Potentiometric Titrators

Hanna Automatic Potentiometric Titration Systems

Hanna’s automatic titrators are designed to perform a wide variety of potentiometric titrations with high accuracy, flexibility, and reproducibility, allowing the user to obtain both accurate results and high-speed analysis. These titrators can perform fixed endpoint or equivalence point titrations and direct measurements by measuring the pH/mV and temperature of the sample. Reports and methods can be transferred to a PC via a USB interface, saved to a USB storage device, or printed directly from the titrator. An external keyboard can also be attached for added convenience.

Principle of Titration

Titration is used in analytical chemistry to determine the amount or concentration of a substance, known as the analyte. Titration is a quantitative measurement of an analyte in solution by its complete reaction with a reagent. 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. This 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, conductivity, 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. Titrations are based on chemical reactions which must fulfill four requirements:

The reaction between the analyte and the titrant must occur quickly, without a secondary reaction
The reaction must go to completion
The reaction must have well-known stoichiometry (reaction ratio)
Must have a convenient method of endpoint detection

Titrations are highly precise and can provide many advantages over alternative methods. Titrations are quickly performed and require relatively simple apparatus and instrumentation.

Automatic Titration

Automatic titration is done with instrumentation that delivers the titrant, stops a the endpoint and calculates the concentration of the analyte automatically. Automatic titrators are best for accurate and repeatable results, as an electrochemical measurement is used to determine the endpoint as opposed to a subjective color indicator.

Analyses that can be performed by potentiometric automatic titrators include:

Acid-base titrations
Oxidation reduction titrations
Complexometric titrations
Precipitation titrations
Non-aqueous titrations
Argentometric titrations
pH, ORP, and Ion selective measurements

The required equipment for automatic titration include an automatic titrator equipped with a burette, a standardized titrant, a volumetric pipette (to measure the sample volume) or analytical balance (to measure or weigh a sample), a beaker, a sensor, and a stirring mechanism.

The automatic titrator must have an accurate liquid-dispensing system. In high accuracy systems, this is typically a motor-driven piston burette, a valve system to switch between titrant inlet and outlet, and a titration tip to dispense the titrant into the sample solution. These three main subsystems must be as accurate as possible, with very low gear backlash in the burette drive mechanism, low piston seal flexing, accurate burette glass cylinder diameter, low dead volume in the valve, minimal evaporation/permeation and chemically resistant tubing.

Standards and Standardization

One of the substances involved in a titration must be used as a standard for which the amount of substance present is accurately known. The standard can be present either in the form of a pure substance or as a solution. The titrant solution can be standardized in two ways; using a primary standard, or more commonly, titrating it against a previously standardized solution.

HI931 Automatic Potentiometric Titration System (pH/mV/ISE)

The HI931 Automatic Titrator is the answer to your dedicated titration needs. Titrate for a variety of measurements at the push of a button including acids, bases, redox, and selective ions. With no additional programming upgrades to purchase, you can start measuring right away.

Multiple Titration Types

Paired with the right electrode, this potentiometric titrator can perform any number of standard titrations, including pH and mV tests with fixed endpoints or single equivalence points.

HI932 Automatic Potentiometric Titration System (pH/mV/ISE)

The HI932 Advanced Automatic Titrator is the answer to your advanced titration needs. Titrate for a variety of published methods at the push of a button, as well as perform direct measurements and back titrations for complex samples. For those that require greater automation, pair your HI932 with the HI922 Autosampler for the most accurate results with the least amount of effort.

Multiple Titration Types including Back Titrations

Paired with the right electrode from our sensor line, this potentiometric titrator can perform any number of standard titrations, back titrations as well as perform direct pH, ORP, and ion selective readings.

Multiple equivalence point detection

Method Sequencing

HI922 Autosampler Compatible

Works seamlessly with the HI922 Autosampler for automation of up to 18 samples

HI931 Rear connections

HI931 offers support for one analog board to allow an electrode, a stirrer and up to two burettes to be connected to one unit

HI932 Rear connections

HI932 offers support for two analog boards, allowing up to two electrodes, two burettes, and two stirrers to be connected to one unit.

Superior Design, Superior Results

Body

The Cycoloy® body is durable, heat-resistant, and resists staining. Menu buttons are part of the display, making it fully sealed and easy to clean.

Size

This new generation of titrator features a 50% smaller footprint than the HI902 Automatic Titrator for maximum use of your lab space. Use it in any sized space while providing accurate and consistent results.

Display

A high contrast LCD display makes every character on the display stand out and the wide viewing angle allows measurements to be seen from any angle. The backlight is adjustable for perfect viewing and a backlight saver option protects the display during periods of inactivity.

Experience

Virtual keys present on the display allow for simple and quick navigation between screens and menus without getting lost in a nest of information. If you need additional information about a screen, simply press the dedicated button for help.

Titrator Capabilities

Burrettes and Dosing System

Clip Lock™ exchangeable burette system

With Hanna’s Clip-Lock™ burette feature, it only takes a few seconds to exchange titrants and reagents preventing cross-contamination and saving time.

Multiple burette sizes

These titrators are supplied with a 25 mL burette but may be equipped with a 5 mL, 10 mL, or 50 mL burette. Each burette is constructed with a ground glass syringe and chemically resistant PTFE plunger.

Precision Dosing Pump

Our unmatched 40,000-step piston driven pump is capable of dosing extremely small and highly accurate volumes of titrant or reagent.

Chemically Resistant Tubing

Aspiration and dispensing tubes are constructed of durable, chemically resistant PTFE and feature a light-blocking polyurethane outer sleeve to protect light sensitive reagents.

Automatic Reagent Addition

A peristaltic pump or a second burette may be programmed to volumetrically dispense reagent prior to titration or direct measurement or aspirate post-analysis. This helps achieve consistent and accurate results and prevents operator errors such as incorrect volumes or forgetting reagent addition.

Data Features

Data Storage and Transfer

Store up to 100 titration and pH/mV/ISE reports. Transfer titration methods and reports, or acquire software upgrades through use of a conveniently located USB port or direct connection to a PC. Easily convert titration methods from our software to an LMS friendly format.

Flexible GLP Management

All necessary GLP (Good Laboratory Practice) information is recorded with each sample including sample identification, company and operator name, date, time, electrode ID codes, and calibration information.

Enhanced Security Options

Administrative users can set a PIN code on the device protecting against unauthorized access. Titration method options and results are tamper-proof while a non-administrator operates the titrator, ensuring records remain safe, secure and traceable.

HI922 Autosampler Connectivity (HI932)

The HI932 works seamlessly with our HI922 Autosampler featuring 16 or 18 sample tray options, automatic tray identification, and automatic beaker detection. Up to three peristaltic pumps for reagent addition and removal can be connected and real-time analysis and sequencing progress is visible on the HI932 display as well as indicated by the LED lights of the Autosampler.

Click “Features” above to learn more!

Designed for Dynamic Environments

Don’t worry about small spills in the laboratory with built-in spill handling. An external gutter system protects important connections and interior trays safeguard internal electronics.

Electrode Holder

This electrode holder can hold up to 3 electrodes, 4 tubes, and 1 temperature probe at any given time. The holder is angled and the stirrer is removable for access to smaller volume titrations without hassle.

Use electrodes with different diameters when needed by simply changing the electrode guide. No need to move electrodes around, get the best tube alignment for your titration with a rotating holder

For a more compact design, the electrode holder is mounted directly onto the titrator body. The press-to-release button makes for simple height control. Need to save more space? Just reverse the holder to accommodate larger beakers.