Effect of humic substances aggregation on the determination of fluoride in water using an ion selective electrode.
The control of drinking water quality is critical in preventing fluorosis. In this study humic substances (HS) are considered as representative of natural organic matter (NOM) in water. We show that when HS aggregate the response of fluoride ion selective electrodes (ISE) may be perturbed. Dynamic light scattering (DLS) results of both synthetic solutions and natural water sample suggest that low pH and high ionic strength induce HS aggregation. In the presence of HS aggregates, fluoride concentration measured by ISE has a reduction up to 19%. A new "open cage" concept has been developed to explain this reversible phenomenon. The interference of HS aggregation on fluoride measurement can be effectively removed by centrifugation pretreatment.
School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom.
Junjie
J
Shen
School of Engineering and the Built Environment, Edinburgh Napier University, Edinburgh, EH10 5DT, United Kingdom.
Simona
S
Gagliardi
School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom.
Martin R S
MRS
McCoustra
School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom. Electronic address: v.arrighi@hw.ac.uk.
Valeria
V
Arrighi
D060766:Drinking Water / Q000737:chemistry*; D000067493:Dynamic Light Scattering; D005459:Fluorides / Q000737:chemistry*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes; D009994:Osmolar Concentration; D012996:Solutions
D060766:Drinking Water; D006812:Humic Substances; D012996:Solutions; D005459:Fluorides
Dynamic light scattering (DLS); Fluoride; Humic substances; Ion selective electrode (ISE)