The development of iodide-based methods for batch and on-line determinations of phosphite in aqueous samples

Barco, Roman A.; Patil, Deepa G.; Xu, Weihong; Ke, Lin; Khachikian, C. S.; Hanrahan, Grady; Salmassi, Tina M.

doi:10.1016/j.talanta.2006.02.060

Cited by 11 publications

(25 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Experiments were conducted using a modified FIAlab Sequential Injection/Flow Injection Analysis unit (FIAlab Instruments, Model 3500) previously described in Barco et al (2006). The optimized manifold used is shown in Figure 2 and consisted of a miniature fiber-optic spectrometer (Ocean Optics Inc., Dunedin, FL) with two 1024 element linear CCD arrays, a miniature halogen lamp (LS-1 Ocean Optics Inc., Dunedin, FL), a Lab-on-Valve micro channel multipurpose flow cell and an external water bath.…”

Section: Instrumentationmentioning

confidence: 99%

“…Preliminary experiments carried out using our initial univariate optimization approach (Barco et al, 2006) included the following variables: coil length, ascorbic acid concentration and flow rate, ammonium molybdate concentration, combined KI, KIO 3 and ammonium molybdate flow rates (0.42 mL min -1 each in initial studies), reaction temperature, sample volume and KI and KIO 3 concentrations. From these studies sample volume, reaction temperature, combined KI, KIO 3 and ammonium molybdate flow rates and KI and KIO 3 concentrations were found to influence absorbance response appreciably.…”

Section: Experimental Design and Optimizationmentioning

confidence: 99%

“…For the intercomparison study, the optimized FI method was compared to the batch method (reported in Barco et al, 2006) using spiked [10 μM P(+III)] ultra-pure water samples.…”

Section: Experimental Design and Optimizationmentioning

confidence: 99%

“…To help address these issues, we have recently developed new batch and flow injection (FI) on-line methods for the determination of P(+III) based on the oxidation of P(+III) to P(+V) by a mixed-iodide solution containing tri-iodide (I 3 -) and penta-iodide (I 5 -) subunits (Barco et al, 2006). To date, the iodide methods presented above have not been developed for the determination of P(+III) in aqueous samples.…”

Section: Introductionmentioning

confidence: 99%

“…The applicability of the initial on-line method has been shown in the P(+III) determination of aqueous samples (Barco et al, 2006) using a univariate optimization approach. In this paper, the fractional factorial and Box-Behnken designs were employed to determine which factors (and their interactions) had the greatest influence on instrumental response.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Experimental Design and Response Surface Modeling: A Method Development Application for the Determination of Reduced Inorganic Species in Environmental Samples

Hanrahan

Garza²,

Miguel³

et al. 2007

J ENV INFORM

View full text Add to dashboard Cite

ABSTRACT.To confirm the significance of reduced inorganic species in nature, it is important to develop sensitive and selective analytical techniques to detect these species in complex environmental matrices. As a model application, we report on the successful use of fractional factorial and Box-Behnken designs in factor screening, optimization and validation of an on-line flow-injection method for the determination of phosphite [P(+III)] in aqueous samples. Fractional factorial results indicated that the combined KI, KIO 3 and ammonium molybdate flow rates, reaction temperature and KIO 3 concentration were the most important single effects. The main interactive effects were between flow rate and reaction temperature, and between sample volume and reaction temperature. The Box-Behnken design further optimized the response with results confirming the significant single effects of flow rate and temperature as well as the interactive effects between flow rate and reaction temperature. Overall, the model from the Box-Behnken design predicted critical values as: flow rate = 0.40 mL·min -1 , reaction temperature = 47 o C, sample volume = 85 μL, KI reagent concentration = 1.06 g·L -1 and KIO 3 reagent concentration = 0.29 g·L -1 . P(+III) determinations in spiked ultra-pure water were performed using the predicted optimized values from the Box-Behnken design and compared favorably with experimental results. In addition, the potential use of such methodology in the development of sensitive laboratory and field-based methods for the detection of a suite of reduced inorganic species in complex matrices was discussed.

show abstract

Section: Instrumentationmentioning

confidence: 99%

Section: Experimental Design and Optimizationmentioning

confidence: 99%

“…For the intercomparison study, the optimized FI method was compared to the batch method (reported in Barco et al, 2006) using spiked [10 μM P(+III)] ultra-pure water samples.…”

Section: Experimental Design and Optimizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Experimental Design and Response Surface Modeling: A Method Development Application for the Determination of Reduced Inorganic Species in Environmental Samples

Hanrahan

Garza²,

Miguel³

et al. 2007

J ENV INFORM

View full text Add to dashboard Cite

show abstract

Simultaneous determination of phosphonate, phosphate, and diphosphate by capillary electrophoresis using in‐capillary complexation with Mo(VI)

Himeno

Inazuma

Kitano

2007

J of Separation Science

View full text Add to dashboard Cite

This study describes the simultaneous determination of phosphonate, phosphate, and diphosphate by CE with direct UV detection, based on in-capillary complexation with Mo(VI). When a mixture of phosphonate, phosphate, and diphosphate was injected into a capillary containing 3.0 mM Mo(VI), 0.05 M malonate buffer (pH 3.0) and 45% v/v CH3CN, three well-defined peaks, due to the migration of the corresponding polyoxomolybdate anions, were separated. The respective calibration graphs were linear in the concentration range of 2 x 10(-6)-2 x 10(-4) M for phosphonate, 1 x 10(-6)-5 x 10(-5) M for phosphate, and 1 x 10(-6)-2 x 10(-4) M for diphosphate; the correlation coefficients were better than 0.9990. The present CE method is successfully applied to the simultaneous determination of phosphonate, phosphate, and diphosphate in tap water.

show abstract

On‐line chloride removal from ion chromatography for trace‐level analyses of phosphite and other anions by coupled ion chromatography–inductively coupled plasma mass spectrometry

Baidya,

Stüeken

2023

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

RationaleIon chromatography (IC) combined with inductively coupled plasma mass spectrometry (ICPMS) is an ideal tool for measuring low concentrations of anionic species such as phosphite; however, the high concentration of chloride and other anions in natural solutions may negatively impact chromatographic separation and data quality.MethodWe developed an on‐line mechanism of removing chloride from a sample within an ion chromatograph, using an additional valve and a separation column that transfers chloride to waste while phosphite and most other anions are retained. We installed this system in a coupled IC/ICPMS system (ICS6000 and Element 2 in medium‐resolution mode) and determined linearity and detection limits. In addition, we measured phosphorus species by NMR for comparison as an alternative method for phosphite determination.ResultsChloride was fully removed from the samples while phosphite was retained and could be analysed by IC/ICPMS. Concentrations could be measured down to 0.003 μmol/L and possibly less with good linearity over the explored range (up to 1.615 μmol/L; r2 = 0.999). In contrast, the detection limit by NMR was 6.46 μmol/L.ConclusionsThe on‐line removal mechanism works well for simplifying sample matrices. It removes the need for costly pre‐analytical sample treatment with OnGuard columns. We confirm that IC/ICPMS is the most powerful technique for quantifying phosphite in natural solutions. The new chloride‐removal method may also be applicable to analyses of other anions.

show abstract

The development of iodide-based methods for batch and on-line determinations of phosphite in aqueous samples

Cited by 11 publications

References 29 publications

Experimental Design and Response Surface Modeling: A Method Development Application for the Determination of Reduced Inorganic Species in Environmental Samples

Experimental Design and Response Surface Modeling: A Method Development Application for the Determination of Reduced Inorganic Species in Environmental Samples

Simultaneous determination of phosphonate, phosphate, and diphosphate by capillary electrophoresis using in‐capillary complexation with Mo(VI)

On‐line chloride removal from ion chromatography for trace‐level analyses of phosphite and other anions by coupled ion chromatography–inductively coupled plasma mass spectrometry

Contact Info

Product

Resources

About