Measurement by ion-selective electrodes (ISE) is particularly useful for the determination of the titration end-point, as they are unaffected by sample colour or turbidity. ISEs are inexpensive and typically, the cost per test is very small.
The Orion brand from Thermo Scientific is a world leader in ISE technology and its range of electrodes form the basis of the one analytical technique that gives direct measurement of both cations and anions – common ones like sodium, chloride, potassium, nitrate, calcium, sulphide and many more. Orion electrodes also measure dissolved gases such as ammonia, nitrogen dioxide and carbon dioxide. The application notes for specific subjects are available and can be requested free of charge to suit your application or situation from Orion’s exclusive agents Labotec.
For instance, one such paper “Determining the ammonia nitrogen in waste-water” gives a detailed account of methods employed for accurate measurements.
Indirect electrode methods greatly increase the number of species that can be measured. For example, aluminium, magnesium, manganese, nickel and zinc can be determined by titration.
Essentially hundreds of different analysis’s can be made faster and easier through electrode methods, applicable to diverse topics such as sewage treatment, drinking water, food processing, agriculture and biomedical research. Anyone unfamiliar with this branch of analytical chemistry can easily find out more on the subject by contacting Labotec.