Is your analysis volume growing?
Are your customers’ specifications getting stricter?
You are not alone.
Analytical requirements are growing across many industries and customer standards are increasing.
Fortunately, titration is a measurement method that can be easily automated to provide a wide range of benefits.
Additionally, automated titration technology is becoming more accessible and affordable.
Many businesses see short payback periods as well as improved competitiveness and reduced business risk. Good analytical systems are now a competitive requirement for many industries.
Change is hard though.
To help businesses prepare a business case for automation, we have compiled a brief overview of the benefits of automated titration.
First, let’s recap how titrations work.
In titration, a solution of known concentration, called the titrant, is added to react with the sample you would like to measure, called the analyte.
The titrant is added until an endpoint is reached, which signals the end of the titration.
In many manual titrations, a chemical indicator signals the endpoint.
The chemical indicator changes colour once the titrant reacts with all of the analyte (i.e. all of the acidity or salt in a food sample). These colour changes can be difficult to see, and may be interpreted differently between users.
In an acidity titration, a base such as NaOH is added to a sample.
At the titration endpoint, phenolphthalein changes from colourless to pink at pH 8.2. However, one person’s idea of “pink” may be different from another person’s “pink,” resulting in inconsistent results among lab technicians.
When working with colored samples, like food, detecting this color change becomes even more difficult. The milk sample below has been titrated to 8.2 (left) and unreacted (right).
Top 5 Benefits of Automated Titration
Automatic titration fixes many of the issues with manual titration and brings new benefits.
Benefit 1: Endpoint detection based on data not opinion
Automatic titrators use sensors as the indicator. These sensors are sensitive to the amount of analyte in your sample.
We use a pH electrode in acidity titrations and a silver-sulfide ion-selective electrode for salt (NaCl) titrations.
These electrodes work by detecting the large voltage change resulting from the chemical reaction at the point where the all of analyte is consumed by the titrant.
The automatic titrator then uses an internal algorithm to analyse this data, and determine the exact volume at the titration endpoint. This has the advantage of more sensitive, non-subjective endpoint detection, leading to titrations that are accurate based on data.
Benefit 2: Better accuracy and reproducibility
Manual titrations use a glass burette to add the titrant to the sample. A stopcock, a valve that can be manually opened or closed to permit titrant flow, controls the burette’s dosing.
However, the accuracy of these doses is entirely dependent on analyst’s skill.
Under ideal conditions, this can produce reasonably accurate results, but is less reliable when comparing results between different users with varying levels of experience.
With automatic titration, a high precision piston-driven pump performs titrant additions. These pumps are capable of doses as small as 0.001mL. This provides greater resolution than would be possible with manual titration.
In addition, since an automatic pump is dosing, the results will not be influenced by analyst’s skill. Instead, user involvement is limited to:
- measuring the sample
- submersing the electrode and titrant dosing tip
- pressing “start”
Each sample is titrated in exactly the same way since the control parameters of the titration are preprogrammed.
Benefit 3: Reduced titrant and sample usage
To obtain accurate results, the lower dosing resolution typical of manual titrations is typically offset by a larger sample size. The high titrant volume compensates for the inability for small doses resulting in increased chemical use.
The increased chemical consumption is a big issue especially if the titrant is expensive.
Salt and acidity are common analyses in food. Salt is determined by titration with silver nitrate – a very expensive titrant.
Automatic titration can significantly reduce titrant consumption without compromising on the precision of the results.
Due to the high dosing accuracy, methods can be optimised to use smaller sample sizes and as a result, less titrant.
Look for dynamic dosing for highly efficient titrant usage
The initial startup cost of automatic titration is higher, a major payoff can come in the form of chemical cost savings.
The cost of sample wasted can also be an issue. The availability of linked methods in some applications allows two titrations to be completed on one sample.
Benefit 4: Time savings and reduced need for technical skills
The most obvious benefit behind automatic titration is the saving of active bench-time.
Manual titrations require the full attention of the person performing the test, as they are adding titrant and watching for the endpoint. Since the analyst is occupied for the entire duration of the test, he/she cannot perform other tasks until the titration is complete.
When titrations are automated, the user is no longer involved in the titration process once the sample is prepared and the titration is started. While the titration progresses automatically, the user can prepare the next titration sample, run another test, or perform any other job functions. All the user has to do is return to the titrator at completion and obtain the result.
However, in reality, there may also not be enough time for the technician to complete another task while the titration is progressing.
To realise all the potential time savings, it is often necessary to automate sample handling with an autosampler, allowing higher throughput and longer available time intervals to complete other tasks.
Benefit 5: Traceability
Even if a manual titration is performed correctly, the result is not easily traceable due to the lack of a report. Manual reporting is feasible, but can be prone to errors in transcribing and transferring data and is otherwise cumbersome.
Automatic titration systems are capable of generating an automatic report for each titration.
The report is customizable to include results, titration parameters, dose-specific data points, and good laboratory practice (GLP) information. The extensive report offers confidence in the validity of titration data and allows for easy recordkeeping.
Overall, automatic titration systems provide an easy way to increase throughput, accuracy, traceability and peace of mind in the laboratory or in production.
There is some initial capital investment but this investment may not be as high as you think.
For high volume applications, the savings on time and reagents alone is sufficient to provide a return on the investment for an advanced automatic titration system.
When working with Hanna Instruments for your automatic titration needs, our Australian office provides not only the instrument, reagents, and electrodes, but also, the technical support and training make sure that you have a smooth transition to automation.