Determination of phosphate in seawater by flow injection analysis with injection of reagent

Abstract

A modification of flow Injection analysis Is described that can Increase the sensitivity of an analysis. The technique was tested by using It for the determination of dissolved phosphate In seawater with the colorimetric phosphomolybdate complex method. The precision of the method Is 1.5% at the 3 µ level, and the detection limit Is 0.05 µ . Samples can be analyzed at rates exceeding 90 samples per hour.

Outcomes of submerged macrophyte restoration in a shallow impounded, eutrophic river

“…At each plot, depth-integrated subsamples were taken from four random points using a 45 mm internal diameter clear plastic tube, and combined for analysis of nutrients, chlorophyll a and turbidity. Standard analytical methods were used to determine total phosphorus and total nitrogen (Valderrama, 1981), filterable reactive phosphorus (Johnson, 1982), nitrate plus nitrite (Johnson, 1983), ammonium-nitrogen (Switala, 1993), and chlorophyll a (APHA, 1995) as an indicator of phytoplankton biomass. Turbidity was analysed in situ (Hach 2100P Turbidimeter).…”

Atomic spectrometric detectors for flow-injection analysis

“…This mixing may be obtained from a combination of several different hydrodynamic regimes of which the flow patterns in the detector cell may be a major contributor. For example, high-sensitivity spectrophotometric procedures have been reported [2] in which the cell volume was 100 µI. Such a cell would be considered unusable for LC detection.…”

Peak width and reagent dispersion in flow injection analysis

“…The use of the reversed f.i.a. configuration (injection of reagent into sample) has been claimed as a means of increasing the sensitivity [15]. The basis of this claim may be examined by applying the relationships derived above.…”