Automatic potentiometric titration system - Mettler Toledo
Water is intensely purified and treated by water authorities before being ready for thousands of families. Everybody expects clean and safe tap water when turning on their taps. A water quality analysis center in Shanghi, China excels in its water testing and analysis with fully automatic potentiometric titration.
Traditional Water Quality Analysis
In order to ensure water hygiene and safety for thousands of households, the center must deal with many different water samples daily, including source water, treated water at different process stages and end water. Every water sample requires a series of analyses. The main detection parameters are: total hardness, chloride content, residual chloride, COD (chemical oxygen demand) plus alkalinity.
The traditional method is classical manual titration. Previously, analysts stood by the experiment table, one hand operating the glass titration burette, the other shaking the conical bottle in which chemical reactions were constantly happening, observing solution color change. Past experimental data was manually logged.
Automatic Potentiometric Titration
METTLER TOLEDO has become a welcomed new partner at the center with a fully automatic potentiometric titration system – the T50 Excellence Titrator and the Rondo 20 fully automatic sample changer. Twenty sample beakers are put on the sample changer, the shortcut key is pressed and the test begins: the propeller stirrer on the titration stand mixes the chemical substances whilst the dosing unit begins to dispense titrant. An electrode successfully detects the end point reaction, freeing up operators. When the test is completed, all relevant experiment information is printed out in order to be compliant with GLP (Good Laboratory Practice). By the time the report is printed, the instrument has already cleaned the detection electrode and propeller stirrer to be ready for the next sample.
The centre periodically uses a standard substance as a sample to examine the reliability and accuracy of each instrument. The T50 Titrator obtains precise results in every ‘trial test’ with measurement results consistently complying with standard values. The original manual titration burettes are correct up to ±0.01 ml while the dispensing precision of the automatic titrator can be raised to 0.05 μl. In addition, manual titration depends upon color change to judge end points leading to errors due to operator differences. Greater errors can occur for titration with nonapparent color change or those generated by precipitation. Potentiometric titration eliminates operator errors.
’One-Click’
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