Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system

A new extraction procedure based on an off-line extraction column was proposed for extracting of available phosphorus from soils. The column was fabricated from a plastic syringe fitted at the bottom with a cotton wool and a piece of filter paper to support a soil sample. An aliquot (50 mL) of extra...

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Main Authors: Jakmunee J., Junsomboon J.
Format: Article
Language:English
Published: 2014
Online Access:http://www.ncbi.nlm.nih.gov/pubmed/3502482
http://cmuir.cmu.ac.th/handle/6653943832/6069
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Institution: Chiang Mai University
Language: English
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spelling th-cmuir.6653943832-60692014-08-30T03:23:48Z Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system Jakmunee J. Junsomboon J. A new extraction procedure based on an off-line extraction column was proposed for extracting of available phosphorus from soils. The column was fabricated from a plastic syringe fitted at the bottom with a cotton wool and a piece of filter paper to support a soil sample. An aliquot (50 mL) of extracting solution (0.05 M HCl+0.0125 M H(2)SO(4)) was used to extract the sample under gravity flow and the eluate was collected in a polyethylene bottle. The extract was then analyzed for phosphorus contents by a simple flow injection amperometric system, employing a set of three-way solenoid valves as an injection valve. The method is based on the electrochemical reduction of 12-molybdophosphate which is produced on-line by the reaction of orthophosphate with acidic molybdate and the electrical current produced was directly proportional to the concentration of phosphate in range of 0.1-10.0 mg L(-1) PO(4)-P, with a detection limit of 0.02 mg L(-1). Relative standard for 11 replicate injections of 5 mg L(-1) PO(4)-P was 0.5%. A sample through put of 35 h(-1) was achieved, with consumption of 14 mg KCl, 10mg ammonium molybdate and 0.05 mL H(2)SO(4) per analysis. The detection system does not suffer from the interferences that are encountered in the photometric method such as colored substances, colloids, metal ions, silicate and refractive index effect (Schlieren effect). The results obtained by the column extraction procedure were well correlated with those obtained by the steady-state extraction procedure, but showed slightly higher extraction efficiency. 2014-08-30T03:23:48Z 2014-08-30T03:23:48Z 2009 Journal Article 1873-3573 19615512 http://www.ncbi.nlm.nih.gov/pubmed/3502482 http://cmuir.cmu.ac.th/handle/6653943832/6069 eng
institution Chiang Mai University
building Chiang Mai University Library
country Thailand
collection CMU Intellectual Repository
language English
description A new extraction procedure based on an off-line extraction column was proposed for extracting of available phosphorus from soils. The column was fabricated from a plastic syringe fitted at the bottom with a cotton wool and a piece of filter paper to support a soil sample. An aliquot (50 mL) of extracting solution (0.05 M HCl+0.0125 M H(2)SO(4)) was used to extract the sample under gravity flow and the eluate was collected in a polyethylene bottle. The extract was then analyzed for phosphorus contents by a simple flow injection amperometric system, employing a set of three-way solenoid valves as an injection valve. The method is based on the electrochemical reduction of 12-molybdophosphate which is produced on-line by the reaction of orthophosphate with acidic molybdate and the electrical current produced was directly proportional to the concentration of phosphate in range of 0.1-10.0 mg L(-1) PO(4)-P, with a detection limit of 0.02 mg L(-1). Relative standard for 11 replicate injections of 5 mg L(-1) PO(4)-P was 0.5%. A sample through put of 35 h(-1) was achieved, with consumption of 14 mg KCl, 10mg ammonium molybdate and 0.05 mL H(2)SO(4) per analysis. The detection system does not suffer from the interferences that are encountered in the photometric method such as colored substances, colloids, metal ions, silicate and refractive index effect (Schlieren effect). The results obtained by the column extraction procedure were well correlated with those obtained by the steady-state extraction procedure, but showed slightly higher extraction efficiency.
format Article
author Jakmunee J.
Junsomboon J.
spellingShingle Jakmunee J.
Junsomboon J.
Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
author_facet Jakmunee J.
Junsomboon J.
author_sort Jakmunee J.
title Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
title_short Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
title_full Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
title_fullStr Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
title_full_unstemmed Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
title_sort determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system
publishDate 2014
url http://www.ncbi.nlm.nih.gov/pubmed/3502482
http://cmuir.cmu.ac.th/handle/6653943832/6069
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