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Recipes with Raman

Recipes with Raman

Many of us have spent more time in the kitchen in the past year than usual, (re)discovering our culinary skills with varying degrees of success. Our pantries have been kept full, and our stoves on for a year (and counting) since our normal, social ways of life have been curtailed by home office regulations, online schooling, and the sweeping closures of bars and restaurants.

Cooking at home can mean a number of things. Some people rely on «Chef Mike» (i.e., the microwave) to prepare their meals, while others turn humble ingredients into haute cuisine dishes. However, most people would probably agree that the keys to delicious and nutritious meals are fresh, high quality ingredients.

What is on your menu today? For breakfast, perhaps toast and some fresh pressed orange juice, lunch is maybe a quiche with tomatoes and cheese, and for dinner, stir-fried vegetables accompanied by a glass of good wine. Hungry yet?

With all of this talk about food, how can you be certain that the ingredients you are using in the kitchen are of the highest quality? You may trust in the grocery store, the brand, or the farmer at your local market, but do you know how different food quality parameters are measured?

One technique provides rapid, non-destructive and specific food quality testing: Raman spectroscopy. Whether you are looking to determine the ripeness of fruits or vegetables, the adulteration of spices or dairy products, or contamination of foods with banned pesticides, Raman spectroscopy is at the cutting edge of food quality analysis.

If you want to refresh your knowledge about Raman spectroscopy, have a look at our previous blog post about Mira, which includes some history about the technique.

To learn more about the analysis of trace adulterants in foods and beverages, read our blog post all about measurement with SERS (surface‐enhanced Raman scattering).

Are you confused about the differences between Raman spectroscopy and SERS? You’re not alone! Check out our blog post about these two techniques and learn about their benefits.

Here, we share a selection of peer-reviewed articles from the scientific community using Raman spectroscopy and portable instrumentation from B&W Tek, a Metrohm Group Company and Metrohm Raman to address quality issues of food. Enjoy your meal! Bon appetit!

~~ Starter ~~

To begin, maybe you would be interested in sharing a bottle of red wine with your companion as you snack on some crispy bread sticks. Red wines are made from red varieties of grapes, whose color is imparted through the crushing process as the skins soak in the sugary juices. Phenolic compounds derived from the grape skins can be beneficial to human health, and can be determined with Raman spectroscopy [1].

It’s not only beneficial compounds but also harmful contaminants that can be measured in beverages with Raman spectroscopy. Fungicides can also be detected in wine with SERS. Download our free Application Note if you want to find out more.

Watch our video below to see how methanol in alcoholic drinks is quantified rapidly without sample preparation – right at the bottle!

Snacking on prepackaged foods when you are on the go, or when you don’t feel like cooking at the moment, is something we have all done. The moisture levels in most of these foods is kept to a minimum, especially in those meant to have long shelf lives. Water content above certain levels allows harmful bacteria to grow, which is one of the major reasons to always consult the date of packaged foods before consumption. Eating contaminated foods can cause severe sickness and even death. It is possible to determine whether such low moisture foods (LMFs) contain harmful levels of these bacteria with SERS [2].

What else do both of these applications have in common? Both of them utilize the portable i-Raman Plus instrument from B&W Tek. For more information, download our free application note: Portable Raman for Quantification of Methanol in Contaminated Spirits.

~~Main Course~~

Depending on what you are in the mood for, anything is possible. Some tomatoes, vegetables, spices, perhaps meat (if you eat it) and a starch are on the menu today, ready to be turned into almost any dish.

Determining whether fresh foods are at peak ripeness can be a tricky process, not necessarily just the change of a color. The ripeness of a fruit or vegetable indicates its antioxidant content, as well as nutrients and other beneficial compounds. Monitoring the ripening process is possible with portable Raman spectroscopy [3], such as the B&W Tek i-Raman Pro.

Some of us like a little heat in our meals. Unfortunately, the adulteration of spices like chili powder (sometimes known as cayenne powder) is common, as cheap and harmful coloring agents are added to achieve more profits at the cost of human health. These synthetic dyes are able to be determined easily even at trace levels with SERS [4].

Download our free Application Note to learn more about the detection of trace levels of Rhodamine B in cayenne powder with SERS.

Some types of cheese command a high price for what seems like just a small pinch. One such type is Parmigiano Reggiano, an Italian cheese with a protected denomination of origin (PDO) quality marker, made in compliance with several production rules. These cheeses are subject to counterfeiting, but luckily this is easy to determine on-site without damaging the sample using handheld Raman spectroscopy [5].

The price of meat varies according to several reasons, even for the same animal source, section (cut), and portion size. Among these is the origin of the meat, as well as how it was produced (e.g., organic or a factory farm). Determining the difference between premium meat products and lower quality ones is possible with handheld Raman systems [6] such as Mira from Metrohm Raman. Not only these differences but also the freshness of meat during the production process can be measured with portable Raman devices [7] like the i-Raman Plus from B&W Tek.

Using lower quality cooking oil with a low smoke point at high temperatures can result in consumption of harmful byproducts formed during cooking. Older oils have a lower antioxidant content as a result of the aging process, and can become rancid when the antioxidant properties vanish. For these reasons, high quality edible oils full of antioxidants are worth much more, but are also susceptible to adulteration with cheaper ingredients. It is possible to not only determine the purity of edible oils by Raman spectroscopy [8] but also the heat stability of different types of oils [9].

For more information about the analysis of edible oils by Raman spectroscopy, download our free Application Notes and our White Paper below!

~~ Dessert ~~

After dinner is over, a hot beverage like tea can be nice to cleanse the palate. How can you be sure that the tea is free of banned pesticides, other than buying from a trusted organic label? SERS allows rapid identification of such substances in tea leaves [10].

To learn more about detecting illegal compounds such as herbicides on tea leaves, download our free Application Note.

The honey you put in your tea or drizzle over your dessert can also be subjected to tampering. Depending on the type of flower or the origin of the honey, costs can vary widely for the same volume. Some honeys (e.g., Manuka) claim to impart certain health benefits, and therefore many lower quality products with cheap sweeteners (e.g., high fructose corn syrup) are falsely labeled as such and sold at a higher price point to unsuspecting consumers. It is possible to detect honey adulteration [11] and even its botanical origin [12] with Raman spectroscopy.

Not only tea and honey, but also coffee and the milk added to it can be analyzed with Raman spectroscopy to determine various quality markers and adulterants.

The protein content of milk can be falsely enhanced with the addition of melamine. This compound is now monitored in dairy products due to scandals which led to deaths from kidney damage. Melamine [13] and other substances which can contribute to ill health effects [14] can be easily determined in milk with SERS.

Want to learn more about Melamine and how to measure it with SERS? Check out our free Application Note for further information.

Download our free Application Note to learn about the rapid detection of the alkaloid trigonelline in coffee, which reduces in concentration the darker the beans are roasted.

The ripeness of fruits and vegetables is not just important information when planning meals, but it is also critical for food transport. Perishable fruits and vegetables are often shipped in an unripened state so they arrive at their destination in top condition.

Freshness in citrus fruits can be determined with portable Raman instruments by measuring the carotenoid content [15].

Aside from the freshness, it is also possible to detect if pesticides, fungicides, herbicides or other harmful substances have been sprayed onto fruits using SERS [16].

Check out our selection of free Application Notes below about the determination of these kinds of substances on different fruits with Misa.

Several food quality parameters can be measured quickly and easily with Raman spectroscopy without the need to open bottles or destroy samples. Portable and handheld instruments make measurements simple to perform nearly anywhere. Visit the Metrohm website to learn more about the possibilities with Raman!

Learn more about rapid food analysis with Raman spectroscopy

Download free applications directly from our website.


[1] Dranca, F.; Oroian, M. Kinetic Improvement of Bioactive Compounds Extraction from Red Grape (Vitis vinifera Moldova) Pomace by Ultrasonic Treatment. Foods 2019, 8, 353. doi:10.3390/foods8080353

[2] Pan, C.; Zhu, B.; Yu, C. A Dual Immunological Raman-Enabled Crosschecking Test (DIRECT) for Detection of Bacteria in Low Moisture Food. Biosensors 2020, 10, 200. doi:10.3390/bios10120200

[3] Trebolazabala, J.; Maguregui, M.; Morillas, H.; et al. Portable Raman spectroscopy for an in-situ monitoring the ripening of tomato (Solanum lycopersicum) fruits. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2017, 180, 138–143. doi:10.1016/j.saa.2017.03.024

[4] Lin, S.; Hasi, W.-L.-J.; Lin, X.; et al. Rapid and sensitive SERS method for determination of Rhodamine B in chili powder with paper-based substrates. Analytical Methods 2015, 7, 5289–5294. doi:10.1039/c5ay00028a

[5] Li Vigni, M.; Durante, C.; Michelini, S.; et al. Preliminary Assessment of Parmigiano Reggiano Authenticity by Handheld Raman Spectroscopy. Foods 2020, 9(11), 1563. doi:10.3390/foods9111563

[6] Logan, B.; Hopkins, D.; Schmidtke, L.; et al. Authenticating common Australian beef production systems using Raman spectroscopy. Food Control 2021, 121, 107652. doi:10.1016/j.foodcont.2020.107652

[7] Santos, C; Zhao, J.; Dong, X.; et al. Predicting aged pork quality using a portable Raman device. Meat Science 2018, 145, 79–85. doi:10.1016/j.meatsci.2018.05.021

[8] Liu, Z.; Yu, S.; Xu, S.; et al. Ultrasensitive Detection of Capsaicin in Oil for Fast Identification of Illegal Cooking Oil by SERRS. ACS Omega 2017, 2, 8401–8406. doi:10.1021/acsomega.7b01457

[9] Alvarenga, B.; Xavier, F.; Soares, F.; et al. Thermal Stability Assessment of Vegetable Oils by Raman Spectroscopy and Chemometrics. Food Analytical Methods 2018, 11, 1969–1976. doi:10.1007/s12161-018-1160-y

[10] Yao, C.; Cheng, F.; Wang, C.; et al. Separation, identification and fast determination of organophosphate pesticide methidathion in tea leaves by thin layer chromatography–surface-enhanced Raman scattering. Analytical Methods 2013, 5, 5560. doi:10.1039/c3ay41152d

[11] Li, S.; Shan, Y.; Zhu, X.; et al. Detection of honey adulteration by high fructose corn syrup and maltose syrup using Raman spectroscopy. Journal of Food Composition and Analysis 2012, 28, 69–74. doi:10.1016/j.jfca.2012.07.006

[12] Oroian, M.; Ropciuc, S. Botanical authentication of honeys based on Raman spectra. Journal of Food Measurement and Characterization 2017, 12, 545–554. doi:10.1007/s11694-017-9666-3

[13] Nieuwoudt, M.; Holroyd, S.; McGoverin, C.; et al. Rapid, sensitive, and reproducible screening of liquid milk for adulterants using a portable Raman spectrometer and a simple, optimized sample well. Journal of Dairy Science 2016, 99, 7821–7831. doi:10.3168/jds.2016-11100

[14] Lin, X.; Hasi, W.-L.-J.; Lou, X.-T.; et al. Rapid and simple detection of sodium thiocyanate in milk using surface-enhanced Raman spectroscopy based on silver aggregates. Journal of Raman Spectroscopy 2014, 45, 162–167. doi:10.1002/jrs.4436

[15] Nekvapil, F.; Brezestean, I.; Barchewitz, D.; et al. Citrus fruits freshness assessment using Raman spectroscopy. Food Chemistry 2018, 242, 560–567. doi:10.1016/j.foodchem.2017.09.105

[16] Xie, J.; Li, L.; Khan, I.; et al. Flexible paper-based SERS substrate strategy for rapid detection of methyl parathion on the surface of fruit. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2020, 231, 118104. doi:10.1016/j.saa.2020.118104

Post written by Dr. Sara Seiffert (Product Specialist Spectroscopy at Metrohm Deutschland) and Dr. Alyson Lanciki (Scientific Editor at Metrohm International Headquarters).

Raman vs SERS… What’s the Difference?

Raman vs SERS… What’s the Difference?

If you’ve ever had a conversation with a Raman spectroscopist about the feasibility of a low-concentration sensing application, chances are you’ve heard them say “well, Raman may not be sensitive enough…but maybe SERS will work!” But what’s the actual difference between these two techniques, and why is SERS (surface-enhanced Raman scattering, or alternatively surface-enhanced Raman spectroscopy) recommended for low-concentration applications? Let’s explore the technical differences between Raman and SERS spectroscopies, as well as some of the practical considerations for how we regard the data for each.

In normal Raman spectroscopy, a laser source is incident directly on a sample (Fig. 1a). The laser light is scattered by the bonds of the analyte, and the inelastically scattered light is collected and processed into a Raman spectrum. The non-destructive nature of the technique, the selectivity of Raman bands, and the insensitivity to water make Raman a useful analytical tool for both qualitative and quantitative studies of both organic and inorganic systems.

Figure 1. 

However, for decades Raman spectroscopy was an underutilized technique in real-world applications. This can be attributed to its two major limitations: 1) the inherent insensitivity of Raman, as only ~1 in 106 incident photons are Raman scattered; and 2) fluorescence emission interference, which depends on the nature of the analyte molecule and the excitation wavelength used. Fluorescence is a competing phenomenon that is much more efficient than Raman scattering, and can thus completely overwhelm the Raman signal.

Though they depend on the scattering strength of the analyte molecule and the sample matrix in question, typical limits of detection for normal Raman scattering can range from ~1–10% in concentration. For certain applications such as disease detection or narcotics identification, this limit may be several orders of magnitude higher than what is required! In this case, an application scientist might recommend a SERS measurement. The hardware required would be the same as for a normal Raman measurement, but different sampling is required for SERS analysis. To understand the difference, let’s discuss a bit about the SERS effect.

In the 1970s, several research groups observed that the Raman signal from organic molecules like pyridine was greatly enhanced when adsorbed to a roughened metallic substrate (Fig. 1b) [1–3]. While several theories emerged to account for this observation, it is today generally accepted that the mechanism for enhancement is two-fold: the electromagnetic enhancement mechanism accounts for the dominant contribution, while a chemical mechanism accounts for a smaller portion of the enhancement.

Figure 2.

The electromagnetic enhancement mechanism is enabled by the use of a roughened nanometallic substrate made of a noble metal (usually silver or gold), and the presence of localized surface plasmons, which are quantized oscillations of the valence electrons of the chosen metal. When the laser excites the sample/nanosubtrate complex, it drives the localized surface plasmons into resonance, or excites the “LSPR” (Fig. 2). At this condition, both the laser excitation radiation and the scattered radiation from the sample are amplified. The arrows in Fig. 1b are bolded to show this increase in magnitude. This mechanism can theoretically account for signal enhancement by factors as large as 1011 [4]. The chemical mechanism involves charge-transfers in resonance with the laser excitation wavelength, and typically accounts for a theoretical enhancement factor of up to 104 [5]. Interfering fluorescence can also be quenched by these charge transfers. With the combined enhancement mechanisms we are able to overcome both the inherent insensitivity and fluorescence interference that limits normal Raman scattering. In fact, there are studies which have demonstrated that SERS is able to detect single molecules [6,7]!

Fabrication of these nanostructures has been an increasing area of academic research in the last two decades. SERS substrates can include colloidal suspensions, solid nanospheres, and metal coated on silicon chips. The enhancement tends to be at its height when the analyte molecule is placed at a junction of nanostructures (otherwise known as a SERS “hotspot”), so researchers can tailor the shapes and the plasmonic activity of these substrates to reach even greater levels of enhancement for their research purposes.

There are also commercial SERS substrates that are available for purchase to use for real-world applications. These substrates are designed to be easy-to-use, flexible, and low-cost, but may not be as sensitive as highly ordered substrates. We offer both a paper-based SERS substrate and a chip-based SERS substrate mounted to a glass slide.

After discussion with an application scientist, users may determine that a commercially available SERS substrate is suitable for their application. However, in others greater sensitivity may be required to meet the limits of detection for the application. In this case, local university labs who work on nanofabrication may be able to collaborate on measurements.

Figure 3.

We often get questions such as “Can we use our existing Raman reference library to analyze our SERS spectrum?” Figure 3 shows the difference between a normal Raman spectrum of fentanyl HCl (Fig. 3a), and a SERS spectrum of a saturated solution of fentanyl HCl on a commercial SERS substrate (Fig. 3b). The normal Raman spectrum for fentanyl contains significantly more peaks than the corresponding SERS spectrum. The SERS bands are also noticeably broader than the normal Raman bands. In the case of the SERS spectra, it is not solely the vibrational modes of the molecule that are being probed, but the sample as adsorbed to the substrate. Hence, we may also observe some peaks in a SERS spectrum that can be attributed purely to the substrate. Because of the differences between a SERS spectrum and a normal Raman spectrum, it may be difficult in some cases to use commercial Raman libraries for analysis of SERS spectra. We encourage users who require SERS identification to create their own SERS spectral databases using their substrates. We also include SERS-specific narcotics libraries on some of our TacticID handheld Raman products. For more complicated data analysis, there is also an expansive SERS literature base to draw on.

In low-concentration sensing applications, or instances where fluorescence overwhelms your Raman signal, SERS is an invaluable technique for both researchers and real-world problem solvers alike. For more information, visit our website.

Learn more about SERS

Download free applications, white papers, and more from our website.


[1] D.L. Jeanmaire and R.P. Van Duyne, J. Electroanal, Chem84, 1–20 (1977).
[2] M.FleischmannP.J.Hendra, and A.J. McQuillanChem. Phys. Lett. 26, 163-166 (1974).
[3] M.G. Albrecht and J.A. Creighton, J. Am. Chem. Soc. 99, 5215-5217 (1977).
[4] J.P  Camden J. A. DieringerY. WangD.J. MasielloL.D. MarksG.C. Schatz, and R.P. Van DuyneJ. Am. Chem. Soc. 130, 12616–12617 (2008).
[5] R. Pilot, R. Signorini, and L Fabris, “Surface-Enhanced Raman spectroscopy: Principles, Substrates, and Applications”. In: Deepak F.L., editor. Metal Nanoparticles and Clusters: Advances in Synthesis, Properties and Applications. Springer; Cham, Switzerland: 2018. pp. 89–164.
[6] J.A. Dieringer, R.B. Lettan, K.A. Scheidt, and R.P Van Duyne, J. Am. Chem. Soc.129, 16249–16256 (2007).
[7] K. Kneipp, Y. Wang, H. Kneipp, L.T. Perelman, I. Itzkan, R.R. Dasari, and M.S. Feld, Phys. Rev. Lett. 78, 1667-1670 (1997).

Post written by Kristen Frano, Applications Manager at B&W Tek, Newark, DE, USA.

Introduction to Analytical Instrument Qualification – Part 2

Introduction to Analytical Instrument Qualification – Part 2

Welcome back to our blog, and happy 2021! We hope that you and your families had a safe and restful holiday season. To start the year, we will conclude our introduction to Analytical Instrument Qualification. 

Metrohm’s approach to Analytical Instrument Qualification (AIQ)

Metrohm’s answer to Analytical Instrument Qualification is bundled in our Metrohm Compliance Services. The most thorough level of documentation offered for AIQ is the IQ/OQ.

Metrohm IQ/OQ documentation provides you with the required documentation in strict accordance to the major regulations from the USP, FDA, GAMP, and PIC/S, allowing you to document the suitability of your Metrohm instruments for your lab’s specific intended use.

With our test procedures (described later in more detail), we can prove that the hardware and software components function correctly, both individually and as part of the system as a whole. With Metrohm’s IQ/OQ, you are supported in the best possible way to integrate our systems into your current processes.

Our high quality documentation will have you «audit ready» all the time.

The flexibility of a modular document structure

Depending on the environment you work in and your specific demands, Metrohm can offer a tailored qualification approach thanks to documentation modularity. If you need a lower level of qualification, only the required modules can be executed. Our documentation consists of different modules, each of which documents the identity of the Metrohm representative along with the qualification reviewer, combined with the details of each instrument, software, and document involved in the qualification.  Thanks to this, each module is independent, which guarantees both full traceability and reliability for your system setup.

Cost-effective qualification from Metrohm

Metrohm supports you by implementing a cost-effective qualification process, depending upon your requirements and the modules needed. This means that a qualification is not about performing unnecessary actions, qualification is about completing the required work.

The risk assessment analysis defines the level of qualification needed and based on it, we focus on testing only what needs to be tested. In case you relocate your device to another lab, which qualification steps (DQ, IQ, OQ, PQ) are really needed in order to fulfill your requirements? Contact your local Metrohm expert for advice on this matter.

A complete Metrohm IQ/OQ qualification includes…

Metrohm IQ/OQ documentation is based on the following documentation tree, beginning with the first module, the Master Document (MD), followed by the Installation Qualification (IQ) and eventually the Operational Qualification (OQ). The OQ is then divided again into individual component tests (Hardware and Software) and a holistic test to validate your complete system.

Master Document (MD)

Each qualification starts with the Master Document (MD) – the central organizing document for the AIQ procedures. It not only describes the process of installing and qualifying the instruments, but also the competence and education level of the qualifying engineer. The MD identifies all other components to be added to the qualification, resulting in a flexible framework on which to build up a set of documentation.

Installation Qualification (IQ)

Once the content of the documentation is defined in the MD, the Installation Qualification (IQ) follows. This set of documentation is designed to ensure that the instrument, software, and any accessories have been all delivered and installed correctly. The IQ protocol additionally specifies that the workplace is suitable for the analytical system as stipulated by Metrohm.

Operational Qualification (OQ)

After a correct installation comes the main part of the qualification: the Operational Qualification (OQ). In the first part of the OQ, the functionality of the single hardware components is tested and evaluated according to a set of procedures. This is to ensure that the instrument is working perfectly as designed, and is safe to use. Rest assured that you can rely on the expertise of our Metrohm certified engineers to conduct these comprehensive tests on your instruments using the necessary calibrated and certified tools.

The second part of the OQ consists of a set of Software Tests to prove that the installed Metrohm software functions correctly and reliably on the computer it was installed on. The importance of maintaining software in a validated state is also related to the data integrity of your laboratory. Therefore these software tests can be repeated periodically or after major changes. In particular, these functionality tests cover verifications on user management, database functionalities, backups, audit trail review, security policy, electronic signatures, and so on.

At Metrohm, we constantly work to improve our procedures and use state of the art tools and technologies.  For this reason, we have implemented a completely automated test procedure for validating the software of our new OMNIS platform. This ensures full integrity in the execution and delivers consistent results with a faster and completely error-free test execution. This innovative and automated software validation eliminates manual activities that are labor intensive and time consuming. This therefore expedites testing and removes the inefficiencies that plague the paper-based software validation.

Your benefit is clear: save valuable time and reduce unnecessary laboratory start-up activities during qualification. That’s time you can spend on other work in your lab!

Holistic Test (Performance Verification, PV)

Once each individual component has been separately tested, the performance of the system as a whole is proven by means of a holistic test (OQ-PV).

This includes a series of «wet-chemical» tests, performed using certified reference materials, to prove the system is capable of generating quality data, i.e. results that are accurate, precise, and above all fit for purpose. Based on detailed, predefined instructions (SOPs), a series of standard measurements are performed, statistically evaluated, and compared to the manufacturer’s specifications.

Differences between Performance Verification (PV) and Performance Qualification (PQ)

The Performance Verification (PV) is a set of tests offered by Metrohm in order to verify the fitness for purpose of the instrument. As mentioned in the previous paragraph, the PV includes standardized test procedures to ensure the system operates as designed by the manufacturer in the selected environment.

On the other hand, the Performance Qualification (PQ) is a very customer specific qualification phase (see the «4 Q’s» Qualification Phases found in Part 1). PQ verifies the fitness for purpose of the instrument under actual condition of use, proving its continued suitability. Therefore, PQ tests are defined depending on your specific analysis and acceptance criteria.

Now my questions to you—is your analytical instrument qualified for its intended use? Is your lab in compliance with the latest regulations for equipment qualification and validation? Get expert advice directly from your local Metrohm agency and request your quote for Metrohm qualification services today!

Check out our online material:

Metrohm Quality Service

Post written by Lara Casadio, Jr. Product Manager Service at Metrohm International Headquarters, Herisau, Switzerland.

«Analyze This»: 2020 in review

«Analyze This»: 2020 in review

I wanted to end 2020 by thanking all of you for making «Analyze This» – the Metrohm blog for chemists such a success! For our 60th blog post, I’d like to look back and focus on the wealth of interesting topics we have published this year. There is truly something for everyone: it doesn’t matter whether your lab focuses on titration or spectroscopic techniques, or analyzes water samples or illicit substances – we’ve got you covered! If you’re looking to answer your most burning chemical analysis questions, we have FAQs and other series full of advice from the experts. Or if you’re just in the mood to learn something new in a few minutes, there are several posts about the chemical world to discover.

We love to hear back from you as well. Leaving comments on your favorite blog posts or contacting us through social media are great ways to voice your opinion—we at Metrohm are here for you!

Finally, I wish you and your families a safe, restful holiday season. «Analyze This» will return on January 11, 2021, so subscribe if you haven’t already done so, and bookmark this page for an overview of all of our articles grouped by topic!

Stay healthy, and stay curious.

Best wishes,

Dr. Alyson Lanciki, Scientific Editor, Metrohm AG

Quickly jump directly to any section by clicking a topic:

Customer Stories

We are curious by nature, and enjoy hearing about the variety of projects where our products are being used! For some examples of interesting situations where Metrohm analytical equipment is utilized, read on.

From underwater archaeological research to orbiting Earth on the International Space Station, Metrohm is there! We assist on all types of projects, like brewing top quality beers and even growing antibiotic-free shrimp – right here in Switzerland.

Interested in being featured? Contact your local Metrohm dealer for details!


Metrohm is the global market leader in analytical instruments for titration. Who else is better then to advise you in this area? Our experts are eager to share their knowledge with you, and show this with the abundance of topics they have contributed this year to our blog.

For more in-depth information about obtaining the most accurate pH measurements, take a look at our FAQ about pH calibration or read about avoiding the most common mistakes in pH measurement. You may pick up a few tips!

Choose the best electrode for your needs and keep it in top condition with our best practices, and then learn how to standardize titrant properly. Better understand what to consider during back-titration, check out thermometric titration and its advantages and applications, or read about the most common challenges and how to overcome them when carrying out complexometric titrations

If you are interested in improving your conductivity measurements, measuring dissolved oxygen, or the determination of oxidation in edible fats and oils, check out these blog posts and download our free Application Notes and White Papers!

Finally, this article about comprehensive water analysis with a combination of titration and ion chromatography explains the many benefits for laboratories with large sample loads. The history behind the TitrIC analysis system used for these studies can be found in a separate blog post.

Karl Fischer Titration

Metrohm and Karl Fischer titration: a long history of success. Looking back on more than half a century of experience in KFT, Metrohm has shaped what coulometric and volumetric water analysis are today.

Aside from the other titration blog posts, our experts have also written a 2-part series including 20 of the most frequently asked questions for KFT arranged into three categories: instrument preparation and handling, titration troubleshooting, and the oven technique. Our article about how to properly standardize Karl Fischer titrant will take you step by step through the process to obtain correct results.

For more specific questions, read about the oven method for sample preparation, or which is the best technique to choose when measuring moisture in certain situations: Karl Fischer titration, near-infrared spectroscopy, or both?

Ion Chromatography (IC)

Ion chromatography has been a part of the Metrohm portfolio since the late 1980s. From routine IC analysis to research and development, and from stand-alone analyzers to fully automated systems, Metrohm has provided IC solutions for all situations. If you’re curious about the backstory of R&D, check out the ongoing series about the history of IC at Metrohm.

Metrohm IC user sitting at a laboratory bench.

Common questions for users are answered in blog posts about IC column tips and tricks and Metrohm inline ultrafiltration. Clear calculations showing how to increase productivity and profitability in environmental analysis with IC perfectly complement our article about comprehensive water analysis using IC and titration together for faster sample throughput.

On the topic of foods and beverages, you can find out how to determine total sulfite faster and easier than ever, measure herbicides in drinking water, or even learn how Metrohm IC is used in Switzerland to grow shrimp!

Near-Infrared Spectroscopy (NIRS)

Metrohm NIRS analyzers for the lab and for process analysis enable you to perform routine analysis quickly and with confidence – without requiring sample preparation or additional reagents and yielding results in less than a minute. Combining visible (Vis) and near-infrared (NIR) spectroscopy, these analyzers are capable of performing qualitative analysis of various materials and quantitative analysis of a number of physical and chemical parameters in one run.

Our experts have written all about the benefits of NIR spectroscopy in a 4-part series, which includes an explanation of the advantages of NIRS over conventional wet chemical analysis methods, differences between NIR and IR spectroscopy, how to implement NIRS in your laboratory workflow, and examples of how pre-calibrations make implementation even quicker.

A comparison between NIRS and the Karl Fischer titration method for moisture analysis is made in a dedicated article.

A 2-part FAQ about NIRS has also been written in a collaboration between our laboratory and process analysis colleagues, covering all kinds of questions related to both worlds.

Raman Spectroscopy

This latest addition to the Metrohm family expands the Metrohm portfolio to include novel, portable instruments for materials identification and verification. We offer both Metrohm Raman as well as B&W Tek products to cover a variety of needs and requirements.

Here you can find out some of the history of Raman spectroscopy including the origin story behind Mira, the handheld Raman instrument from Metrohm Raman. For a real-world situation involving methamphetamine identification by law enforcement and first responders, read about Mira DS in action – detecting drugs safely in the field.

Mira - handheld Raman keeping you safe in hazardous situations.

Are you looking for an easier way to detect food fraud? Our article about Misa describes its detection capabilities and provides several free Application Notes for download.

Process Analytics

We cater to both: the laboratory and the production floor. The techniques and methods for laboratory analysis are also available for automated in-process analysis with the Metrohm Process Analytics brand of industrial process analyzers.

Learn about how Metrohm became pioneers in the process world—developing the world’s first online wet chemistry process analyzer, and find out how Metrohm’s modular IC expertise has been used to push the limits in the industrial process optimization.

Additionally, a 2-part FAQ has been written about near-infrared spectroscopy by both laboratory and process analysis experts, which is helpful when starting out or even if you’re an advanced user.

Finally, we offer a 3-part series about the advantages of process analytical technology (PAT) covering the topics of process automation advantages, digital networking of production plants, and error and risk minimization in process analysis.

Voltammetry (VA)

Voltammetry is an electrochemical method for the determination of trace and ultratrace concentrations of heavy metals and other electrochemically active substances. Both benchtop and portable options are available with a variety of electrodes to choose from, allowing analysis in any situation.

A 5-part series about solid-state electrodes covers a range of new sensors suitable for the determination of «heavy metals» using voltammetric methods. This series offers information and example applications for the Bi drop electrode, scTrace Gold electrode (as well as a modified version), screen-printed electrodes, and the glassy carbon rotating disc electrode.

Come underwater with Metrohm and Hublot in our blog post as they try to find the missing pieces of the ancient Antikythera Mechanism in Greece with voltammetry.

If you’d like to learn about the combination of voltammetry with ion chromatography and the expanded application capabilities, take a look at our article about combined analysis techniques.

Electrochemistry (EC)

Electrochemistry plays an important role in groundbreaking technologies such as battery research, fuel cells, and photovoltaics. Metrohm’s electrochemistry portfolio covers everything from potentiostats/galvanostats to accessories and software.

Our two subsidiaries specializing in electrochemistry, Metrohm Autolab (Utrecht, Netherlands) and Metrohm DropSens (Asturias, Spain) develop and produce a comprehensive portfolio of electrochemistry equipment.

This year, the COVID-19 pandemic has been at the top of the news, and with it came the discussion of testing – how reliable or accurate was the data? In our blog post about virus detection with screen-printed electrodes, we explain the differences between different testing methods and their drawbacks, the many benefits of electrochemical testing methods, and provide a free informative White Paper for interested laboratories involved in this research.

Our electrochemistry instruments have also gone to the International Space Station as part of a research project to more efficiently recycle water on board spacecraft for long-term missions.

The History of…

Stories inspire people, illuminating the origins of theories, concepts, and technologies that we may have become to take for granted. Metrohm aims to inspire chemists—young and old—to be the best and never stop learning. Here, you can find our blog posts that tell the stories behind the scenes, including the Metrohm founder Bertold Suhner.

Bertold Suhner, founder of Metrohm.

For more history behind the research and development behind Metrohm products, take a look at our series about the history of IC at Metrohm, or read about how Mira became mobile. If you are more interested in process analysis, then check out the story about the world’s first process analyzer, built by Metrohm Process Analytics.

Need something lighter? Then the 4-part history of chemistry series may be just what you’re looking for.

Specialty Topics

Some articles do not fit neatly into the same groups as the rest, but are nonetheless filled with informative content! Here you can find an overview of Metrohm’s free webinars, grouped by measurement technique.

If you work in a regulated industry such as pharmaceutical manufacturing or food and beverage production, don’t miss our introduction to Analytical Instrument Qualification and what it can mean for consumer safety!


Finally, if you are more interested in reading articles related to the industry you work in, here are some compilations of our blog posts in various areas including pharmaceutical, illicit substances, food and beverages, and of course water analysis. More applications and information can be found on our website.

Food and beverages
All of these products can be measured for total sulfite content.

Oxidation stability is an estimate of how quickly a fat or oil will become rancid. It is a standard parameter of quality control in the production of oils and fats in the food industry or for the incoming goods inspection in processing facilities. To learn more about how to determine if your edible oils are rancid, read our blog post.

Determining total sulfite in foods and beverages has never been faster or easier than with our IC method. Read on about how to perform this notoriously frustrating analysis and get more details in our free LC/GC The Column article available for download within.

Measuring the true sodium content in foodstuff directly and inexpensively is possible using thermometric titration, which is discussed in more detail here. To find out the best way to determine moisture content in foods, our experts have written a blog post about the differences between Karl Fischer titration and near-infrared spectroscopy methods.

To determine if foods, beverages, spices, and more are adulterated, you no longer have to wait for the lab. With Misa, it is possible to measure a variety of illicit substances in complex matrices within minutes, even on the go.

All of these products can be measured for total sulfite content.

Making high quality products is a subject we are passionate about. This article discusses improving beer brewing practices and focuses on the tailor-made system built for Feldschlösschen, Switzerland’s largest brewer.

Pharmaceutical / healthcare

Like the food sector, pharmaceutical manufacturing is a very tightly regulated industry. Consumer health is on the line if quality drops.

Ensuring that the analytical instruments used in the production processes are professionally qualified is a must, especially when auditors come knocking. Find out more about this step in our blog post about Analytical Instrument Qualification (AIQ).

Moisture content in the excipients, active ingredients, and in the final product is imperative to measure. This can be accomplished with different analytical methods, which we compare and contrast for you here.

The topic of virus detection has been on the minds of everyone this year. In this blog post, we discuss virus detection based on screen-printed electrodes, which are a more cost-effective and customizable option compared to other conventional techniques.

Water analysis

Water is our business. From trace analysis up to high concentration determinations, Metrohm has you covered with a variety of analytical measurement techniques and methods developed by the experts.

Learn how to increase productivity and profitability in environmental analysis laboratories with IC with a real life example and cost calculations, or read about how one of our customers in Switzerland uses automated Metrohm IC to monitor the water quality in shrimp breeding pools.

If heavy metal analysis is what you are interested in, then you may find our 5-part series about trace analysis with solid-state electrodes very handy.

Unwanted substances may find their way into our water supply through agricultural practices. Find out an easier way to determine herbicides in drinking water here!

Water is arguably one of the most important ingredients in the brewing process. Determination of major anions and cations along with other parameters such as alkalinity are described in our blog post celebrating International Beer Day.

All of these products can be measured for total sulfite content.
Illicit / harmful substances

When you are unsure if your expensive spices are real or just a colored powder, if your dairy products have been adulterated with melamine, or fruits and vegetables were sprayed with illegal pesticides, it’s time to test for food fraud. Read our blog post about simple, fast determination of illicit substances in foods and beverages for more information.

Detection of drugs, explosives, and other illegal substances can be performed safely by law enforcement officers and first responders without the need for a lab or chemicals with Mira DS. Here you can read about a real life training to identify a methamphetamine laboratory.

Drinking water regulations are put in place by authorities out of concern for our health. Herbicides are important to measure in our drinking water as they have been found to be carcinogenic in many instances.

Post written by Dr. Alyson Lanciki, Scientific Editor at Metrohm International Headquarters, Herisau, Switzerland.

Introduction to Analytical Instrument Qualification – Part 2

Introduction to Analytical Instrument Qualification – Part 1

When talking about the subject of Analytical Instrument Qualification (AIQ), my first thought is of regulated industries, like pharmaceuticals and food. 

You may be wondering—Why do we need to qualify analytical instruments in this environment? Why does my titrando or my OMNIS system need such a service?

Consumer safety here is of paramount importance. Medicines that may represent a health hazard for patients or do not provide the intended therapeutic effect are undesirable and costly, therefore steps must be taken to safeguard the manufacturing process and prevent fatal implications. By qualifying the used analytical instruments, we can ensure that active ingredients and finished pharmaceutical products are manufactured in a safe environment.

In addition, procedures that prove instrument accuracy and repeatability are a must. Metrohm qualification procedures provide this documentation, fully traceable evidence which is also required for inspections and audits by regulatory authorities.

When auditors come knocking

In case an auditor observes any violations of the United States Food and Drug Administration (FDA) guidelines for example, this will be communicated in an inspectoral observation or a Warning Letter. If we look to pharmaceutical Warning Letters in the past, we can see that the FDA is mainly concerned with issues related to qualification and data integrity.

Some typical findings are e.g. the usage of an unqualified system, or the use of an instrument outside of the calibration range for which it was initially qualified. This proves the point that qualification of analytical instruments in regulated environments cannot be ignored.

Metrohm Compliance Services can help to prove the full data traceability of your qualification activities, simplifying your audit preparation and at the same time maintaining a constant state of inspection readiness for your laboratory.

Instruments in regulated environments need to be qualified periodically according to the main regulatory bodies. The United States Pharmacopeia (USP) is the leading pharmacopeia that has a general chapter dedicated to Analytical Instrument Qualification (AIQ), USP <1058>. Therefore, it has global significance, making laboratories subject to regulatory requirements either directly or indirectly. This is why Metrohm Compliance Services are based on this important chapter.

What is Analytical Instrument Qualification (AIQ) exactly?

As per USP <1058>, it is «the collection of documented evidence that an instrument performs suitably for its intended purpose.» This indicates that AIQ is the foundation for generating quality data with the needed data integrity. By using qualified instruments, you gain confidence in the validity of generated data and that your instrument meets specifications of regulatory standards.

AIQ is not a single activity, but a continuous process over the lifetime of the instrument. AIQ already starts before the instrument purchase with the formal writing of User Requirement Specifications (URS), where the lab’s requirements for a specific instrument are documented. And yes, for e.g. a fully equipped Metrohm Dual IC system as well as for a single Metrohm pH meter, there is the same need to document the laboratory requirements and its intended use.

After clarification of the intended use and the evaluation of the right technology, a Risk Assessment (RA) needs to be carried out to determine the required qualification strategy to prove the «fitness for purpose» of the purchased analytical instrument.

The extent of the next qualification stages depends on the outcome of the Risk Assessment. The following activities are grouped into four phases: Design Qualification (DQ), Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ), the so-called «4 Q’s».

Whereas the DQ is the documented verification that the instrument specifications meet the laboratory requirements, the IQ provides the proof that the equipment has been installed properly. In the OQ phase, it’s demonstrated that the system operates correctly in the selected environment as per manufacturer specifications, while the PQ confirms that the instrument consistently performs according to your defined specifications.

During the lifecycle of the instrument, major repairs might be needed, it might be subject to major updates / upgrades, or it might even be transferred to another lab. In all of these cases, the original URS should be reviewed again and adjusted if necessary. The URS is a living document that can and must be changed and updated when needed. Based on a risk assessment analysis, it will then be defined what the qualification steps are that should be repeated after the needed changes (IQ, OQ, PQ).

Eventually the instrument’s life comes to an end, and we arrive at its retirement. This final step of the AIQ is often considered as the «forgotten child» of validation activities. To put this a bit more in perspective, consider when you make a new electronic purchase, such as a PC. The situation is similar to when a new analytical system is bought. It’s easier to focus on something new—concentrating on getting the training for its proper usage, and making sure it’s working correctly. We begin to ignore or forget that the old system is still there.

Therefore, decommissioning of an instrument is a critical part of the validation process that must also be very well documented. For the old system, a final system qualification might be necessary if required. Afterwards, all data have to be removed and stored in a safe location. It is extremely important to ensure that the data can be read from this location (data migration) for a number of years, depending on your retention procedures.

Support when and where you need it

The fact that users have responsibilities for the instrument qualification (USP <1058>) does not mean that all qualification activities must be conducted alone!

Metrohm supports you over the lifetime of your investment, from advising you during the purchase process to the first installation and qualification. Additionally, our IQ/OQ documentation provides you the required documentation in strict accordance with the current regulations. To ensure your Metrohm device remains in a qualified state, we offer requalification services at scheduled intervals as specified in your requirements, to guarantee the accuracy and precision of your system over its lifetime. 

An advantage of relying on Metrohm as the manufacturer of your analytical instruments is that we have all the necessary experience for performing IQ/OQ procedures. Most importantly, our certified service engineers bring along all calibrated and certified reference instruments that are required for the qualification. To ensure the quality of Metrohm Service is maintained, our service engineers undergo compulsory re-training on a regular basis according to a globally standardized program.

Buying Metrohm equipment is the first step to success, but maintaining it in a qualified state is the key! Just contact your local Metrohm dealer and let us handle the rest.

For more details about which qualification phases can be fully handled by Metrohm and where we can support you, read Part 2!

Check out our online material:

Metrohm Quality Service

Post written by Lara Casadio, Jr. Product Manager Service at Metrohm International Headquarters, Herisau, Switzerland.

Thermometric titration – the missing piece of the puzzle

Thermometric titration – the missing piece of the puzzle

Titration is a well-established analysis technique taught to each and every chemistry student. Titration is carried out in nearly every analytical laboratory either as manual titration, photometric titration, or potentiometric titration. In this blog entry, I would like to present an additional kind of titration you may  not have heard of before – thermometric titration – which can be considered the missing piece of the titration puzzle.

Here, I plan to cover the following topics:
  1. What is thermometric titration?
  2. Why consider thermometric titration?
  3. Practical application examples

What is thermometric titration?

At first glance, thermometric titration (TET) looks like a normal titration and you won’t see much (or any) difference from a short distance. The differences compared to potentiometric titration are in the details.

TET is based on the principle of enthalpy change (ΔH). Each chemical reaction is associated with a change in enthalpy which in turn causes a temperature change. During a titration, analyte and titrant react either exothermically (increase in temperature) or endothermically (decrease in temperature).

During a thermometric titration, the titrant is added at a constant rate and the change in temperature caused by the reaction between analyte and titrant is measured. By plotting the temperature versus the added titrant volume, the endpoint can be determined by a break within the titration curve. Figure 1 shows idealized thermometric titration curves for both exothermic and endothermic situations.

Figure 1. Illustration of exothermic and endothermic titration curves showing clear endpoints where the temperature of the solution changes abruptly.

What happens during a thermometric titration?

During an exothermic titration reaction, the temperature increases with the titrant addition as long as analyte is still present. When all analyte is consumed, the temperature decreases again as the solution equilibrates with the atmospheric temperature and/or due to the dilution of the solution with titrant (Figure 1, left graph). This temperature decrease results in an exothermic endpoint.

On the contrary, for an endothermic titration reaction, the temperature decreases with the titrant addition as long as analyte is still available. When all analyte is consumed, the temperature stabilizes or increases again as the solution equilibrates with the atmospheric temperature and/or due to the dilution of the solution with titrant (Figure 1, right graph). This temperature decrease results in an endothermic endpoint.

Knowing the absolute temperature, isolating the titration vessel, or thermostating the titration vessel is thus not required for the titration.

Figure 2. Metrohm’s maintenance-free Thermoprobe used for the reliable indication of thermometric endpoints.

In order to measure the small temperature changes during the titration, a very fast responding thermistor with a high resolution is required. These sensors are capable of measuring temperature differences of less than 0.001 °C, and allow the collection of a measuring point every 0.3 seconds (Figure 2). 

Visit the Metrohm website to learn more about the fast, sensitive Thermoprobe products available even for aggressive sample solutions.

If you would like to learn more about the theory behind TET, then download our free comprehensive monograph on thermometric titration.

Why consider thermometric titration?

Potentiometric and photometric titration are already well established as instrumental titration techniques, so why should one consider thermometric titration instead?


TET has the same advantages as any instrumental titration technique:
  • Inexpensive analyses: Titration instruments are inexpensive to purchase and do not have high running and maintenance costs compared to other instruments for elemental analysis (e.g., HPLC or ICP-MS).
  • Absolute method: Titration is an absolute method, meaning it is not necessary to frequently calibrate the system.
  • Versatile use: Titration is a universal method, which can be used to determine many different analytes in various industries.
  • Easy to automate: Titration can be easily automated, increasing reproducibility and efficiency in your lab.
In comparison to classical instrumental titration, thermometric titration has several additional advantages:
  • Fast titrations: Due to the constant titrant addition, thermometric titrations are very fast. Typically, a thermometric titration takes 2–3 minutes.
  • Single sensor: Regardless of the titration reaction (e.g., acid-base, redox, precipitation, …), the same sensor (Thermoprobe) can be used for all of them.
  • Maintenance-free sensor: Additionally, the Thermoprobe is maintenance free. It requires no calibration or electrolyte filling and can simply be stored dry.
  • Less solvent: Typically, thermometric titrations use 30 mL of solvent or even less. The small amount of solvent ensures that the dilution is minimized, and the enthalpy changes can be detected reliably. As a side benefit, less waste is produced.
  • Additional titrations possible: Because enthalpy change is universal for any chemical reaction, thermometric titration is not bound to finding a suitable color indicator or indication electrode. This allows the possibility of additional titrations which cannot be covered by other kinds of titration.
  • Easier sample preparation: As TET uses higher titrant concentrations it is possible to use larger sample sizes, reducing weighing and dilution errors. Tedious sample preparation steps such as filtration can be omitted as well.
Figure 3. The Metrohm 859 Titrotherm with 801 Stirrer and notebook with tiamo™ software.

Learn more about the 859 Titrotherm system for the most reliable TET determinations on the Metrohm website.

Practical application examples

In this section I would like to present you some practical examples where TET can be applied.

Acid number and base number

The acid number (AN) and base number (BN) are two key parameters in the petroleum industry. They are determined by a nonaqueous acid-base titration using KOH or HClO4, respectively, as titrant.

During such determinations, very weak acids (for AN analysis) and bases (for BN analysis) are titrated with only small enthalpy changes. Using a catalytic indicator, these weak acids and bases can also be determined by TET.

ASTM D8045 describes the analysis of the AN by thermometric titration. The benefits of carrying out this titration are:

  • Less solvent (30 mL instead of 60 or 120 mL), meaning less waste
  • Fast titration (1–3 minutes)
  • No conditioning of the sensor

If you wish to learn more about how well the results of the AN determination according to ASTM D8045 correlate with ASTM D664, download our free White Paper WP-012 as well as our brochure below.

For more detailed information about the titration itself, download the free Application Bulletin AB-427 (AN) and Application Bulletin AB-405 (BN) below.


Using conventional titration, the salt content in foodstuff is usually determined based solely on the chloride content. However, foods usually contain additional sources of sodium, e.g. monosodium glutamate (also known as «MSG»). With TET it becomes possible to titrate the sodium directly, and thus to inexpensively determine the true sodium content in foodstuff, as stipulated in several countries.

If you wish to learn more about the sodium determination, watch our Metrohm LabCast video: «Sodium determination in food: Fast and direct thanks to thermometric titration».

Fertilizer analysis

Fertilizers consists of various nutrients, including phosphorus, nitrogen, and potassium, which are important for plant growth. TET enables the analysis of these nutrients by employing classical gravimetric reactions as the basis for the titration (e.g., precipitation of sulfate with barium). This allows for a rapid determination, without needing to wait hours for a result, as with conventional procedures based on drying and weighing the precipitate.

Nutrients which can be analyzed by TET include:
  • Phosphate
  • Potassium
  • Ammoniacal nitrogen
  • Urea nitrogen
  • Sulfate

Want to learn more about the analysis of fertilizers with thermometric titration? Download our free White Paper WP-060 on this topic. For more detailed information regarding the different fertilizer applications, check out the Metrohm Application Finder, or find a curated selection here.

Metal-organic compounds

Metal-organic compounds, such as Grignard reagents or butyl lithium compounds, are used for synthetizing active pharmaceutical ingredients (APIs) or manufacturing polymers such as polybutadiene. With TET, the analysis of these sensitive species can be performed rapidly and reliably by titrating them under inert gas with 2-butanol.

If you wish to learn more about this topic, check out our news article and download the free corresponding Application Note AN-H-142.

These were just a few examples about the possibilities of thermometric titration, to demonstrate its versatile use. For a more detailed selection, have a look at our Application Finder.

To summarize:

  • TET is an alternative titration method based on enthalpy change
  • A fast and sensitive Thermoprobe is used to determine exothermic and endothermic endpoints
  • Thermometric titration is a fast analysis technique providing results in less than 3 minutes
  • Thermometric titration can be used for various analyses, including titrations which cannot be performed otherwise (e.g., sodium determination)

I hope this overview has given you a better idea about thermometric titration – the missing piece of the titration puzzle.

For more information

Download our free Monograph:

Practical thermometric titrimetry

Post written by Lucia Meier, Technical Editor at Metrohm International Headquarters, Herisau, Switzerland.