of seabirds which forms meter-thick layers over many years, particularly on the beaches of South America, where there are low levels of precipitation. In order to meet the high demand for food – and thus for fertilizer – entire shiploads of guano were being imported to Europe.

However, the import of guano could not keep pace with the rapid growth of population indefinitely, so at the end of the 19th century, researchers began looking for a way to fix nitrogen from the air. The German chemist Fritz Haber (1868–1934) eventually found a solution in 1909 and, with his ammonia synthesis, prevented the famine prophesied in the western world. Unfortunately, this development also enabled Germany’s production of warfare agents during the First World War, as ammonia could be used to create ammonium nitrate, which was then used in ammunition.

Fritz Haber
Carl Bosch

In the Haber-Bosch process, ammonia is produced as a result of a reaction between hydrogen and nitrogen. Fritz Haber achieved synthesis at a high temperature and a high pressure level, and with the aid of a catalyst. Carl Bosch (1874–1940) developed the industrial implementation of the process. For this purpose, he developed specific equipment made of state-of-the-art materials which could withstand both high pressure and temperature levels.

In 1914, the First World War broke out. The nations involved, as well as neutral states, faced blockades in their trade routes and had to become largely self-sufficient. Thanks to governmental structuring and aid, this led to a boom in industrial research across the globe. Numerous reputable scientists were actively involved in the war or supported it, including Fritz Haber, Walther Nernst, and Emil Fischer. In addition to the Haber-Bosch process, the pressure to create innovations that prevailed before and during the war also resulted in the first synthetic rubber as well as mustard gas and the toxic gas phosgene. Chlorine gas, which is produced during ammonia synthesis, was also used as a warfare agent during World War One.

What if . . .

. . . the Haber-Bosch process didn’t exist? Without the nitrogen fertilizer produced using the Haber-Bosch process, there would likely be a lot fewer people on Earth: the population growth of around 1.6 billion in 1900 to nearly 8 billion today would not have been possible without yield improvements brought about by artificial nitrogen fertilizers. Agriculture is still dependent on it today: without this process, the planet would only be able to provide enough food for half the population [2].

Chemistry since WWI

Following the armistice agreement in 1918, the German chemical industry – which had been world-leading until then – lost all of its patents and had to reveal numerous production secrets in order to satisfy the reparation demands of the victorious Allied Powers [3]. The German chemical industry, which had been the world’s largest at the time, had to relinquish its place at the top. Although it experienced another upswing toward the beginning of the Second World War, today’s leading lights in the chemical industry are the USA and France. During the post-war period, polymer chemistry and pharmaceutical chemistry were the fields that saw particular advancement and brought about countless products which are still essentials today. Among these are polymers, including synthetic fibers such as nylon and polyester, and artificially produced vitamins and hormones.

The time around the turn of the 20th century saw rapid advancement in chemistry, both in fundamental research as well as in industry – and to a great extent, it is the relationship between the two which enabled this progress. Numerous processes developed during this time period, including the Haber-Bosch and Solvay processes, have remained the methods of choice in the production of chemicals – in this case ammonia and soda ash, respectively – to this very day. 

References

[1] The Components of Life: From Nucleic Acids to Carbohydrates; 1st ed., Rogers, K., Ed.; Britannica Educational Publishing/Rosen Educational Services: New York, 2011; p 59.

[2] Erisman, J. W., Sutton, M. A., Galloway, J., Klimont, Z., and Winiwarter, W. (2008) Nat. Geosci. 1, 636–639.

[3] Kricheldorf, H. R. Menschen und ihre Materialien: Von der Steinzeit bis heute; 1st ed., Wiley-VCH Verlag & Co. KGaA: Weinheim, 2012; p 111.

Post written by Dr. Alyson Lanciki, Scientific Editor at Metrohm International Headquarters, Herisau, Switzerland. Primary research and content contribution done by Stephanie Kappes.

A History of Chemistry – Part 3

A History of Chemistry – Part 3

This article is the third in our four-part series on the history of chemistry. Missed the first two? Don’t worry – you can read both of them here:

Chemistry and society: An explosive pair

It is the early 19th century, and industrialization in Europe is in full swing. Close collaboration between the chemical industry and research – largely in France to start with, then followed by other European countries – is resulting in rapid advances in both sectors. As the chemical industry grows, chemistry is gaining a higher profile in society. The third and fourth parts of our series on the history of chemistry consider the relationship between chemistry, industry, and society from the 19th century onward.

The chemistry of living organisms

One of the most important chemists of the early 19th century is Jöns Jakob Berzelius (1779–1848). This Swedish scientist improved laboratory techniques and developed methods for elemental analysis. By conducting systematic analyses on a large scale, he determined the molecular formulae of virtually all known inorganic compounds and the atomic masses of the elements that had been discovered at that point. He is also the person we have to thank for element symbols: H for hydrogen, O for oxygen, and so on. The only difference between his notation and what we use today is that Berzelius presented element proportions in molecular formulae as superscript characters rather than the subscript characters we see nowadays (e.g., H2O instead of H2O). 

As well as this, he dealt extensively with the chemistry of organisms, something which he dubbed «organic chemistry». Being a proponent of vitalism, Berzelius was convinced that only living organisms were capable of producing organic substances, claiming that «vital force» was necessary for this process. The findings of one of his apprentices, Friedrich Wöhler, would later put a question mark on this hypothesis.

Organic from inorganic – is it possible?

In 1828, Friedrich Wöhler (1800–1882) was the first person who successfully managed to synthesize an organic compound from inorganic reagents: by heating ammonium cyanate, he was able to create its organic isomer, urea. He thus showed that organic substances can be created in a laboratory and that humans are therefore able to imitate and manipulate nature. More and more organic syntheses were made possible as the 19th century progressed.

Wöhler’s synthesis of urea was revolutionary. Today, urea is produced industrially at a rate of 150 million tons per year. Among other things, it is used for dermatological products and in the polymer industry.

Metrohm offers you solutions for the determination of urea and its contaminants. To find out more, visit our industry page «Chemical» and choose «Basic chemicals»:

Wöhler and Liebig: A fruitful friendship

Wöhler formed a friendship with Justus von Liebig (1803–1873) after they settled a dispute about silver fulminate and silver cyanate in 1825. Both substances share the same molecular formula, but the silver fulminate discovered by Liebig is highly explosive, whereas Wöhler’s silver cyanate is not. They eventually ascertained that the type and number of atoms in a compound alone are not enough to characterize a substance – the arrangement of the atoms must also be considered. As well as a spirit of mutual esteem, Liebig and Wöhler thus discovered isomerism. However, determining the molecular structure was not yet possible at that time.

In 1832, the two researchers worked together to formulate their so-called radical theory, which paved the way for modern organic chemistry. This stated that organic substances are composed of atom groups, which they called radicals. These remain unchanged during chemical reactions and are merely exchanged between the reactants. Although the term «radical» now has a different meaning in chemistry, a very similar principle remains until today: functional groups.

Superphosphate revolutionizes agriculture

Around 1840, Liebig, who had studied at the Sorbonne in Paris under such great names as Gay-Lussac and experienced France’s symbiotic relationship between science and industry, turned his back on fundamental research. Instead, he began studying organic chemistry in physiology and agriculture. He realized that plants extract nutrients needed for growth from the ground – with the exception of carbon dioxide, sourced from the air. From his findings, he deduced practical implications which revolutionized agriculture. Through his work, Liebig was the first to establish the need for fertilizer from a scientific point of view. His research also allowed him to determine which nutrients need to be present in fertilizer. This included simple organic compounds, but also inorganic substances such as salts. Based on this knowledge, Liebig developed the first artificial fertilizer, superphosphate, which led to an enormous increase in agricultural yields.

Liebig’s superphosphate fertilizer is still used today. Thanks to new findings, however, there are now a multitude of fertilizers which can provide the necessary nutrients based on the plants and soil conditions.

You can find several free Metrohm applications for agrochemicals available for download here:

Kekulé: dreamer or fibber?

Liebig’s students carried on his legacy through conducting fundamental chemical research. One such example is August Kekulé (1829–1896), who was inspired by Liebig to study chemistry during his time at the University of Giessen instead of becoming an architect as Kekulé’s family had envisaged. In 1858, Kekulé recognized the ability of carbon atoms to bond directly with one another to form chains. This explained how the few elements found in organic matter could form such a diversity of organic substances. In 1865, Kekulé also published findings on the structure of benzene.

According to his own statements, both of Kekulé’s groundbreaking ideas were inspirations from dreams – but the truth behind this is disputed. Kekulé is regarded as an intellectual who disparaged the culture prevailing among chemists and industrialists at the time: a pragmatic, positivistic way of thinking was spreading – it was a blind sense of empiricism which afforded no room for imagination. Christoph Meinel – a historian of chemical sciences – doubts the truth behind the dream anecdote, first told by Kekulé during a speech at a celebration in his honor. He states: «Kekulé’s ambivalent attitude toward the mentality present during this historical period, known as the ‹Gründerzeit›, and toward the patriarchal views of Berlin society resonates only too clearly in his speech. When Kekulé finishes narrating his vision with the words ‹Let’s learn to dream, gentlemen!›, the irony is very difficult to ignore given the prominent profile of those in attendance, who represented Prussian bureaucracy, Gründerzeit industries, and the elitist universities of the time» [1].

Artificial colors: All thanks to benzene

Regardless of whether Kekulé’s anecdote was based on true events or not, his discovery of the benzene structure and its importance to chemistry cannot be denied. Knowledge of organic and aromatic structures enabled systematic synthesis of the same molecules. The work of chemists was increasingly shifting from the isolation of substances from nature to the synthesis of artificial substances. The colorant industry experienced a boom after the discovery of the benzene structure, as this meant that a multitude of artificial colors could now be produced. Indigo production, for example, became an economically significant industrial process.

Colorant syntheses have not lost relevance since their invention in around 1900 – in fact, quite the opposite case. Colorants have been continuously developed for numerous properties and functions. This makes them inherently more complex than their primitive predecessors.

You can find out which analysis technique you need to monitor colorant properties on our industry page «Chemical» under the menu item «Solvents and colorants»: 

Check out the blog next week for the final installment of the series to learn about the advancements of chemistry around World War II.

Reference

[1] Sponsel, R. and Rathsmann-Sponsel, I. Kekulés Traum. Über eine typisch-psychoanalytische Entgleisung Alexander Mitscherlichs über den bedeutenden Naturwissenschaftler und Chemiker August Kekulé (1829-1896), Mitschöpfer der Valenz-, Vollender der Strukturtheorie und Entdecker der Bedeutung des Benzolrings. Alternative Analyse und Deutung aus allgemeiner und integrativer psychologisch-psychotherapeutischer Sicht. http://www.sgipt.org/th_schul/pa/kek/pak_kek0.htm (accessed Aug 15, 2016).

Post written by Dr. Alyson Lanciki, Scientific Editor at Metrohm International Headquarters, Herisau, Switzerland. Primary research and content contribution done by Stephanie Kappes.