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Guide to online and inline surface finishing analysis

Guide to online and inline surface finishing analysis

What is surface finishing?

Surface finishing is a series of industrial processes with the main goal to alter the surface of a certain workpiece in order to obtain specific properties. This can be performed chemically, mechanically, or even electronically with the aim of removing, altering, adding or reshaping the material that is being treated.

Industries that use surface finishing techniques

Surface finishing techniques are used by most industries that manufacture industrial parts (e.g., metals, wafers, tools, and more). The use of surface finishing processes has been on the rise globally and is expected to grow further. An article published by Grand View Research (2019) predicted that the market size for metal finishing chemicals is expected to grow to $13.52 billion USD by 2025.

People mostly think about polishing and sanding when surface finishing is brought up, but it is much more than that. Several industries use different processes to treat surfaces with the main objective of obtaining the highest product quality. According to Grand View Research, the top three industries with the biggest market share for metal surface chemicals are automotive and aerospace, semiconductors, and the metal industry (e.g., industrial machinery, construction).

Figure 1 shows that surface finishing is mainly used in the automotive industry. Here, electroplating and electroless plating are the main processes used to protect against corrosion. The electroplating process consists of using electricity to coat a material (e.g. copper) with a thin layer of another material (e.g. nickel). Electroless plating is accomplished with chemical processes that reduce metal cations in a bath and deposit them as an even layer, even on non-conductive surfaces.

Next is the semiconductor industry, which includes the manufacturing and cleaning surface process of electrical and electronic parts as well as silicon wafers. This industry involves plating processes (e.g., electroless plating) as well as chemical cleaning baths. Chemical cleaning baths are used here to remove any contaminants from the wafer surfaces.

Figure 1. Diagram with top five industrial applications that incorporate surface finishing techniques (graphic repurposed from Metal Finishing Chemicals Market Global Forecast to 2021). (Click image to enlarge.)
Finally comes the metal industry, responsible for creating the infrastructure that our modern world depends on. Here, the process of galvanization is used to make metal corrosion- and heat-resistant. Galvanization is an anti-corrosive measure taken with iron and steel (as well as other metals) by applying a protective zinc coating which does not allow oxidation to occur. The zinc also acts as a sacrificial anode which still protects the underlying metal in the event of a scratch in the galvanized surface. Pickling baths are another common surface finishing process for this industry. These acidic baths are used to remove the oxide layer which formed on the surface during the hot strip mill. If the base steel is over-pickled, it can result in pitting of the metal surface, leading to an undesirable rough, blistered coating in the subsequent galvanizing steps and also excessively consumes the pickling acid (e.g. HCl).

Much more than just decorative coatings

Do appearances matter? When talking about products, absolutely! One of the reasons product surfaces are treated is so they have a more pleasant appearance for consumers, but also for more technical reasons that go beyond looks. Since surface finishing processes are used in a broad range of industries, they serve different purposes depending on the uses of the final products.

In the semiconductor industry, any defect on the components (e.g., silicon wafers, microelectronics, printed circuit boards (PCB), etc.) can impact the performance of the final product. Therefore, maintaining the proper concentrations of all components in the chemical cleaning bath ensures a repeatable etching process, which for this purpose means the elimination of surface defects.

Another example includes phosphating baths, which are used to improve corrosion resistance of the product parts used in the automotive and aerospace industry. This process is performed prior to any painting to protect the body structure from environmental factors. Phosphating baths also need to be kept consistent to guarantee the correct (and identical) thickness of the protective layer in each of the products subjected to this process.

Check out our free webinar about how Process Analytical Technology (PAT) brings analytical measurements directly to the process for real-time decision-making, ensuring a high level of control for coating and finishing baths and eliminating unnecessary risk to plant personnel. Learn about real-world case studies and field-tested applications that demonstrate the advantages of optimized bath chemistry and PAT in the surface treatment industry. 

Challenges in surface finishing processes: daily bath maintenance

Like any process, surface finishing has day to day challenges which can be improved upon. Improvement can only come from knowing the bath composition and how it affects the final product. Generally, monitoring the concentration of chemical baths is done via manual sampling and titration in a laboratory on site (in some cases, by a contract lab offsite). While this method works, it can lead to long waiting times from the moment the sample is taken until the final result—therefore the results are no longer representative of the current process conditions. Because of this delay,  bath replenishment can be impaired by over- or under- dosing components, leading to suboptimal bath composition and resulting product quality (Figure 2).

Figure 2. A jagged graph such as this denotes bath quality that suffers from suboptimal conditions. A relatively flat line would suggest a stable bath composition over time, resulting in reproducible high quality surface finishing.
Manual bath analysis and chemical dosage based on old data directly influences the company’s bottom line since the manufacturer loses money either by overusing bath chemicals or producing subpar products. The larger the plating bath volume, the greater the cost of chemicals utilized. Surface finishing baths can be as large as 3500 L (1,000 gallons) or more. Thus, it is extremely important to optimize chemical dosing to reduce unnecessary costs and waste while still providing maximum quality.

If the baths are overdosed, more chemicals are used than necessary which increases overall operational costs. However, if the baths are underdosed based on old data, then the final products may be defective, which results in increased operational costs as well.

Additionally, surface finishing processes involve many hazardous substances. When carrying out any risk assessment, the first resort is the use of personal protective equipment (PPE), and any potential exposure risks should ideally be engineered out of any process.

Automated analysis of the bath components with an online or inline process analyzer completely eliminates the risk of exposure by plant personnel to the hazards associated with the chemicals used, as well as taking care of the sample preconditioning and sampling itself. With a closed loop control, quick measurements are obtained which lead to fast results and response times for optimized process adjustments.

The solution: operate more safely and efficiently with automated process analysis

Process analysis by manual titration typically takes several steps: sample collection, sample preconditioning, volumetric manipulations, calculation, logging and checking results, and finally sending feedback to the process. All of these can be totally eliminated by using online and inline analysis.

The benefits of this are very clear. By limiting the manual handling steps, any risk of exposure to hazardous chemicals is removed. Sampling error, volumetric errors, and end point ambiguity from analyst to analyst are no longer an issue. Furthermore, sampling can be carried out on a timed basis and can be programmed to occur more frequently than possible with manual methods, giving much greater process control.

The analyzer can be used to fully control a process with direct feedback of results for the correct dosage of chemicals to aging baths. Data is automatically recorded and calculated. On-screen plots and signals can warn about deviating process conditions along with alarm outputs to notify operators of bath issues. The user interface is programmed by simple intuitive operation, and can be performed even by non-chemists.

Benefits of online and inline analysis in surface finishing processes:
  • Decrease manual labor – save time and money
  • Safer working environment – avoid contact with hazardous chemicals
  • Faster response time to process changes – better product quality
  • Optimized chemical consumption – less waste, reduced costs
Learn about the differences between inline, online, atline, and offline measurements in our previous blog post.
Metrohm Process Analytics has more than 50 years of experience in process analysis and optimization. The following examples show our expertise with configuring inline and online process analyzers for different surface finishing processes.

Automated monitoring of clean and etch baths

Metal surfaces can have scratches, impurities, and other imperfections which may interfere with further manufacturing processes (e.g., plating or painting). Therefore, clean and etch baths are a key step to obtain clean, polished, and undamaged surfaces.
Figure 3. Trend chart of NH3 and H2O2 concentrations in an SC1 bath. Note the spiking of the baths to maintain their concentrations.
Traditionally, these bath chemicals are measured offline in the lab after taking a sample from the process. However, as mentioned earlier, manual laboratory methods result in long response times in case of process changes (e.g., reaction mixture, moisture levels, …), and the sample preparation can also introduce errors, altering the precision of the analysis. Additionally, it can be quite cumbersome since different operating procedures need to be implemented to analyze multiple parameters including alkalinity, ammonium hydroxide, hydrogen peroxide, and more.
Figure 4. The Metrohm Process Analytics NIRS XDS Process Analyzer is shown here with a diagram of the inline near-infrared spectroscopy (NIRS) system configuration for cleaning bath analysis.
Another example of cleaning baths are mixed acid baths, generally comprised of sulfuric acid, hydrofluoric acid, and nitric acid. Titration only provides the acid value of the sample analyzed; therefore, it is not possible to know how much of a specific acid is present in the baths. However, near infrared spectroscopy (NIRS) is the perfect analytical technique to monitor each acid individually.
Reagent-free NIRS XDS Process Analyzers enable comparison of real-time spectral data from the process to a primary method (e.g. titration) to create a simple, yet indispensable model for process optimization. NIRS is economical and fast, enabling qualitative and quantitative analyses that are noninvasive and nondestructive. Integration of inline spectroscopic techniques allows operators to gain more control over the production process and increase overall safety.

In addition to NIRS process analyzers, Metrohm Process Analytics can design and customize flow-through cells (Figure 5). These clamp on to tubing already present onsite for easy installation with no need to modify the existing setup.

Figure 5. PTFE single fiber clamp-on flow cell from Metrohm Process Analytics.

Automated monitoring of phosphatizing baths

The phosphatizing process produces a hard, electrically non-conducting surface coating that adheres tightly to the underlying metal. This layer protects against corrosion and improves the adhesion of paints and organic finishes to be subsequently applied.

Phosphatization consists of two parts: an etching reaction with phosphoric acid which increases the surface roughness, and a second reaction at the surface between the alkali phosphates and the previously generated metal ions. This coating is quite thin and offers only basic corrosion protection. The addition of metal cations (such as zinc, manganese, and calcium) to the phosphatizing bath results in the formation of very resistant zinc phosphates with a coating thickness between 7–15 times thicker, perfectly suited for outdoor use.

Figure 6. Schematic diagram of the various process stages and baths used in the phosphatizing process. (Click image to enlarge.)

In the cleaning, degreasing, and rinsing baths, and also in the phosphatizing bath itself (Figure 6), the various parameters involved in the process must be kept stable. Conductivity, pH value, free alkalinity, and total alkalinity are among the main parameters that must be determined in the degreasing and rinsing baths. Free and total acids, accelerator, zinc, and fluoride are monitored in phosphatizing baths. The 2060 Process Analyzer from Metrohm Process Analytics (Figure 7) monitors, records, and documents all of these critical parameters at the same time. The combination of different analytical methods within one system as well as the intuitive handling via the well-arranged user interface ensure easy and reliable monitoring of the entire process.

Check out our free related Process Application Note to learn more.

Figure 7. The 2060 Process Analyzer from Metrohm Process Analytics is an ideal solution for online phosphating bath applications.
To sum up, online and inline process analyzers from Metrohm Process Analytics are the ideal solution to automate the analysis of surface finishing processes because of the comprehensive benefits they provide:
  • No manual sampling needed, thus less exposure of personnel to dangerous chemicals
  • Extended bath life by tightening process windows (less chemicals required)
  • Minimize risk of downtime with faster and more precise data
  • Easier compliance with final product requirements by process automation

If you want to learn more about all the applications that we have to offer, download our free application e-book based on 45 years of global installations.

Read what our customers have to say!

We have supported customers even in the most unlikely of places⁠—from the production floor to the desert and even on active ships!
Post written by Andrea Ferreira, Technical Writer at Metrohm Applikon, Schiedam, The Netherlands.
How much do pipes rust in a year?

How much do pipes rust in a year?

Why is corrosion important?

According to the Association of Materials Protection and Performance (AMPP) the total estimated annual cost of corrosion is as high as 3.5% of a country’s GDP [1]. An AMPP international study [2] found that in the United States alone, the corrosion related cost can be as high as $1.4 billion USD annually in the oil and gas exploration and production sector. This figure climbs even higher, up to $40 billion USD for gas and drinking water distribution plus sewer systems. This is an unavoidable problem with a high cost to bear.

Even though the corrosion itself isn’t unavoidable, it can be controlled by using the right material in the right place. Using a reliable test method that evaluates the material’s resistance against corrosion and predicts its potential failure is of the utmost importance. This test method should also be cost-effective and practicable.

What is corrosion?

Corrosion refers to a naturally occurring process that involves the deterioration or degradation of metals and alloys through a chemical reaction. The corrosion rate is highly dependent on the type of material, ambient temperature, contaminants/impurities, and other environmental factors. Most corrosion phenomena are electrochemical in nature and consist of at least two reactions on the surface of the metals or alloys.

For example:

These electrochemical process require three main elements:

  • Anode: where the metal corrosion occurs.
  • Cathode: the electrical conductor, which is not consumed during the corrosion process in the real-life electrochemical cell configuration.
  • Electrolyte: the corrosive medium that enables the transfer of electrons between the anode and the cathode.

Depending on the materials and environment, corrosion can occur in different ways, such as uniform corrosion, pitting corrosion, crevice corrosion, galvanic corrosion, or microbiologically induced corrosion to name just a few. Learn more about the different types of corrosion in our free white paper.

This white paper also includes details about relevant electrochemical techniques including Linear Sweep Voltammetry (LSV), Electrochemical Impedance Spectroscopy (EIS), and Electrochemical Noise (ECN or ZRA). These techniques allow for the exploration of corrosion mechanisms, the behavior of different materials, the rate at which corrosion occurs, and also to determine the suitability of the corrosion protection solutions such as protective coatings and inhibitors, among others.

Find out more about these subjects individually with our selection of free Application Notes (AN).
Calculation of corrosion parameters with NOVA – Tafel plot corresponding to corrosion behavior of iron in seawater. (Click to enlarge)

Creating pipe-flow conditions in your corrosion laboratory

Internal corrosion is the most problematic cause of pipeline failure. To understand the fundamentals about corrosion failure and its root causes within pipelines, a similar environment should be created in the lab.

The Rotating Cylinder Electrode (RCE) is an integral part of creating hydrodynamic electrochemical experiments in the lab that create turbulent flow conditions which realistically simulate the situation for liquids flowing through pipes. The RCE can be used with most electrochemical techniques such as chronoamperometry, chronopotentiometry, and potential sweep.

Study of the corrosion rate as a function of rotation speed (convective flux) is one of the most common applications for the RCE. Corrosion studies can be performed using linear or cyclic polarization measurements (LP, DPD, CP), electrochemical impedance spectroscopy (EIS), and electrochemical noise (ECN) with respect to the rotation speed.

Results obtained by electrochemical methods are more accurate and are obtained much faster than conventional corrosion investigation methods (e.g. salt spray), providing more efficiency and productivity to any corrosion measurement laboratory. Learn about the RCE and how to simulate realistic pipe-flow conditions in the lab combined with electrochemical corrosion techniques in our free white paper.

One typical method in electrochemical corrosion studies is linear polarization (LP). With this method, it is possible to evaluate the corrosion behavior of a sample under pipe-flow (i.e. turbulent flow) conditions and learn about the corrosion rate of the sample at a specific flow rate.

Metrohm offers two Application Notes that use this technique specifically:

The Tafel plot obtained from LP measurement gives an indication of the corrosion potential. Using dedicated analysis tools in the NOVA software from Metrohm Autolab, the corrosion rate analysis can be performed and corrosion rate can be calculated, giving an indication of how much the pipe will rust in a year (in mm/year) under given conditions. Once this information is available for a certain material, a more corrosion resistive environment can be developed by applying a certain coating or a corrosion inhibitor.

Tafel plot created by Metrohm Autolab’s NOVA software. Blue line is measured without corrosion inhibitor and red line is measured with corrosion inhibitor.
Tafel plot created by Metrohm Autolab’s NOVA software corresponding to the measurements done in quiescent electrolyte (blue) and under 500 RPM rotation rate (red). All other experimental parameters were kept the same.

A second evaluation can be performed to learn how much the pipe will rust in a year, under these resistive conditions. In the example below, under standard conditions, the corrosion rate of carbon steel is measured at 0.25 mm/yr. However, when a specific corrosion inhibitor is used (tryptamine in this case), the performance is significantly improved and the corrosion rate drops to 0.065 mm/yr. These results can be achieved in a matter of minutes by using electrochemical methods, whereas by conventional methods (e.g., salt spray chamber combined with weight loss analysis), it takes up to a few months to conclude the results. That is a huge difference in efficiency!

Corrosion Parameter No Inhibitor With Inhibitor
Ecorr (V) from linear regression -0.479 -0.392
Ecorr (V) from Tafel analysis -0.482 -0.396
Rp (Ω) from linear regression 42.62 135.96
Rp (Ω) from Tafel analysis 43.32 136.39
Corrosion rate (mm/year) from Tafel analysis 0.25 0.065
Linear regression and Tafel analysis data resulting from experiments with and without corrosion inhibitor.

Summary

Understanding the corrosion behavior of a material under real-life conditions helps manufacturers to more quickly optimize the material design in terms of corrosion resistance, either by using a more suitable material for the pipes or by using adequate corrosion protection methods (i.e., coatings or corrosion inhibitors), which results in significant cost savings and safer operation.

Post written by Dr. Reza Fathi, Product Specialist at Metrohm Autolab, Utrecht, The Netherlands.

«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!

Titration

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!

Industry-focused

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.

Comprehensive water analysis: combining titration, IC, and direct measurement in one setup

Comprehensive water analysis: combining titration, IC, and direct measurement in one setup

If you perform water analyses on a regular basis, then you know that analyzing different parameters for drinking water can be quite time-consuming, expensive, and it requires significant manual labor. In this article, I’d like to show you an example of wider possibilities in automated sample analysis when it comes to combining different analytical techniques, especially for our drinking water.

Water is the source and basis of all life. It is essential for metabolism and is our most important foodstuff.

As a solvent and transporting agent it carries not only the vital minerals and nutrients, but also, increasingly, harmful pollutants, which accumulate in aquatic or terrestrial organisms.

Within the context of quality control and risk assessment, there is a need in the water laboratory for cost-effective and fast instruments and methods that can deal with the ever more complex spectrum of harmful substances, the increasing throughput of samples, and the decreasing detection limits.

Comprehensive analysis of ionic components in liquid samples such as water involves four analytical techniques:

  • Direct measurement
  • Titration
  • Ion chromatography
  • Voltammetry

Each of these techniques has its own particular strengths. However, applying them one after the other on discrete systems in the laboratory is a rather complex task that takes up significant time.

Back in 1998, Metrohm accepted the challenge of combining different analytical techniques in a single fully automated system, and the first TitrIC system was introduced.

What is TitrIC?

The TitrIC system from Metrohm combines direct measurement, titration, and ion chromatography in a fully automated system.

Direct measurements include temperature, conductivity, and pH. The acid capacity (m and p values) is determined titrimetrically. Major anions and cations are quantified by ion chromatography. Calcium and magnesium, which are used to calculate total hardness, can be determined by titration or ion chromatography.

The results are displayed in a common table, and a shared report is given out at the end of the analysis. All methods in TitrIC utilize the same liquid handling units and a common sample changer.

For more detailed information about the newest TitrIC system, which is available in two predefined packages (TitrIC flex I and TitrIC flex II), take a look at our informative brochure:

Efficient: Titrations and ion chromatography are performed simultaneously with the TitrIC flex system.

Figure 1. Flowchart of TitrIC flex II automated analysis and data acquisition.

How does TitrIC work?

Each water sample analysis is performed fully automated at the push of a button—fill up a sample beaker with the sample, place it on the sample rack, and start the measurement. The liquid handling units transfer the required sample volume (per measurement technique) for reproducible results. TitrIC carries out all the work, and analyzes up to 175 samples in a row without any manual intervention required, no matter what time the measurement series has begun. The high degree of automation reduces costs and increases both productivity and the precision of the analysis.

Figure 2. The Metrohm TitrIC flex II system with OMNIS Sample Robot S and Dis-Cover functionality.

To learn more about how to perform comprehensive water analysis with TitrIC flex II, download our free application note AN-S-387:

Would you like to know more about why automation should be preferred over manual titration? Check out our previous blog post on this topic:

Save time on your repetitive laboratory tasks with TitrIC. You don’t have to take our word for itcheck out what our customers at the Laboratory of the Swiss Canton of Zurich (Department of Elemental Analysis) have to say about TitrIC and working with Metrohm.

Calculations with TitrIC

With the TitrIC system, not only are sample analyses simplified, but the result calculations are performed automatically. This saves time and most importantly, avoids sources of human error due to erroneously noting the measurement data or performing incorrect calculations.

Selection of calculations which can be automatically performed with TitrIC: 

  • Molar concentrations of all cations
  • Molar concentrations of all anions
  • Ionic balance
  • Total water hardness (Ca & Mg)
  • … and more

Ionic balances provide clarity

The calculation of the ion balance helps to determine the accuracy of your water analysis. The calculations are based on the principle of electro-neutrality, which requires that the sum in eq/L or meq/L of the positive ions (cations) must equal the sum of negative ions (anions) in solution.

TitrIC can deliver all necessary data required to calculate the ion balance out of one sample. Both anions and cations are analyzed by IC, and the carbonate concentration (indicative of the acid capacity of water) is determined by titration.

If the value for the difference in the above equation is almost zero, then this indicates that you have accurately determined the major anions and cations in your sample.

Advantages of a combined system like TitrIC

  • Utmost accuracy: all results come from the same sample beaker

  • Completely automated, leaving analysts more time for other tasks

  • One shared sample changer saves benchtop space and costs

  • Save time with parallel titration and IC analysis

  • Flexibility: use titration, direct measurement, or IC either alone or combined with the other techniques

  • Single database for all results and calculation of the ionic balance, which is only possible with such a combined system, and gives further credibility to the sample results

Even more possibility in sample analysis

TitrIC has been developed especially for automated drinking water analysis but can be adapted to suit any number of analytical requirements in food, electroplating, or pharmaceutical industries. Your application determines the parameters that are of interest.

If the combination of direct measurement, titration, and IC does not suit your needs, perhaps a combination of voltammetry and ion chromatography in a single, fully automatic system might be more fitting. Luckily, there is the VoltIC Professional from Metrohm which fulfills these requirements.

Check out our website to learn more about this system:

As you see, the possibility of combining different analysis techniques is almost endless. Metrohm, as a leading manufacturer of instruments for chemical analysis, is aware of your analytical challenges. For this reason, we offer not only the most advanced instruments, but complete solutions for very specific analytical issues. Get the best out of your daily work in the laboratory!

Read our article

in LC/GC’s The Column November 2020 edition:

Environmental Analysis with Integrated Ion Chromatography, Titration, and Direct Measurement

Post written by Jennifer Lüber, Jr. Product Specialist Titration/TitrIC at Metrohm International Headquarters, Herisau, Switzerland.