1
Recent Advances in Ion-Selective Membrane
Electrodes for In Situ Environmental Water
Analysis
Gastón A. Crespo
School of Chemical
Science and Engineering, Applied Physical
Chemistry Division, KTH
Royal
Institute of Technology, Teknikringen 30, SE-100 44, Stockholm, Sweden
ABSTRACT
Ion-selective membrane electrodes (ISEs) have become very attractive sensing platforms for
environmental water analysis. This review mainly presents recent advances in polymeric-based
ISEs relevant to water research and primarily focused on alkali and alkali earth-metal cations,
ammonium ions, halide anions and certain oxoanions involved in biogeochemical cycles (e.g.
nutrients (NO
2
–
, NO
3
–
), carbon (HCO
3
–
/CO
3
2
–
) and phosphorus (HPO
4
2
–
/H
2
PO
4
–
)).
Clearly, ISEs have the potential to be