Titration

In analytical chemistry, titration is used to determine the amount or concentration of a substance known as an analyte. In a titration, one reagent (the titrant) is slowly added to a solution containing the species being measured (the analyte). As it is added, a chemical reaction occurs between the titrant and analyte. The point at which the reaction is complete and an equivalent quantity of titrant and analyte are present (a stoichiometric equivalent) is called the equivalence point.

The equivalence point can be determined by a chemical indicator that is also present in the solution, or by a measurable physical change in the solution, like pH, electrode potential, or light absorption (color). In practice, an abrupt change of this physical property signals the end of titration, called the endpoint. The purpose of titration is to determine the quantity or concentration of an analyte with a known concentration and volume of a titrant.

Automatic titration is done with instrumentation that delivers the titrant precisely, stops at the endpoint, and calculates the concentration of the analyte automatically. Titration systems include both potentiometric and Karl Fischer titrators. Potentiometric systems include application specific mini-titrators for basic analysis and advanced titrators that can accept pH, ORP, ISE and photometric probes. The advanced titration systems offer the ability to connect to an autosampler for high throughput testing. For water content analysis Hanna offers Karl Fischer titrators including both volumetric and coulometric versions.

 

Potentiometric Titrators

Potentiometric titration systems include versions with one or two analog input boards for probes and versions with one or two dosing pumps. All titrators are pre-programmed with Hanna methods for routine standardization of titrants. Optimized methods are available for various industries. A wine titrator is available that has titratable acidity, sulfur dioxide, reducing sugars, and YAN methods that are commonly used. Titrators are available that allow linked methods such as with salt and acidity on food products. All titrators feature linear or dynamic dosing and te otption for a fixed end point or equivalence point determination.

 

 

Karl Fischer Titrators

Volumetric and Karl Fischer titration systems are available for measuring water content in a variety of samples. The KF titrators have a sealed solvent handling system for emptying and filling the titration vessel. The meters have automatic drift correction to maintain a dry cell when they are not in use. The KF titrators have powerful, built-in algorithms for termination criteria based on fixed mV endpoint or absolute/relative drift.

 

 

Mini-Titrators

Hanna’s innovations include the development of application specific titration systems that have been simplified for a variety of users and are economical as compared to the titration systems with customizable methods. These meters use a piston style dosing system for accuracy and pre-standardized titrants for simplicity. Most systems (acid/base) offer the ability to use the meter as an advanced pH meter as well. The mini-titraors include versions for sulfur dioxide, formol nitrogen, and titratable acidity for wine. Mini-titrators for the acidity of juices and alkalinity of water are also available.

 

 

Auto-Samplers

Below are autosamplers used with the potentiometric titration systems for high throughput testing. The autosamplers are available with trays that can hold 16 or 18 samples. The trays are chemically resistant and dishwasher safe. The autosamplers can be configured with up to three peristaltic pumps for reagent addition and one diaphragm pump used for rinsing of the probes. The samplers allow for customized sequences to be created.

 

 

 

 

Copyright ©2020 Hanna Instruments, Inc.