Premium
Nondegradative Extraction and Measurement of Uric Acid from Poultry Litter
Author(s) -
Mowrer Jake,
Kissel David E.,
Cabrera Miguel,
Hassan Sayed M.
Publication year - 2013
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/sssaj2012.0337
Subject(s) - chemistry , uric acid , extraction (chemistry) , chromatography , high performance liquid chromatography , sodium , sodium acetate , reagent , detection limit , analyte , solubility , poultry litter , nuclear chemistry , biochemistry , organic chemistry , nutrient
Due to limited solubility of uric acid from poultry litter (PL), alkaline solutions are frequently used to extract uric acid from PL for measurement, but the high pH can cause oxidation of the analyte. Our objective was to compare 0.1 M sodium acetate, 0.025 M Li 2 CO 3 , and a NaOH/Na 2 PO 4 buffer as a means of extracting uric acid from PL for analysis by high‐pressure liquid chromatography (HPLC). In laboratory experiments, extractant‐induced degradation of reagent uric acid proceeded at a rate of 80 g kg −1 d −1 in 0.025 M of Li 2 CO 3 (pH 11.2) and a NaOH/Na 2 PO 4 buffer (pH 12.4) compared with no degradation in sodium acetate over a 2‐d period. In extracted PL samples, the alkaline extractants were found to enhance the enzymatic oxidation of uric acid to completion in Li 2 CO 3 and by 800 g kg −1 in a NaOH/Na 2 PO 4 buffer over the same 2‐d period. Sodium acetate extraction resulted in minimal loss of analyte (30 g kg −1 ), possibly due to thermal inactivation of the responsible enzyme uricase. Stabilization of the dissolved uric acid extracted from PL samples allowed for the development of a very accurate measurement procedure by HPLC with ultraviolet (UV)–visible light spectrometer (VIS) detection at 290 nm. Our results suggest a reporting limit of 8.5 mg uric acid–N kg −1 of litter. Of the 118 PL samples that were analyzed in this study, uric acid‐, ammonium‐, and nitrate‐N concentrations accounted for an average of 9.4, 17.4, and 1.2%, respectively, of the total N present in PL.