On-Line Determination of Dissolved Silica in Seawater by Ion Exclusion Chromatography in Combination with Inductively Coupled Plasma Mass Spectrometry

Abstract

A method for the direct determination of dissolved silica in seawater by ion exclusion chromatography in combination with inductively coupled plasma mass spectrometry is described. This method was developed as a second, independent method to complement the usual colorimetric procedure in the determination of a certified concentration of dissolved silica in a planned seawater reference material. Ion exclusion affords a separation of the dissolved silica not only from the major seawater cations but also from potentially interfering anions. The detection limit, conservatively estimated at 2.3 ng g -1 as Si (0.08 µM), is superior to that achievable by direct analysis by inductively coupled plasma atomic emission spectrometry.

Preparation and certification of a reference material for the determination of nutrients in seawater

“…Although it has been shown in this paper and reported that gamma irradiation slightly alters the nutrient concentrations [10], our experience with MOOS-1 over six years has shown exceptional stability. This material does not possess ideal nutrient concentrations for the study of some oceanographic processes as outlined in the NAS report [1], however, it is hoped that MOOS-1 will partially fill a void and become a useful quality assurance tool for nutrient measurements.…”

“…A Perkin-Elmer Elan 6000 ICP-MS (Concord ON, Canada) was interfaced with a Model AGP-1 advanced gradient pump (Dionex, Sunnyvale, CA) for the measurement of orthophosphate [9] and silicate [10]. An ion chromatography system consisting of a Waters 600 s Controller, 626 Dual Pump, and 486 UV Detector (Waters Corporation, Milford MA) was used for nitrite and nitrate determinations.…”

“…An ion chromatographic procedure with UV absorbance detection was developed for NO 3 -and NO 2 -determinations. Methods for the direct determination of orthophosphate [9] and dis- [10] in seawater by ICP-MS in combination with ion-exclusion chromatography (IEC) were also developed. IEC can be used to provide a temporal separation of the dissolved analytes from the major seawater ions to permit their direct determination despite the high dissolved solids content of the sample.…”

A Coulometric Analysis Method and an Ion-exclusion Chromatographic Method for the Determination of Antimony(V) in Large Excess of Antimony(III)

“…16 min probably resulted from slightly dissolved carbon dioxide, judging from our previous study using the same kind of ion-exclusion column. 54 The small peak at 19 min was from antimony(V), which was ascertained by standard addition. Figure 4 indicates the dependencies of the retention time of antimony(V) on the concentration of the sulfuric acid eluent.…”

Simultaneous determination of silicic acid, Ca, Mg and Al in mineral water and composite tablets by Ion chromatography

“…Sakai et al [5] determined silicate by ion-exclusion chromatography (IEC) using luminol chemiluminescence (CL) detection. Hioki et al [6] described a method for the direct determination of dissolved silica in seawater by IEC combined with inductively coupled plasma mass spectrometry. Li et al [7] recently reported a method for the direct determination of silicate in water by IEC with conductivity detection.…”