Titrators: Myriad Methods for Quantifying Unknowns

 Those whose only brush with titration came in a freshman chemistry lab may be surprised to learn the significance of titration in companies that manufacture materials, drugs, foods, and beverages.

David Minsk, president of Hanna Instruments (Woonsocket, RI), defines a titrator as “a sophisticated delivery system that performs stoichiometry. It’s a tool that provides better repeatability, accuracy, and efficiency than manual titration.”

There are two major titrator types: potentiometric acid-based designs and Karl Fischer titrators. Those in the first group, which use a pH or redox probe, resemble pH meters in their ability to derive acid strength and total acidity; Karl Fischer titrators measure water content in foods, materials, biofuels, etc.

Most titration work occurs in quality control (QC) laboratories. A survey found that 75 percent of titrators are used in QC, 20 percent in research, and 5 percent in clinical labs. More than half of those surveyed had more than one titrator, with 10 percent owning four or more. Of specific titration modes, more than half fall under the “potentiometric” category, and 21 percent each for volumetric and coulometric Karl Fischer titrations.

All those surveyed considered instrument cost during the purchasing process. This is not unusual when you consider that everyone who performs titration professionally has at one time done it on the cheap with a burette, an Erlenmeyer flask, and either a colorimetric indicator, pH paper, or a pH meter. Dedicated titration systems range in price from about $5,000 to more than $100,000. Yet only 10 percent of those surveyed listed instrument cost as the top reason for choosing one titrator over another.

After price, our readers considered performance, reliability/maintenance, service, support, and ease of use when purchasing a titrator. Experience with a particular vendor or product line was the number-one factor (53 percent) in selecting a specific instrument.

Bucking the trend

Don Vreeland, president of Analyticon Instruments (Springfield, NJ) sums up developments and trends in titration as “flexibility and versatility.” Different industries have different titration needs, Mr. Vreeland explains. “These range from low-cost, easy-to-use, single-type titrations to complex, multi-chemistry, multielectrode, multi-sample, and multireagent analysis.” The point: Select your titrator with current needs in mind, and perhaps with a thought toward expanding future capabilities.

A major trend for lab instruments in general, and titrators in particular, has been to supply each instrument with a computer for data acquisition, logging, and massaging. Not all companies have gone along with this approach. “There is no need to have a computer attached to each instrument in the lab,” Mr. Vreeland says. “Our instruments come with software for downloading and archiving data through an RS-232, a LAN, or USB interface, but the computer is not required to operate the instrument.”

Read more at Lab Manager Magazine