Titrations are a laboratory technique which can be used to determine the concentration of an unknown reagent using a standard concentration of another reagent that chemically reacts with the unknown. The process is highly suitable for automation due to the repetitive nature of the task. 

Additionally, automated systems present a safer solution when dealing with unknown concentrations especially when dangerous chemicals are present - the risk to personnel can be greatly reduced.

Finally automated solutions present a more reliable result, consistently performing the standardised actions, first time, every time.

Robotic Titration systems are complete solutions, they:

• Accept liquid samples.
• Deliver the titrant.
• Stop at the endpoint.
• Calculate the concentration of the analyte.
• Output data into existing LIMS systems.

• Perform a sequence of chemical additions, weighing, heating, cooling, mixing & cleaning actions
• Output liquid samples ready for elemental analysis.
• Can be linked to analysis machines e.g. ICP-OES, ICP-MS, Flame AAS etc.

Robotic systems such as this one have much greater sample processing rates in comparison to the old way using human processing. Robots are not limited to set working hours, they do not experience significant downtime, they have the ability to work 24 hours a day 7 days a week.

Technical Info: Detailed description of Chemistry Underlying a 4-Acid Digest

A typical process of titration begins with titrant, a known reagent of the examined analyte being placed in a calibrated burette. The analyte is constantly monitored for reaction using an indicator. At the point which the reaction occurs (the endpoint), a reading is taken from the burette indicating the exact amount that has been consumed when the endpoint is reached.

The endpoint is considered (ideally) to be the same as the equivalence point - the volume of titrant added in which the number of moles of the titrant is equal to the number of moles of the analyte (or a multiple thereof).

Instrumentation:
Manual titration is done with a burette, which is a long graduated tube to hold the titrant. The amount of titrant used in the titration is found by reading the volume of titrant in the buret before beginning the titration and when the endpoint is reached, and taking the difference. The most important factor for making accurate titrations is to read the burette volumes reproducibly. Automating this process ensures reproduceable, error free results.

For repetitive titrations, autotitrators with microprocessors are available that deliver the titrant, stop at the endpoint, and calculate the concentration of the analyte. The endpoint is usually detected by some type of electrochemical measurement. Some examples of titrations for which autotitrators are available include:

• Acid or base determination by pH measurement with potentiometric detection.
• Determination of water by Karl Fischer reagent (I₂ and SO₂ in methyl alcohol and pyridine) with coulometric detection.
• Determination of Cl in aqueous solution with phenylarsene oxide using amperometric detection.

• Potentiometer - monitor electric potential in reactions
• pH Meter - monitor amount of H+ ion present in solution (very accurate, easily automated)
• Conductance
• Precipitation
• Isothermal titration calorimeter - monitor heat consumption or production in reactions
• Thermometric titrimetry - monitor the rate of temperature change
• Amperometry - monitor change in current (useful when the excess titrant can be reduced, ignores precipitate matter)

Robotics in the Laboratory:

Most analytical laboratories perform analyses by hand which exposes staff to harmful chemicals as well as repetitive mundane work. However in recent years, developments in technology have arisen in the field of robotics and automation, and many labs are now converting their systems toward automation.

Laboratories around the globe are turning their sights to robotics and automation due to the ability to increase efficiency and reproducibility for sample analysis. Robots provide a means to deliver accurate, repeatable results with minimal time wastage as well as minimal materials wastage. Due to the ability of robots to be precisely programmed and their ability to follow complex algorithms, heating times and process times are able to be optimised according to requirements of specific samples.

Through the use of robots and simple automation, it is easy to perform many laboratory processes. Especially processes which mainly involve pick/place, dosing, weighing, heating, cooling, sample transfer and mixing actions, which covers most laboratory procedures.

For more information on how Argon Lab Systems will be suitable for your application contact us.