Phosphate Ions In Water Research Articles

Application of photoacoustic spectrometry to flow-injection analysis

Photoacoustic spectrometry (PAS) based on pulsed laser excitation has been coupled to flow-injection analysis (FIA) to detect nitrite, nitrate, iron, ammonia, and phosphate ions in water with the aim to verify its potentiality with respect to conventional FIA systems. Excitation has been performed by means of a Nd:YAG laser with a 2nd harmonic generation and a dye laser; a conventional flow-injection cell has been used as photoacoustic cell. Standard solutions and real samples such as ground water, river water, fog and waste water have been analyzed. A good agreement has been obtained between the results of the proposed technique and those of traditional laboratory techniques. The best analytical configuration, in terms of loop length and integration time, has been also defined. The performance as limit of detection (LOD) was comparable for both techniques. The main points to be developed in order to improve the analytical response of PAS-FIA are reported.

Determination of trace phosphate ion in water by visual method after preconcentration on a membrane filter for field work

A sensitive visual method based on comparing the color intensity of precipitate as phosphomolybdenum blue on a membrane filter, has been developed for the determination of trace phosphate ion in water for field work. A sample solution containing 0.05–5.0 μg of phosphate was treated in a 25-ml polypropylene syringe, and the resulting precipitate was filtered through a membrane filter attached to the syringe. The color intensity of the precipitate on the membrane filter was measured visually following the standard series method. The coefficient of variation for five measurements at 0.5 μg of phosphate is 11%. The detection limit is 0.02 μg of phosphate ion in 22.5 ml (0.9 μg PO 3− 4/l) of water sample when the effective filtration area is 0.78 cm 2. The interference of various ions was studied and optimum conditions were developed for the determination of phosphate ion in natural water.

Preconcentration method for trace amounts of phosphate ion in water using zirconium dioxide.

Preconcentration method for trace amounts of phosphate ion in water using zirconium dioxide.

Semiquantitative and Quantitative Determination of Trace Amount of Phosphate Ion in Water Using Polyurethane Foam Thin -Layer Colorimetry

Abstract A simple, sensitive and fast method for the colorimetric determination of phosphate ion in water is described. The method is based on spectrophotometric measurement of the blue molybdoantimony phosphoric acid species sorbed in a polyurethane foam thin-layer for quantitative determination of phosphate ion, or the visual color comparison technique for rapid semiquantitative determination. The detection limit for the quantitative procedure is 5 μg/1 and for semiquantitative procedure 20 μg/1 for sample volumes of 100 ml and 25 ml, respectively.