TY - JOUR
T1 - Evaluation of diffusion for inorganic-nitrogen analysis of natural water and wastewater
AU - Khan, S. A.
AU - Mulvaney, R. L.
AU - Strle, K.
AU - Horgan, B. P.
PY - 2000/1/1
Y1 - 2000/1/1
N2 -
Public concern that agricultural use of N fertilizers may have adverse effects on environmental quality and human health has led to a growing need for reliable data concerning the concentration of inorganic N in ground and surface water. A study was conducted to compare the accuracy and precision of simple Mason-jar diffusion methods for quantitative determination of NH
4
/
+
and NO
3
/
-
in a wide variety of water and wastewater, relative to colorimetry, ion-selective potentiometry, and steam distillation. Good agreement among methods was generally obtained with standard solutions prepared using deionized water; however, substantial differences often were observed with natural and anthropogenic samples, because of either Cl
-
interference in measurements with the NO
3
/
-
electrode or CO
3
/
2-
interference in distillation. Analytical accuracy also was evaluated by measuring recovery of N added as (NH
4
)
2
SO
4
or KNO
3
(6 mg N L
-1
). With most of the samples studied, quantitative recovery (97-103%) was not achieved by potentiometry or distillation. Quantitative recoveries usually were achieved by a manual Berthelot method for colorimetric determination of NH
4
/
+
, whereas recovery was often incomplete when NO
3
/
-
analyses were performed with an automated flow-injection system using Cd
2+
reduction. Regardless of the sample matrix, diffusion was always accurate in measuring recovery of NH
4
/
+
or NO
3
/
-
.
AB -
Public concern that agricultural use of N fertilizers may have adverse effects on environmental quality and human health has led to a growing need for reliable data concerning the concentration of inorganic N in ground and surface water. A study was conducted to compare the accuracy and precision of simple Mason-jar diffusion methods for quantitative determination of NH
4
/
+
and NO
3
/
-
in a wide variety of water and wastewater, relative to colorimetry, ion-selective potentiometry, and steam distillation. Good agreement among methods was generally obtained with standard solutions prepared using deionized water; however, substantial differences often were observed with natural and anthropogenic samples, because of either Cl
-
interference in measurements with the NO
3
/
-
electrode or CO
3
/
2-
interference in distillation. Analytical accuracy also was evaluated by measuring recovery of N added as (NH
4
)
2
SO
4
or KNO
3
(6 mg N L
-1
). With most of the samples studied, quantitative recovery (97-103%) was not achieved by potentiometry or distillation. Quantitative recoveries usually were achieved by a manual Berthelot method for colorimetric determination of NH
4
/
+
, whereas recovery was often incomplete when NO
3
/
-
analyses were performed with an automated flow-injection system using Cd
2+
reduction. Regardless of the sample matrix, diffusion was always accurate in measuring recovery of NH
4
/
+
or NO
3
/
-
.
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U2 - 10.2134/jeq2000.00472425002900060023x
DO - 10.2134/jeq2000.00472425002900060023x
M3 - Article
AN - SCOPUS:0034327403
SN - 0047-2425
VL - 29
SP - 1890
EP - 1895
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
IS - 6
ER -