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Discover our blog on the Metrohm website

Discover our blog on the Metrohm website

by | Mar 28, 2022 | Company

Metrohm Discover: A new platform

From now on, new «Analyze This» posts will only be featured on the Metrohm website rather than WordPress.

We invite you to come check out our articles on the Metrohm Discover platform, where you will find all kinds of helpful material organized by industry, matrix, analyte, and measuring technology. Find everything you need easily with our new platform.

Check out the blog on Metrohm Discover

Thank you!

Thanks to all of our loyal readers who have made this analytical chemistry blog such a success. Keep reading our articles, and visit your local Metrohm website for other articles in your native language!

Discover the world of chemistry

Find the newest blog articles and more on our website

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Post written by Dr. Alyson Lanciki, Scientific Editor at Metrohm International Headquarters, Herisau, Switzerland.
Ph. Eur. 2.2.48 Raman Spectroscopy: How Raman instruments from Metrohm comply with the 2022 update

Ph. Eur. 2.2.48 Raman Spectroscopy: How Raman instruments from Metrohm comply with the 2022 update

by | Nov 29, 2021 | Analysis, Company

The European Pharmacopoeia (Ph. Eur.) is a single reference work for the quality control of medicines. Ph. Eur. contains norms, suggests analytical methods, and lists many properties that define quality control (QC) during the production of medicines, the raw materials used, and the instruments required to perform such tests. These official standards are legally binding in several countries – not only in Europe, but worldwide.

Raman spectrometers—especially handheld and portable instruments—are increasingly used for QC of medicines and raw materials (RMID). Instrument interfaces are user-friendly, requiring little technical expertise, and they provide flexible sampling options for most sample types with rapid, non-destructive measurements.

Metrohm’s Raman systems exhibit great flexibility—from see-through to standoff to immersion sampling.
An excerpt from the Ph. Eur. 2.2.48 Raman Spectroscopy chapter says:
«Raman spectroscopy is commonly used for qualitative and quantitative applications and can be applied to solid, liquid, and gaseous samples. Raman spectroscopy is a rapid and non-invasive analytical method and can be performed off-line, at-line, on-line, or in-line[…] Raman spectrometers can be situated far from the point of measurement using long-distance optical fibres to collect the Raman signal.»

For a look at RMID from start to finish, download our free four-part tutorial series.
Handheld Raman for RMID in pharma and other regulated industries
Technological developments and their increasing adoption in the pharmaceutical industry prompted a revision of Ph. Eur. 2.2.48 which ensures the reliability of Raman results. The updated chapter 2.2.48 was published in the Ph. Eur. Supplement 10.7 (October 2021) and will ultimately take effect in April 2022.

While much of the Ph. Eur. 2.2.48 chapter has remained the same, the latest revision features:

  • new requirements for spectral resolution for qualitative Raman analysis using a suitable reference material
  • updated requirements for the Raman response-intensity scale
  • detailed procedures for the comparison of spectra

We will address these new requirements across our Raman spectroscopy product lines in the rest of this article.

Spectral Resolution

«Spectral resolution is the ability of a spectroscopic system to separate adjacent bands, which makes it possible to characterise complex samples (e.g., brand analysis, crystallinity, polymorphism).

[…] For identity tests, unless otherwise prescribed in a monograph, the spectral resolution must be less than or equal to 15cm-1 (measured in the wavenumber range between 1000cm-1 and 1100cm-1).

The spectral resolution is verified using a suitable reference material. The instrument parameters used for the test, such as laser, slit-width and grating for dispersive instruments and circular aperture […] for FT-instruments, must be the same as those applied for sample measurements. For example record the Raman spectrum of calcium carbonate for equipment qualification CRS, and determine the full width at half height (W1085) of the band located at 1085 cm-1. The spectral resolution (R) using calcium carbonate is then given by the following relation:»

Handheld Raman instruments: MIRA P and NanoRam

All MIRA P and NanoRam devices (including both NanoRam and NanoRam-1064) for the pharmaceutical industry are designed and tested to meet stringent resolution requirements. During QC, the resolution of each instrument is tested to be less than 15 cm-1 against a secondary USP (US Pharmacopeia) reference standard of calcium carbonate according to ASTM E2529, which is the same procedure recommended in this newly released Ph. Eur. chapter.

The measured spectral resolution value for each instrument, along with its identifying serial number, is included in the instrument final test report. A certificate or final test report is packaged with the device and sent to the customer (starting in April 2022 for MIRA P). This resolution is fixed by the optical design of the instrument and is stable over time.

Portable Raman instruments: i-Raman series, QTRam, STRam, and PTRam

The instrument resolution for all of Metrohm’s portable Raman instruments from B&W Tek are factory-tested with calcium carbonate and displayed on final instrument test reports. The spectral resolution is dependent on the instrument design and defined for each specific instrument configuration. Depending on the instrument model, the spectral resolution is between 3.5–11 cm-1. Additionally, the instrument control softwares Vision and BWAnalyst have the performance test function that verifies spectral resolution using the 1001.4 cm-1 peak of polystyrene.

Handheld and portable Raman instruments from B&W Tek.

Response-Intensity Scale

«The verification of the response-intensity scale is principally performed for quantitative methods.

Appropriate acceptance criteria will vary with the application. A maximum variation of ± 10 per cent in band intensities compared to the previous instrument qualification is achievable in most cases. Response calibration may involve the use of white-light standards or luminescent glass (e.g., NIST SRM 2241).»

Handheld Raman instruments: MIRA P, MIRA M-3, and NanoRam series

MIRA P, MIRA M-3, and NanoRam systems are designed for qualitative analysis, not for quantitative purposes. Therefore, this criterion is not a strict requirement for handheld Raman products.

However, the relative intensity response of MIRA P and NanoRam series instruments is calibrated with a NIST standard SRM calibration material (SRM 2241, SRM 2242) or NIST SRM 2241-traceable calibration standard to achieve better uniformity from instrument-to-instrument.

The NanoRam series instruments have an acceptance criterion for relative intensity response in the instrument performance validation in alignment with Ph. Eur. 2.2.48 and USP<858>. To pass the performance validation, <10% relative intensity error is required using the factory-supplied polystyrene cap.

Portable Raman instruments: i-Raman series, QTRam, STRam, and PTRam

The relative intensity response of these portable Raman instruments is calibrated using a proper NIST standard SRM calibration material to achieve better uniformity from instrument-to-instrument. Additionally, the Vision instrument control software includes the performance test function that verifies the intensities of several Raman peaks of polystyrene relative to its 1001.4 cm-1 peak, to a maximum variation of ±10% compared to the previous instrument qualification.

Comparison Procedures

For qualitative methods, additional information for identification has been defined.

«Several comparison procedures may be used, and the analyst must document and justify the method used and the specific acceptance criteria that allow a conclusion for identification. The spectra can be compared by either overlaying the spectra (in the whole spectral range or in the region of interest specified in the monograph) or by using mathematical calculations of the software. It is possible for example to perform:

  • visual comparison based on band positions and relative intensities unless otherwise specified[…]
  • a statistical determination of the similarity between the spectra of the material to be examined and the reference standard[…]
  • evaluation by chemometric methods[…]»

While an experienced Raman spectroscopist can certainly compare spectra visually and assess sample validity based on peak location, fluorescence, saturation, and signal-to-noise ratio, the widespread implementation of Raman in the real world means that complex analysis must be done by the device and not the user. Statistical comparison methods are used primarily for identification of unknowns through correlation of a sample spectrum with library spectra. The software performs library searches and returns a Hit Quality Index (HQI) value indicating the level of correlation as defined by a user-defined threshold.

Chemometric methods rely on dimensionality-reduction methods that are performed by the software, such as Principal Component Analysis (PCA), where new sample data is compared within a multivariate model created from representative samples. This permits highly accurate verification of known materials according to how well a spectrum fits into the model limits, which are determined by a confidence interval. In the analysis of medicines and raw materials, chemometric methods are used to distinguish the quality and consistency of a material. MIRA P (and its dedicated software, MIRA Cal P) and NanoRam instruments use both statistical and chemometric methods for sample identification and verification based on the needs of the end-user.

For more information, download our free technical and application notes as well as a White Paper below.

Pros and Cons of Using Correlation vs. Multivariate Algorithms for Material Identification via Handheld Spectroscopy
Method Development with NanoRam®-1064
Simplified RMID Model Building – Mira Cal P and Model Expert
White Paper: Verification, p-values, and Training Sets for the Mira P

Wavenumber accuracy requirements of Ph. Eur. 2.2.48

«Verify the wavenumber scale for Raman shifts using a suitable standard that has characteristic maxima at the wavenumbers under investigation, for example an organic substance such as polystyrene, paracetamol or cyclohexane[..]

A minimum of 3 wavenumbers covering the working range of the instrument intended for measurements should be selected.[…]»

This chapter maintains the same requirements for Raman wavenumber accuracy and is consistent with the USP <858> and JP 2.26. All of Metrohm’s handheld Raman instruments meet these requirements. Users are recommended to run performance validation tests at regular intervals using polystyrene or another ASTM Raman shift calibration material.

Download our free White Paper below to learn more about instrument calibration, system verification, and performance validation.

Instrument Calibration, System Verification, and Performance Validation for Metrohm Instant Raman Analyzers (Mira)
The Calibrate/Verify Attachment (CVA) shown here is a dual-ended accessory containing a toluene/acetonitrile ASTM standard for calibration/verification of the wavenumber axis and polystyrene for a second wavenumber verification according to Ph. Eur. 2.2.48.
Performance tests for Raman wavenumber accuracy are included the Vision and BWAnalyst softwares for the i-Raman series and other portable Raman products (STRam, QTRam, PTRam), with acceptance criteria in accordance with the pharmacopeial requirements.

Metrohm’s unique way of compliance with Ph. Eur. 2.2.48

Better representation of the material

«When using Raman spectroscopy[…] care must be taken to ensure that the measurement is representative. This can be achieved by, for example rotation of the sample, performing multiple measurements on different preparations of the sample, using orbital raster scanning (ORS), increasing the area of illumination by reducing the magnification, by demagnification of the laser beam or by changing the focal length between measurements to scan at different depths.»

ORS™ is Metrohm Raman’s proprietary method for moving the excitation laser in a pattern over a sample in order to collect more representative data from a larger area of the sample, especially on heterogeneous samples. All MIRA and MISA instruments are equipped with ORS.
Learn more about ORS by downloading the related Application Note.
Improving verification with Orbital Raster Scan technology
For more details about how we comply, please check the U.S. Pharmacopeia Raman Chapters Updates page on the B&W Tek website. For more general information, download this General Compliance Statement for MIRA handheld Raman systems
B&W Tek: U.S. Pharmacopeia Raman Chapters Updates
MIRA General Compliance Statement
For a more comprehensive look at raw material identification and verification in the pharmaceutical industry, there is a significant amount of information on this topic in our related blog post.
Real World Raman: Simplifying Incoming Raw Material Inspection

Post written by Dr. Melissa Gelwicks (Technical Writer at Metrohm Raman, Laramie, Wyoming), and Dr. Xiangyu (Max) Ma (Handheld Raman Product Manager) and Dr. Jun Zhao (R&D Director) at B&W Tek, Plainsboro, New Jersey.

The evolution of handheld 785 nm Raman spectroscopy: Raman extraction from fluorescence interference

The evolution of handheld 785 nm Raman spectroscopy: Raman extraction from fluorescence interference

by | Nov 1, 2021 | Analysis, Company, Fundamentals

MIRA DS (Metrohm Instant Raman Analyzer) is a handheld Raman system that identifies materials using 785 nm laser excitation. The advantages of using 785 nm Raman are well understood. Excitation with shorter wavelengths produces strong Raman scattering with short acquisition times. This results in a high signal-to-noise ratio and provides excellent spectral resolution with lower power draw. These are just some of the reasons that handheld Raman has become so popular over the last two decades.

The sensitivity of Raman at 785 nm also means that lower laser powers can be used. Lower laser powers help to protect sensitive samples from burning or ignition. The silicon detectors used at shorter wavelengths do not need to be cooled, further extending battery lifetimes. The net result is that 785 nm systems can be very small and still provide fast and accurate material identification for long hours in the field.

Learn more about how MIRA became mobile in our previous blog post.
«Analyze This»: How Mira Became Mobile
However, while this is considered the «sweet spot» for both a strong signal and fluorescence mitigation among possible wavelengths, approximately 10% of Raman active materials fluoresce under interrogation with 785 nm Raman systems [1]. For example, Gum Arabic is a widely used filler and binding agent. When sampled with 785 nm systems, its fluorescence overwhelms the Raman signal (more on this subject later). Similarly, cutting agents (e.g., sucrose found in street drugs) fluoresce and can prevent positive identification of the target substance. Dyes can be problematic in the analysis of tablets, foodstuffs, art, and plastics as well. Often, weak Raman features can still be observed in fluorescent materials with 785 nm interrogation, but fluorescence mitigation is crucial for library matching.

Previous recommendations to overcome fluorescence

When fluorescence is an issue, 1064 nm laser excitation is often recommended. The tradeoffs include higher laser power, increased sample heating, longer interrogation times, and low Raman scattering efficiency. Often, this means larger instruments with shorter battery lifetimes. Instruments from some manufacturers require longer acquisition times that slow down sampling and can potentially damage the sample.

Is there a better way?

In a word, yes. SSE (Sequentially Shifted Excitation) can be used to remove fluorescent contributions to a Raman spectrum by using a laser that shifts the excitation wavelength as a function of the laser temperature. The result is a very large «handheld» system with a shoulder strap and a high price tag, partly due to the expensive laser used. Aside from the bulk and the cost, another issue with these systems is that the constant temperature cycling of the laser causes the system’s battery to have a short lifetime.

A Metrohm solution

Metrohm Raman has designed a fluorescence rejection system based on its compact MIRA DS package using an IPS single-mode 785 nm laser. The system is capable of producing excellent spectral resolution and flat baseline data with low laser power, short acquisition times, and all of the other excellent functionalities that users have come to expect from MIRA DS.

This fluorescence rejection system is built upon a MIRA DS platform, preserving all of its unique capabilities:

Safety in Any Situation – Addressing the needs of first responders
Improving verification with Orbital Raster Scan (ORS) technology
Mira DS and KnowItAll Raman Spectral Library (Handheld) from Wiley
Smart Acquire – Automated Raman Material ID for Defense and Security Professionals
On-site Identification of Improvised Incendiary Devices: Integrated Chemical ID and Decision Guidance with MIRA DS and HazMasterG3®
Determination of Heroin in Street Drug Samples

MIRA XTR DS

MIRA XTR DS is the evolution of Raman spectroscopy. It combines the smaller size, higher resolution, and lower power consumption of a 785 nm Raman instrument with patent-pending advanced algorithms to eXTRact Raman data, even from spectra that have strong fluorescence!
Figure 1. Comparison of Raman spectra of Gum Arabic powder measured by 1064 nm, 785 nm (MIRA DS), and XTR® (MIRA XTR DS).
Figure 1 contains Raman spectra from a fluorescent material, Gum Arabic powder, with traditional 785 nm and 1064 nm laser excitation, in addition to MIRA XTR DS. The improvement in resolution with XTR is obvious. Notice the very flat (uncorrected) baseline in the XTR spectrum on the bottom. This is crucial for library matching with a Pearson correlation, where the dot product between spectra and non-zero baselines contribute strongly to the correlation.

Learn more about MIRA XTR DS on our website.

MIRA XTR DS: The evolution of handheld Raman for fluorescence-free material identification
Applications for MIRA XTR DS include Sensitive Site Exploitation / Intelligence Surveillance Reconnaissance (SSE/ISR) of clandestine labs and determination of synthetic routes to illicit products. MIRA XTR DS is designed for real world scenarios like the analysis of methamphetamine lab residues and identification of narcotics in street drug samples. This includes ID of narcotics, despite cutting agents that fluoresce and fail analysis at 785 nm. ORS™ combined with fluorescence rejection means that MIRA XTR DS can also delicately interrogate sensitive materials like colored explosive compounds.

Download our free White Paper below to find out more about the capabilities of MIRA XTR DS.

White Paper: Fluorescence-free 785 nm material identification with MIRA XTR DS

Classic applications improved with MIRA XTR DS

Lidocaine [2] is a local anesthetic that can also be used to cut cocaine because it enhances the immediate numbing sensation that many cocaine users associate with a high quality product. Since cocaine is typically present at only ~30% in street samples, its signal can be occluded by other components in the mixture. However, positive identification of common cutting agents like lidocaine can lead to further investigation of a suspect sample.

Traditionally, lidocaine was an issue for 785 nm Raman systems, as its fluorescence prevented both positive identification of lidocaine and detection of cocaine. MIRA XTR DS produces an excellent, fluorescence-free, resolved spectrum of lidocaine (Figure 2).

Figure 2. Comparison of Raman spectra of lidocaine hydrochloride measured by 1064 nm, 785 nm (MIRA DS), and XTR (MIRA XTR DS).
Diphenhydramine is another example of a common OTC drug that, when detected, may suggest darker dealings. It can be abused on its own, but it is also a potential precursor in the synthesis of methamphetamine. Diphenhydramine exhibits some fluorescence when interrogated with 785 nm Raman (Figure 3), but it is also typically present in mixtures with inert ingredients that fluoresce. For this type of analysis, SERS can be used to detect trace amounts of a substance. This is an excellent showcase for MIRA XTR DS, because it can perform both 785 nm Raman and SERS tests, while most 1064 nm systems currently on the market cannot be used for SERS analysis.
Figure 3. Left: MIRA XTR DS used for no-contact testing. Right: Comparison of Raman spectra of Diphenhydramine measured by 1064 nm SERS, 785 nm SERS (MIRA DS), and XTR SERS (MIRA XTR DS).
What’s the difference between Raman and SERS? Read our blog article to find out!
«Analyze This»: Raman vs SERS… What’s the Difference?

But MIRA XTR DS can do more!

With fluorescence mitigation, 785 nm Raman can be used more generally for material identification and chemical analyses.

Microcrystalline Cellulose

Microcrystalline cellulose (MCC) is another inert excipient that is commonly used in food production and the pharmaceutical industry. When interrogated with 785 nm Raman, its fluorescence can overwhelm the Raman signal and prevent identification and mixture matching (Figure 4).

Figure 4. Comparison of Raman spectra of MCC measured by 1064 nm, 785 nm (MIRA DS), and XTR (MIRA XTR DS).
Ketchup

Measurement of analytes in ketchup is a particularly interesting application, as it is a highly colored, complex mixture. With 785 nm testing, it shows fluorescence—with 1064 nm testing, it burns. But XTR analysis carries the added benefit of signal enhancement, returning a spectrum that clearly indicates the presence of trace lycopene in ketchup—the chemical that contributes its red color (Figure 5).

Figure 5. Comparison of Raman spectra of ketchup measured by 1064 nm, 785 nm (MIRA DS), and XTR (MIRA XTR DS).
Another important application demonstrates how MIRA XTR DS can distinguish imitation honey from the pure, unadulterated form in the pursuit of fraudulent food products, and that it shows promise for quantitative analysis. MIRA XTR DS extracts Raman spectra from materials that typically show fluorescence with 785 nm excitation, this time with sufficient resolution to detect different ratios of mixtures (Figure 6).
Figure 6. Comparison of Raman spectra of pure honey (left) and imitation honey (center) measured by 1064 nm, 785 nm (MIRA DS), and XTR (MIRA XTR DS). Right: Determination of the ratio of different mixtures of pure honey with adulterants using MIRA XTR DS. (Click image to enlarge.)

A powerful laboratory in the palm of your hand

Historically, Raman users dealt with fluorescence by using instruments with a 1064 nm laser. MIRA XTR DS combines the smaller size, higher resolution, and lower power consumption of a 785 nm laser with revolutionary machine learning to eXTRact Raman from fluorescent samples. The benefits are considerable!
  • Low power 785 nm laser interrogates sensitive samples without risk of ignition or burning.
  • Compact, pocket-sized design enables true single-handed operation of the device
  • The low power consumption means longer battery life for extended field use

MIRA XTR DS: all the best of handheld Raman with virtually unlimited applications.

Find out more about MIRA XTR DS

Download free white papers and learn more on our website.

Click here!
References

[1] Christesen, S. D.; Guicheteau, J. A.; Curtiss, J. M.; Fountain, A. W. Handheld Dual-Wavelength Raman Instrument for the Detection of Chemical Agents and Explosives. Opt. Eng. 2016, 55 (7), 074103. DOI:10.1117/1.OE.55.7.074103

[2] Barat, S. A.; Abdel-Rahman, M. S. Cocaine and Lidocaine in Combination Are Synergistic Convulsants. Brain Res. 1996, 742 (1), 157–162. DOI:10.1016/S0006-8993(96)01004-9

Post written by Dr. Melissa Gelwicks, Technical Writer at Metrohm Raman, Laramie, Wyoming (USA).
Developing the electrochemical sensors of your dreams

Developing the electrochemical sensors of your dreams

by | Apr 26, 2021 | Company

«Measurement is the first step that leads to control and ultimately to improvement. If you can’t measure something, you can’t understand it. If you can’t understand it, you can’t control it. If you can’t control it, you can’t improve it.»
– H. James Harrington

 

The statement above relates very well to the demand to measure more and more about our lives—one option available to achieve this improvement is through the development of electrochemical sensors. Sensor manufacturing is in high demand and is expected to grow exponentially in the coming years.

Everything around us gives valuable information, including the chance to discover and the ability to know how we need to act. Developing sensors opens up new opportunities to develop and customize powerful and accurate solutions for specific applications in multiple fields, as well as being able to monitor different parameters outside the laboratory on the spot.

Electrochemical sensors and biosensors that are developed in small sensor strips allow for many measurement and monitoring possibilities. Sensors with new strategies have evolved by working with new materials, substrates, and formats that improve their accuracy, miniaturization, and portability in response to new analytical paradigms in various markets.

Why are electrochemical sensors needed?

Electrochemical sensors are a sensitive, fast, accurate, and cost-effective solution for point-of-care measurements. Such characteristics make these solutions suitable for integration into various monitoring or automation systems which, combined with a data communication structure, can generate considerable advances in the field of biosensing, creating new and important possibilities for the market as practical and future-proof solutions.

The latest advances in the miniaturization of electrochemical sensors is another reason for their growing use and popularity. These portable and simple formats are geared towards the end user—technical and non-technical—to obtain results in their daily work. This makes electrochemistry very attractive to anyone thinking of taking an idea or research to the next level and commercializing their findings.

This progress makes the development of electrochemical sensors one of the most active areas of analytical electrochemistry. These sensors are capable of providing information with superior features such as: real-time data generation, disposability, high accuracy, or wide-range linearity that make these small sensor strips an advanced alternative to conventional, bulky and expensive analytical instruments.

Multiple possibilities for production of electrochemical sensors

Your dream sensor is now possible thanks to expert manufacturing from Metrohm DropSens that allows customization and production according to your required quantity and specifications. Using an innovative and experienced production process, large quantities of customized sensors can be produced while maintaining high product quality and scalability stability as well as an attractive price-performance ratio.

Optimized design

Metrohm DropSens R&D experts understand the application concept in depth. The engineering and design departments assist in the development process to implement a final prototype, always finding a solution in which all specifications converge.

 

Custom-made solutions

The development of these sensors allows their miniaturization while at the same time allowing the possibility of modifications in terms of spatial distribution, shape, area, substrate, or the use of a wide range of materials, to name just a few. In addition, flexible sensors, textile sensors, biosensors or other types of solutions can be manufactured to suit the biochemical and electronic process needs of each individual application.

 

 Manufacture on demand

Take advantage of this capacity to produce custom-made electrochemical sensors on demand efficiently and quickly, regardless of the quantity ordered, meeting future needs without ever running out of supply.

 

High performance market-ready solutions

Be the first to bring a sensor to market, avoiding long processes and an abundance of partners. Count on the fast and professional manufacturing capability from a company positioned directly in the launch and production of electrochemical sensors to the market.

 

The highest quality standards

Production is carried out with the highest quality materials, printing, and finishing. In addition, the solutions are approved by quality management systems, which allows the highest levels of reliability and stability to be achieved in each product, guaranteeing its scalability.

From small-scale prototyping to large-scale sensor production, Metrohm DropSens offers support throughout the entire process: initial conceptualization, in-depth prototype design, and helping to achieve results that meet your goals.

This expert manufacturing is backed by the global support of Metrohm’s extensive worldwide network of partners. With more than 75 years of experience, Metrohm offers the highest standards of product and service quality, providing all you need for chemical analysis support.

Sensors for infinite uses

Progress and improvement cannot be adequately defined without the use of sensors. Everything can be measured (and usually quantified), which gives many opportunities to grow. State-of-the-art sensors based on the most recent scientific accomplishments excel in their customer-friendliness, allowing sensors to become part of everyday life as they are accessible to more people. Furthermore, the development of these decentralized devices can leverage R&D in many different industry sectors by addressing their specific applications and needs, giving them the option to reach the market.

The measurement of human health, pollution, information about foods and beverages, environmental analysis, water contamination, illicit drugs, or viruses, among other things, can be performed with electrochemical techniques and solutions. Sensors also play a fundamental role in industrial sectors such as agriculture and livestock farming, being able to measure an infinite number of parameters applicable to their improvement and development.

Another aspect to be taken into account regarding the development and growth of relevant sectors is the capacity of sensors for continuous electrochemical monitoring of different biomarkers. Combined with automated wireless data communication systems, this has represented a considerable advance in the field of biosensing towards new market possibilities.

Certified by ISO 13485 for the manufacture of sensors for medical devices

In the clinical setting, point-of-care (POC) testing dominates as an end-user application. The main areas of development focus especially on POCs for home monitoring of chronic diseases and POC testing of infectious pathologies, among others.

The COVID-19 pandemic, caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a threat to global public health. Therefore, the development of a rapid, accurate, and easy-to-apply diagnostic system for the detection of the virus has become crucial to control the outbreak of infection and monitor the progression of the disease. 

Metrohm DropSens manufactures electrochemical sensors under ISO 13485 certification, which attests to the ability to provide production that consistently meets customer and regulatory requirements applicable to medical devices and related services.

Read more here about the use of screen-printed electrodes for virology research in our blog post!

«Analyze This»: Virus detection using screen-printed electrodes

The sectors of medical and diagnostic services are driven by a strong interest in rapid point-of-care testing and monitoring devices. In addition, the integration of biosensors into medical diagnostic equipment will offer endless opportunities for the market for prevention and control of the spread of disease.

Moreover, the proliferation of biosensors employing electrochemical sensing technology has been gaining ground due to the strong demand for rapid and non-invasive POC applications. These are market-ready sensors that can be used by anyone.

Electrochemical test strips are a suitable canvas and format for the creation of a motorized diagnostic and testing system in this area and can provide a solution to these new analytical paradigms. The development of non-invasive sensors for decentralized and continuous monitoring has received a great deal of attention from researchers in different industries for painless analysis of important health parameters.

These are extraordinary times for sensor development

We constantly look for ways to mark our progress, and having the ability to measure parameters is one way to achieve this. The development of electrochemical sensors opens up a wealth of possibilities, and thanks to the customization and mass production capabilities of Metrohm DropSens, you will be able to produce high quality electrochemical devices that are tailored to specific applications. This production process is designed to meet the long-standing market demand for end-user-oriented sensor solutions with features such as: portability, wireless functionality, and simple usability without any loss in measurement accuracy.

Electrochemical sensors, based on small sensor strips, are now simpler, smarter, more user-oriented, and cheaper than conventional electrodes, which rely on cleaning or recovery tasks and have lower reproducibility in many areas of analysis. These devices are also characterized by the ability to acquire data in real time, which, combined with portability and ubiquitous availability, makes them practical and powerful tools for measurement purposes. In addition, they can provide an alternative solution for applications where complexity is involved, as they can be developed to adapt to infinite specifications.

Electrochemical sensors guarantee optimum quality, excellent measuring accuracy, and use perfectly bonded materials, prints, and substrates. They can be developed in various formats and are reproducible on flexible or even wearable materials, always maintaining good conductivity and preserving the correct alignment of the different sensor elements in all cases.

Metrohm DropSens is able to produce these electrochemical sensors in large quantities on a customized basis while still maintaining all the benefits and features scaled up from the customer-developed application. This is possible while guaranteeing market-ready production, an efficient price-performance ratio, and no risk of stock-outs – always with continuous global and specialized support service. Contact us to make your dream sensor a reality!

Dream of your sensor

and together we will make it true

Click here to find out more

Post written by Belén Castedo González, Marketing Communication at Metrohm DropSens, Oviedo (Asturias), Spain.

Decarbonizing chemical processes with Thor

Decarbonizing chemical processes with Thor

by | Apr 22, 2021 | Company

The chemical manufacturing industry consumes approximately 10% of the energy produced worldwide and is responsible for more than 5% of global carbon emissions. Nearly all chemicals are synthesized using thermal energy generated by fossil fuel combustion, leading to the significant carbon footprint from this sector. What if there was a way to reduce the carbon footprint without requiring significant amounts of energy or high costs? That is where the 2021 Metrohm Young Chemist Award winner, Ryan Jansonius, comes in.

Ryan Jansonius is a Ph.D. candidate at the University of British Columbia and a co-founder of ThorTech. He received his BSc (Hons) in Chemistry from the University of Calgary in 2016. He then went on to work at the Automotive Fuel Cell Cooperation, a subsidiary of Ford and Daimler, developing ion exchange membranes for hydrogen fuel cell vehicles. His research in the Berlinguette group at UBC has centered around developing technologies that use inexpensive and abundant renewable electricity to drive otherwise environmentally costly chemical transformations. ThorTech is bringing to market a unique membrane reactor technology that uses water and electricity to hydrogenate molecules relevant to the biofuel, pharmaceutical, and specialty chemical industries.

The Metrohm Young Chemist Award

Metrohm values the spirit of innovation and believes in the value of novel research performed by pioneering young scientists. At Metrohm USA, the tradition of holding a yearly contest for early career researchers has gone on for nearly a decade! Every year, between 50 and 75 entries are received to try and win a grand prize of $10,000 USD.

A panel of judges from inside and outside of the company reviews the submissions and scores the applicants’ responses to the questions on the application. Finalists are then asked a series of follow up questions from the judges and asked to summarize their role in the work and its future potential. A winner is chosen, who then presents their research at PITTCON. Watch Ryan’s presentation at PITTCON 2021 below!

Past winners of the MYCA  have gone on to continue their research and broaden their horizons using the prize money to do things they otherwise would have had to pass on.

Learn more about the Metrohm Young Chemist Award here! Applicants do not have to use Metrohm instrumentation to be considered, and it plays no part in winner selection.

Metrohm Young Chemist Award

Decarbonizing the chemical industry

Ryan’s doctoral research at UBC focuses on finding ways to decarbonize chemical manufacturing. The production of fuels, plastics, fertilizers, pharmaceuticals, and specialty chemicals consumes a significant amount of energy and is responsible for 5% of all greenhouse gas emissions. By developing ways to produce these useful chemicals using only abundant feedstocks and renewable electricity, there is an opportunity to offset these emissions.

To decarbonize chemical processes, Ryan and his group are developing a reactor that can use renewable electricity to drive chemical reactions that would otherwise require fossil fuel inputs. The type of reaction they are targeting is called «hydrogenation», and it is used in about 25% of all chemical manufacturing across several industries. Hydrogenation is a simple chemical process where hydrogen atoms are added to an unsaturated chemical feedstock.

Normally, this requires high pressure, high temperature hydrogen gas to achieve, which is extremely dangerous to handle. Conventional technology requires capital intensive hydrogenation plants for this purpose and has not changed for nearly a century.

The reactor, called «Thor», produces hydrogen through the electrolysis of water, which then passes through a thin membrane and hydrogenates an organic feedstock. What makes Thor unique is the use of a palladium membrane as a cathode, hydrogen-selective membrane, and hydrogenation catalyst simultaneously. This architecture enables the electrolysis to proceed in aqueous electrolyte while hydrogenation is mediated in organic solvent. Both reactions proceed efficiently as a result.

Team Thor (left to right): Ryan Jansonius, Natalie LeSage, Roxanna Delima, Mia Stankovic. Not pictured: Arthur Fink, Camden Hunt, Aoxue Huang, and Aiko Kurimoto. The technological innovation is defined by the large number of female group members, as shown by their lead authorship on several peer-reviewed articles (listed at the bottom of the page).

This process circumvents the use of fossil-derived H2, and the natural gas heaters required for conventional thermochemical hydrogenation reactors used industrially today. The ultimate goal is to use Thor to produce renewable diesel, pharmaceuticals, and a host of bio-derived specialty chemicals in a way that is cleaner, safer, and more cost-effective than conventional methods.

The legend of Thor(Tech)

Where did the name «Thor» originate?

Studying the palladium-hydrogen system led the Berlinguette research group to develop the Thor reactor in 2018. The inventor of the technology, Rebecca Sherbo (currently a postdoctoral fellow at Harvard), came up with this idea after studying the bizarre hydrogen absorption properties of palladium. The first setup and proof of concept was a tandem hydrogenation oxidation reactor. Now, instead of the paired electrolysis method they use water hydrolysis as a hydrogen source, but kept the great name to remind them of the history.

What is ThorTech? Ryan and his research team explain their project in a nutshell:

Earlier iterations of the prototype reactor developed by Ryan’s research group at UBC.

Potential commercial impact of greener technology

Thor solves key challenges with conventional hydrogenation methods by using water as a hydrogen source. Therefore, pressurized H2 gas is no longer required, which is challenging to handle and store. The reactivity of hydrogen atoms delivered to the organic feedstock in the reactor is on the order of hundreds of atmospheres. Hydrogen sourced from water can therefore be used to hydrogenate organic molecules without the use of dangerous reagents or high temperatures. Using electricity as the only energy input also enables the device to be carbon neutral if is coupled to a renewable electricity source.

A close-up view of the Thor benchtop reactor.
An expanded view of the internal parts in the flow cell.

Why choose Metrohm?

So, why choose Metrohm over other providers? I asked Ryan about his experiences with our line of potentiostats for his doctoral research in the Berlinguette lab group at UBC.

«All of the potentiostats that we use are Metrohm potentiostats in the lab. The only piece of fancy equipment or scientific equipment we need to run it [Thor] is a potentiostat. We have one big multichannel potentiostat with five or six individual channels in it, and we run all of our reactions off of that.»

Ryan Jansonius

MYCA 2021 Winner and Ph.D. Candidate, University of British Columbia

Learn more about Metrohm’s electrochemical instruments on our website!

Electrochemistry by Metrohm
A Metrohm Autolab Multichannel instrument. Each channel is a separate potentiostat/galvanostat module, allowing you to perform up to twelve measurements on just as many individual electrochemical cells.

«The thing that sets them apart from other potentiostats I’ve used is that the user interface is really good. The Metrohm software has a lot of default procedures and makes making custom procedures almost brainless, which is great.

You want to use your brain for the hard stuff, not the “set up the instrument” stuff.»

Ryan Jansonius

MYCA 2021 Winner and Ph.D. Candidate, University of British Columbia

We wholeheartedly agree! For more information about potentiostats from Metrohm Autolab, visit the website.

Metrohm Autolab

The next steps

The Thor team is currently working to develop membranes that use less palladium, designing flow cells to increase reaction rates and efficiency, and screening catalysts that enable a broader scope of feedstocks to be hydrogenated in Thor.

Dr. Aiko Kurimoto, a postdoctoral fellow on the Thor team has shown that depositing thin layers of different catalysts on the palladium cathode leads to substantially higher reactivities. This work was published in Angewandte Chemie (2021).

Of course, the COVID-19 pandemic has influenced research activities across the globe, and it is no different for our Metrohm Young Chemist Award winner. After spending nearly six months outside of the lab, social distancing measures made it difficult for Ryan to finish up his doctoral work. If an experiment failed, an entire week of work could be lost because of the need to stagger attendance. Ultimately, the team moved to a larger unoccupied space close by in order to continue their work.

How will the MYCA prize money be used?

After completing his doctorate, Ryan had planned to put all efforts into his start-up company ThorTech based on the research he contributed to. However, the transition from graduate researcher to start-up co-founder is quite an expensive one.

«It [the prize] couldn’t have come at a better time! I’m just now starting to appreciate how expensive transitioning [to industry] is.»

Ryan Jansonius

MYCA 2021 Winner and Ph.D. Candidate, University of British Columbia

He wants to take some time off to work on the company before investment capital comes in, and the prize money will be instrumental to help him do this. Additionally, a bit of rest and recharge is needed after finishing his degree!

Ryan defends his Ph.D. at the University of British Columbia in May 2021, and we wish him the very best of luck. To learn more about the research of Ryan and his team, selected peer-reviewed literature is provided below.

Selected literature for further reading:

  • Sherbo, R.S.; Delima, R.S.; Chiykowski, V.A.; et al. Complete electron economy by pairing electrolysis with hydrogenation. Nat. Catal. 2018, 1, 501–507. https://doi.org/10.1038/s41929-018-0083-8

    This is the first article published on the Thor reactor.

  • Sherbo, R.S.; Kurimoto, A.; Brown, C.M.; et al. Efficient Electrocatalytic Hydrogenation with a Palladium Membrane Reactor. JACS 2019, 141, 7815–782. https://doi.org/10.1021/jacs.9b01442

    Thor enables ~65% more energy efficient hydrogenation reactions than can be achieved using normal electrochemical hydrogenation methods.

  • Delima, R.S.; Sherbo, R.S.; Dvorak, D.J.; et al. Supported palladium membrane reactor architecture for electrocatalytic hydrogenation. J. Mater. Chem. A 2019, 7, 26586–26595. https://doi.org/10.1039/c9ta07957b

    This article describes a design for palladium membranes that uses 25x less palladium than conventional Pd foils.

  • Jansonius, R.P.; Kurimoto, A.; Marelli, A.M.; et al. Hydrogenation without H2 Using a Palladium Membrane Flow Cell. Cell Reports Physical Science, 2020, 1, 100105. https://doi.org/10.1016/j.xcrp.2020.100105

    This article shows a designed and validated scalable flow cell architecture, enabling 15x faster, and 2x more efficient hydrogenation reactions.

  • Huang, A.; Cao, Y.; Delima, R.S.; et al. Electrolysis Can Be Used to Resolve Hydrogenation Pathways at Palladium Surfaces in a Membrane Reactor. JACS Au 2021, 1, 336-343. https://doi.org/10.1021/jacsau.0c00051

    Thor can also be used to resolve complex reaction mechanisms by depositing nanoparticles on the surface of the membrane.

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

Special thanks go to Ryan Jansonius for taking the time before his doctoral defense to contribute to this article.

Fire and ice: discovering volcanic eruptions with ion chromatography

Fire and ice: discovering volcanic eruptions with ion chromatography

by | Apr 19, 2021 | Analysis, Company, Sampling

Some answers lie deep beneath the ice, waiting to be discovered.

Performing environmental chemistry research has taken me to the most remote places on Earth. In my doctoral studies, I was fortunate enough to handle samples from the South Pole and to perform my own research in Greenland, and later in Antarctica for my post-doc. What were we searching for, that took us to the middle of nowhere?

Volcanic eruptions are pretty unpredictable. Among the more active and aesthetic volcanoes with lava flows are Mount Etna in Catania (Italy), Kilauea on the large island of Hawaii (USA), and more recently Mount Fagradalsfjall in Iceland. When smaller events occur, people travel from all over to view this natural wonder. However, not all eruptions are equal…

Depending on a number of factors including the height of the eruption plume and the composition of the emissions, volcanic events can have quite a significant effect on the global climate. The Volcanic Explosivity Index (VEI) is a logarithmic scale used to measure the explosivity value of volcanic eruptions and categorize them from 0 (effusive) to 8 (mega-colossal). The largest of these events in the past century was the 1991 Pinatubo eruption in the Philippines (VEI 6, colossal). The cloud column reached high into the stratosphere, ejecting huge amounts of aerosols and gases, including sulfur dioxide (SO2) that scatter and absorb sunlight. This led to a measured global cooling effect for nearly two years after the eruption ended. Images of cloudless days at noon during this time showed a flat white hazy sky, indicative of the scattering effect of high-altitude sulfur aerosols.

Other large volcanic eruptions have led to periods of famine as well as enlightenment. It is said that the fantastic skies resulting from Krakatoa in 1883 (VEI 6, colossal) inspired Edvard Munch to paint his well-known masterpiece The Scream. If you’re familiar with Frankenstein, you can thank Mary Shelley for writing it during the wintry «year without a summer» in 1816, a result of the eruption of Mount Tambora (VEI 7, super-colossal).

Solving a mystery at the ends of the Earth

This cold period has been studied at length by several research groups and methodologies. In fact, the preceding decade had been found to be abnormally cool, however no record of another volcanic eruption was immediately apparent. Ultimately, it was pristine ice that held the clue that solved this mystery, and many others.

The sulfur dioxide emitted during volcanic eruptions is oxidized to sulfuric acid aerosols in the atmosphere, and depending on the height they reach, they can reside for days or even up to years. The deposition of volcanic sulfate on the polar ice sheets of Antarctica and Greenland preserves a record of eruptions via the continuous accumulation of snow in these areas. Therefore, records of volcanic activity can be found in polar ice cores by measuring the amount of sulfate. A fantastic way to determine sulfate, along with other a suite of major anions and cations in aqueous samples even at trace levels is with ion chromatography (IC).

The author holding a 1-meter long ice core drilled in Summit Camp, Greenland (left) and Dome Concordia, Antarctica (right).

Of course, gases can also be measured as they are trapped in the spaces between snowflakes, which are then compacted into firn and subsequently locked into the ice sheet. However, the time resolution for this is not fine enough for such volcanic measurements, nor is the volume of gas large enough to make an accurate estimate of the volcanic origin.

Gases trapped in the ice can be measured with special instrumentation and give insight into the prehistoric atmosphere.

Drilling ice cores for ion analysis is not a simple business. The logistics are staggering – getting both the field equipment and properly trained personnel to the middle of the ice sheet takes a sophisticated transportation network and cannot follow a strict schedule because Mother Nature plays by her own rules.

A complete medical checkup is necessary from top to bottom, as medical facilities can be rudimentary at best. This includes bloodwork, heart monitoring, full dental x-rays, and more (depending on your age and gender). It can take several days to evacuate a hurt or sick person to a proper hospital and therefore being in good health with an up-to-date medical record is part of being prepared for this type of remote work.

Equipment must be shipped to the site weeks or months in advance, often left at the mercy of the elements before being assembled again. Hopefully, everything works. If not, you must be very resourceful because there are no regular shipments and replacement parts are difficult to come by.

Boarding passes given to polar support staff leaving from Christchurch, New Zealand to McMurdo Station (USA) in Antarctica.

Ice cores obtained from polar areas and other remote places have been used for decades to analyze and reconstruct past events. Many considerations must be made regarding where to drill, how deep to go, and so on. The geographic location is of critical importance for several reasons including avoiding contamination from anthropogenic emissions, but also for its annual snowfall accumulation rate, proximity to volcanoes and even to other living beings (like penguin colonies, in the Antarctic).

Remote drill site based outside and upwind of Summit Camp, Greenland.

A fine resolution record of sulfate from ice cores drilled in Greenland and Antarctica has led to the discovery of previously unknown volcanic events. Ion chromatography with a dual channel system allows the simultaneous measurement of cations and anions from the same sample. When dealing with such critical samples and small volumes, this is a huge benefit for complete record keeping purposes. With the addition of automatic sample preparation like Metrohm Inline Ultrafiltration or Inline Dilution, human error is eliminated with a robust, time-saving analysis method.

Learn more about Metrohm Inline Sample Preparation (MISP) here!

Metrohm Inline Sample Preparation (MISP)

Over the past two decades, the time resolution for data from ice core analysis has increased significantly. Conductivity used to be the measurement of choice to determine large volcanic events in ice cores, as it is difficult to see (unaided) the deposits of tephra from many eruptions, contrary to what you may think. The conductivity of sulfuric acid is higher than that of water, but conductivity is a sum parameter and does not disclose exactly what components are in the sample.

Tephra layers deposited by a volcanic eruption in Iceland.

Even when IC began to build traction in this space, the sample sizes did not allow researchers to determine monthly variations, but yearly approximations. This meant that any smaller sulfate peaks could have been overlooked. Researchers have tried to overcome this by matching records from ice cores around the globe to estimate the size, origin, and climatic impact of past volcanoes. Unfortunately, when the drill site is located close to active volcanism (as is the case with Greenland, downwind from Iceland), even smaller eruptions can seem to have an oversized effect.

Drilling into the ice always requires keeping track of the top and bottom ends of each meter!

The enhanced time resolution now possible with more sophisticated sample preparation (i.e. continuous flow setups for sample melting without contamination) for small volume IC injection allows for more accurate dating of volcanic eruptions without other apparent historical records.

Selected data from a drilled ice core, measured by IC. Trace analysis is necessary due to the low concentrations of ionic species deposited in remote locations. Annual layer counting was possible here, as shown with the yearly variations in several measured analytes. Grey bars represent the summer season.

Depending on the annual snowfall at the drill site and the depth of the core drilled, it can be possible to determine which month in a given year the deposition of sulfate from a volcanic eruption occurred.

This information, combined with other data (e.g., deposition length) helps pinpoint the circulation of the eruption plume and estimate the global impact. Aside from this, other data can be gained by measuring the isotopic composition of the deposited sulfate to determine the height of the eruption cloud (a more accurate method to confirm stratospheric eruptions), but that is beyond the scope of this article.

Storing hundreds of meters of ice cores during a summer research campaign in Antarctica.
Summers at Dome Concordia are not balmy, as shown in the temperature data (-54.3 °C wind chill!).

Using ion chromatography, it is possible even in the field to accurately determine the depth where specific volcanic events of interest lie in the ice. Then several ice cores can be drilled in the same location to procure a larger volume of ice to perform more detailed analyses.

My ice core research laboratory in Antarctica. Left: Metrohm IC working around the clock in the warm lab. Right: the ice core sample processing area in the cold lab (kept at -20 °C).

Learn more about the robustness of Metrohm ion chromatography on our website!

Metrohm Ion Chromatography

To solve this particular mystery, it was the combination of matching the same sulfate peak measured via IC in ice cores from both polar regions along with confirming the stratospheric nature of the eruption that led to the discovery of a previously unrecorded volcanic event in the tropics around the year 1809 C.E.

Transporting insulated ice cores back home for further research takes the cooperation of scientists, camp support staff, and the government. If flying, the entire flight must be kept cold to ensure the integrity of the ice. Any unlucky person catching a ride on a cold-deck flight must bundle up!

Cold period was extended by a second volcanic eruption

In fact, the stratospheric Tambora eruption in 1815 was already preceded by another huge climate-impacting event in the tropics just a few years before. This combination led to one of the coldest periods in the past 500 years. The data obtained by IC measurements of ice cores was instrumental in this discovery, and many more in the past few years.

Leaving the Antarctic continent can happen in a number of ways: by boat, military aircraft, or a plane. I was lucky enough to catch a first class ride on a government plane, with the added bonus of having a very interesting flight plan on screen.

High impact data

Other new volcanic eruptions have been discovered in the ice core record as the analytical technology improves. Their eruption dates can also be more accurately determined, helping to explain which of them had a climatic impact or not. This information helps to improve the accuracy of climate models, as the high altitude sulfate aerosols resulting from large eruptions reflect the sun and cause long periods of global cooling. It is for this reason that some groups have proposed a form of geoengineering where controlled amounts of sulfur gases are injected high into the atmosphere to mimic the effects of a stratospheric eruption.

In conclusion

I hope that this brief summary of a niche of environmental research with ion chromatography has piqued your interest! Maybe the inspiration of knowing that such roles exist will push other young scientists to pursue a similar career path. Chemistry education does not always have to happen indoors!

Robust ion chromatography solutions

Metrohm has what you need!

Find your perfect IC solution here

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