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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:

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!

Discover even more

about combined analytical systems from Metrohm

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

Virus detection using screen-printed electrodes

Virus detection using screen-printed electrodes

With significant global viral outbreaks becoming the norm rather than generational outliers, it is imperative that fast, sensitive, and cost-effective testing is available to the masses. It is only by a concerted effort of testing and tracing that viral outbreaks can be effectively controlled before becoming global pandemics.

Screen-printed electrodes (SPEs) allow rapid, widespread testing of populations for infectious disease, without the need of skilled personnel or burdensome equipment in the field. The possibility of point-of-care (POC) testing with SPEs has been exhibited in several recent studies. Metrohm DropSens, as a manufacturer of SPEs as well as their compact measuring devices, is the right partner for virology research projects—big and small. With a high production capability, combined with a valid ISO 13485 certification «Manufacturing of sensors for medical devices», this means testing procedures developed on DropSens SPEs can be reliably scaled up for larger operations, with easier approval by the Food and Drug Administration (FDA). As the leading brand in the market for this printing technology, Metrohm DropSens can design custom-made SPEs and offers the expertise and exceptional customer support needed for complicated projects at scale.

Viral outbreaks and human health

Unlike the majority of bacteria, most viruses cause disease. Viruses, however, cannot survive without hosts, and therefore spread easily especially in densely populated areas. While bacterial infections can be fought with a range of antibiotics, viruses require specific vaccines, which can be extremely difficult to manufacture.

Several viral outbreaks have caught global attention and attracted calls for faster, more accessible testing, including Ebola, avian influenza virus (H5N1, H1N1, and others), hepatitis, malaria, noroviruses, dengue, adenovirus, SARS (severe acute respiratory syndrome, HIV (human immunodeficiency virus), and even HPV (human papillomavirus). While some are capable of killing their human hosts in a relatively short timespan, others can linger for decades.

One commonality between these diseases is that they have all been successfully tested with disposable, custom-made SPEs from Metrohm DropSens.

The global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more commonly known as «COVID-19», has monopolized the headlines for months. Each country’s response has varied: from the tactics of encouraging normalcy to attempt quicker herd immunity, to extremely strict quarantine measures, especially for the elderly, and the closure of borders and non-essential industries. However, the most effective way to trace and contain the spread of viruses is through comprehensive testing.

General viral testing methods and their drawbacks

The importance of testing for the presence of harmful viruses in the population cannot be overstated. In order to stop the spread of especially communicable diseases, testing must be accurate, reliable, timely, affordable, and of course widely available.

Viral testing can be accomplished via several different methods, including virus isolation cultures, enzyme-linked immunosorbent assay (ELISA), and other molecular methods like polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR).

High costs limit the affordability and overall availability of such tests to the general population, especially for poorer communities. Complicated analytical procedures require trained professionals, specialty chemicals, and bulky instruments, which may not be available in all areas. On top of this, the waiting time between test and result is prohibitive – sometimes taking several days, which could mean the difference between life or death.

Benefits of electrochemical testing

Recently, initiatives for diagnostic testing methods have been launched by agencies such as the WHO to create faster, more accurate, affordable tests—especially in low-resource areas. For these reasons, electrochemical testing methods have been developed on disposable screen-printed electrodes, exhibiting major promise for fast, affordable, precise testing directly at the point of care.

Speed

The rapid testing capabilities of electrochemical biosensors is among one of their greatest advantages. Results are obtained within minutes, rather than hours or days with other conventional techniques. Waiting for days for results can lead to further viral communication in the community, or even death in the absence of proper care. Earlier response is vital to stopping the spread of disease and the key to saving lives.

Limit of detection

Specific electrochemical detection techniques (e.g., voltammetric or amperometric analysis) already allow for the detection of low analyte concentrations. The high adsorption capabilities of carbon-based working electrodes where certain recognition elements are attached play a key role in the improvement of sensitivity. To further decrease the detection limit, signal amplification by chemical or electrochemical catalytic reactions are commonly used.

Ease of use

The compact size of the measuring device, not to mention the SPEs themselves, equates to complete portability for testing on the go. Simply add a small volume of sample to the electrode, insert it into the measuring device, and receive results about viral exposure in minutes.

Cost

The low cost per test is a great advantage of using screen-printed electrodes for virology studies. Each SPE is meant to be disposable after a single use, ensuring a fresh substrate for every sample. The affordability and portability of SPEs and their measuring devices makes this technique much more attractive for economically depressed areas or regions without an abundance of specialized testing facilities.

Regulatory approval

Metrohm DropSens is certified by ISO 13485 «Manufacturing of sensors for medical devices». This certification permits a simpler pathway to regulatory approval (such as by the FDA) and leads to quicker commercialization of validated tests developed on these products in the medical field.

Customization

Metrohm DropSens has the technology to develop screen-printed electrodes based on the individual needs of the customer. The configuration and dimensions of the electrodes are adapted to their specific requirements.

Selection of screen-printed electrodes manufactured by Metrohm DropSens.
Availability

The large-scale manufacturing capabilities at Metrohm DropSens guarantee a trusted, reliable source for the mass production of SPEs suitable for viral testing. With decades of electrochemical expertise, a worldwide distribution network, and top class after-sales support, the widespread commercialization of tests developed on these products is no problem.

Summary

Point-of-care testing with screen-printed electrodes allows rapid, widespread testing of populations for viral outbreaks at low cost and without the need for skilled analysts or complicated measuring equipment. Fast results mean quicker reaction times – for swift treatment, but also for tracing the spread of contagion and developing a concerted response before the situation gets more out of control.

Portability and the simplicity of use allows rapid testing with screen-printed electrodes in all situations, not only off-site in specialized laboratories with a skilled staff. Since SPEs are customizable, they can be modified and manufactured to suit the needs of all types of research groups.

Metrohm DropSens SPEs, which are ISO 13485 certified, means testing procedures developed on these products require shorter times to receive FDA approval and commercialization. The bulk manufacturing capability of Metrohm DropSens guarantees a stable commercial source for custom-made SPEs and their measuring devices at any order size—big or small.

Metrohm DropSens: a complete solution provider

As a market leader in manufacturing reliable screen-printed electrodes as well as their measuring devices, Metrohm DropSens is the ideal partner for virology studies based on electrochemical testing, as well as for other research involving SPEs. For more information, Visit the Metrohm DropSens website at www.dropsens.com to have an overview of our products, capabilities, and additional peer-reviewed scientific literature featuring these electrodes and measuring devices.

For more information, visit the Metrohm DropSens website to have an overview of our products, capabilities, and additional peer-reviewed scientific literature featuring these electrodes and measuring devices.

Download our free white paper to learn more

Virus detection: Fast, sensitive, and cost-effective with electrochemical testing

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