TY - JOUR
T1 - Determination of phosphate in selective extractions for soil iron oxides by the molybdenum blue method in an automated continuance flow injection system
AU - Hass, Amir
AU - Loeppert, Richard H.
AU - Messina, Michael G.
AU - Rogers, Timothy D.
PY - 2011/1
Y1 - 2011/1
N2 - Phosphorus (P) mobility and bioavailability in soil depend on the pools in which it resides. The identification of such pools is essential for the full understanding of P behavior in soil. We evaluated the molybdenum-blue ascorbic-acid method in an automated continuous flow injection analyzer (MB-FIA) to analyze P in two selective soil extractions for soil iron oxide (i.e., the acid ammonium oxalate, AAO, and citrate-dithionite, CD, procedures). Uninterrupted development of the color reaction was obtained at citrate and oxalate concentrations less than 50 mM and 35 mM, corresponding to molybdate/citrate and molybdate/oxalate molar ratios of 2.4 and 3.4, respectively. High precision (% RSD, 1.7 ± 1.3% for CD and 2.9 ± 3.7% for AAO), accuracy, and recoveries (105.7 ± 1.0% for CD and 99.8 ± 3.8% for AAO) were obtained. This study demonstrates the utility of the MB-FIA system for the determination of AAO- and CD-extractable inorganic P.
AB - Phosphorus (P) mobility and bioavailability in soil depend on the pools in which it resides. The identification of such pools is essential for the full understanding of P behavior in soil. We evaluated the molybdenum-blue ascorbic-acid method in an automated continuous flow injection analyzer (MB-FIA) to analyze P in two selective soil extractions for soil iron oxide (i.e., the acid ammonium oxalate, AAO, and citrate-dithionite, CD, procedures). Uninterrupted development of the color reaction was obtained at citrate and oxalate concentrations less than 50 mM and 35 mM, corresponding to molybdate/citrate and molybdate/oxalate molar ratios of 2.4 and 3.4, respectively. High precision (% RSD, 1.7 ± 1.3% for CD and 2.9 ± 3.7% for AAO), accuracy, and recoveries (105.7 ± 1.0% for CD and 99.8 ± 3.8% for AAO) were obtained. This study demonstrates the utility of the MB-FIA system for the determination of AAO- and CD-extractable inorganic P.
UR - http://www.scopus.com/inward/record.url?scp=79960238197&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79960238197&partnerID=8YFLogxK
U2 - 10.1080/00103624.2011.584598
DO - 10.1080/00103624.2011.584598
M3 - Article
AN - SCOPUS:79960238197
SN - 0010-3624
VL - 42
SP - 1619
EP - 1635
JO - Communications in Soil Science and Plant Analysis
JF - Communications in Soil Science and Plant Analysis
IS - 14
ER -