Indirect determination of trace amounts of fluoride in natural waters by ion chromatography: a comparison of on-line post-column fluorimetry and ICP-MS detectors

Abstract

An alternative method for the determination of trace levels of fluoride in drinking and sea-water samples is presented. It is based on the formation of the aluminium monofluoride complex in excess of Al3+ and separation of the two species formed (AlF2+ and Al3+) in a small (5 cm long, CG2) ion exchange guard column. The final determination is accomplished by both ICP-MS specific detection and post column derivatisation with fluorimetric detection. Fundamental studies on the formation kinetics of the complex, ion chromatographic separation and optimum aluminium concentration were carried out using spectrofluorimetric detection by post-column reaction of the species with 8-hydroxyquinoline-5-sulfonic acid in a micellar medium of cetyltrimethylammonium bromide. Fluorimetric detection showed good detection limits, but interferences from cations such as Mg2+ and Zn2+ required the use of the longer CS2 ion exchange column. Iron interfered in relatively large amounts but adding EDTA to the sample solution eliminated the interference. A similar separation methodology was applied using ICP-MS detection for the indirect determination of fluoride, by monitoring aluminium at mass 27. In this case, a detection limit of 0.1 ng ml-1 was obtained using 0.45 M HNO3 as eluent and no interference caused by high concentrations of iron was observed. The proposed method was applied to the determination of very low levels of fluoride in natural waters.

Determination of halogens in organic compounds by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS)

“…[7][8][9][10][11][12][13][14] This can be partially attributed to severe spectral interference, the high ionization potentials of these elements, and the memory effects of some of these elements, all of which have seemed too serious to be circumvented. Okamoto 10 reported the determination of fluorine in aqueous samples by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS).…”

Analysis of Fluorine in Drinking Water by ICP-QMS/QMS with an Octupole Reaction Cell

“…8,9 Bayon et al reported a technique that measures the signal of aluminium ion by ICP-MS, following the separation of aluminium monofluoride by ion chromatography. 8 Mores et al reported a technique by measuring the signal of calcium monofluoride by molecular absorption spectromentry. 9 All of these techniques had been shown to be effective for the measurement of fluorine.…”

“…In addition to the above-mentioned direct measurement of fluorine ion by ICP-MS, there are some studies having reported indirect measurement techniques for fluorine. 8,9 Bayon et al reported a technique that measures the signal of aluminium ion by ICP-MS, following the separation of aluminium monofluoride by ion chromatography. 8 Mores et al reported a technique by measuring the signal of calcium monofluoride by molecular absorption spectromentry.…”

Input ion optics of inductively coupled plasma quadrupole mass spectrometers. Part II. Asymmetrical systems with parallel (off-axis) shift of ions

“…По-пытки использования однозарядного отрицатель-ного иона фтора в аргоновой ИСП [192,193] были не слишком успешными. Новую перспективу для Ar ИСП открыла замена одноатомной формы анали-та двухатомной: вместо F + использовали AlF + [194]. Развитие этого подхода с помощью Agilent 8800 ICP-QQQ (МС/МС) [143] опиралось на предвари-тельное образование фторида бария в растворах,…”