Premium
Ion Chromatographic Determination of Sulfate and Nitrate in Soils
Author(s) -
Dick W. A.,
Tabatabai M. A.
Publication year - 1979
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1979.03615995004300050016x
Subject(s) - chemistry , ion chromatography , soil water , sulfate , chromatography , ion exchange , nitrate , column chromatography , extraction (chemistry) , detection limit , thermal conductivity detector , ion , soil test , thiourea , ion exchange resin , analytical chemistry (journal) , inorganic chemistry , gas chromatography , geology , soil science , organic chemistry
A simple and precise ion chromatographic (IC) method for determination of SO 4 2‐ and NO 3 ‐ in soils is described. It involves determination of these anions in soil extracts by using a Dionex Model 10 Ion Chromatograph. An aliquot (≃2 ml) of soil extract is injected in the eluent stream (3.0m M NaHCO 3 + 1.8m M Na 2 CO 3 ), and the anions are separated by an analytical column containing Dionex low‐capacity anion‐exchange resin in the HCO 3 ‐ form and converted to the corresponding acids by a suppressor column containing a strong acid cation‐exchange resin in the H + form. Conductivity is used as the mode of detection. Results of SO 4 2‐ and NO 3 ‐ in soils by the IC method agreed closely with those obtained by the methylene blue and steam‐distillation methods, respectively. Tests indicated that S 2‐ , SO 3 2‐ , S 2 O 3 2‐ , S 2 O 5 2‐ , S 4 O 6 2‐ , SCN ‐ , thiourea, glucose‐6‐sulfate, and p ‐nitrophenyl sulfate do not interfere in determination of SO 4 2‐ . Also, NO 2 ‐ does not interfere in determination of NO 3 ‐ . This method gives quantitative recovery of SO 4 ‐S and NO 3 ‐N added to soils (5–50 µg/g soil). The detection limit is 1 µg SO 4 ‐S or NO 3 ‐N/g soil (0.2 µg SO 4 ‐S or NO 3 ‐N/ml of soil extract). With the IC method, SO 4 ‐S and NO 3 ‐N can be determined simultaneously in about 10 min.