In this work, hydrolysis of three different hexafluorophosphate salts in purified water was investigated. Aqueous samples of lithium hexafluorophosphate (LiPF₆), sodium hexafluorophosphate (NaPF₆) and potassium hexafluorophosphate (KPF 6) were prepared and stored for different times. Ion chromatography (IC) with UV as well as non-suppressed and suppressed conductivity detection was used for the analysis of the reaction products. For the detection and identification of the formed decomposition products, an IC method using IonPac AS14A 250mm × 4.0mm i.d. column and 2.5mM KHCO₃-2.5mM K₂CO₃ eluent was established. Besides hexafluorophosphate, four other anionic species were detected in fresh and matured aqueous solutions. The hydrolysis products fluoride (F^-), monofluorophosphate (HPO₃F^-), phosphate (HPO₄^2-) and difluorophosphate (PO₂F₂^-) were found and were unambiguously identified by means of standards or electrospray ionization mass spectrometry (ESI-MS). It was shown that stability of hexafluorophosphate solutions depends on the nature of the counter ion and decreases in the order potassium>sodium>lithium.

Item Type:	Refereed Article
Keywords:	hexafluorophosphate salts, ion chromatography, hydrolysis, photometric detection, conductivity
Research Division:	Chemical Sciences
Research Group:	Analytical Chemistry
Research Field:	Separation Science
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Chemical Sciences
Author:	Terborg, L (Ms Lydia Terborg)
Author:	Haddad, PR (Professor Paul Haddad)
Author:	Nesterenko, PN (Professor Pavel Nesterenko)
ID Code:	82807
Year Published:	2012
Web of Science® Times Cited:	57
Deposited By:	Austn Centre for Research in Separation Science
Deposited On:	2013-02-19
Last Modified:	2013-06-06
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