TY - JOUR
T1 - Spectrophotometric determination of 4,6-dinitro-o-cresol (DNOC) in soil and lemon juice
AU - Uzer, A.
AU - Ercag, E.
AU - Parlar, H.
AU - Apak, R.
AU - Filik, H.
N1 - Funding Information:
One of the researchers (A. Uzer, M.Sc. Chem.) wishes to thank Prof. Dr. Harun Parlar, Head of the Chair of Chemical Technical Analysis and Chemical Food Technology, Technical University of Munich, Germany, for partially providing financial support to this research. Thanks are also extended to Mr.Celal Beysel (Chem. Eng., M.Sc.), president of TURKONFED (Turkish Enterprise and Business Confederation) and of FLOTEKS (Textile & Plastics Co. in Bursa; www.floteks.com.tr ), for his support in the final phase of this research.
PY - 2006/10/27
Y1 - 2006/10/27
N2 - Although the use of once widely applied selective herbicide, 4,6-dinitro-o-cresol (DNOC), was cancelled by US-EPA in 1987, it is still found in soil and water due to its slow degradation in the environment. Since solid phase extraction-spectrophotometry combinations are much simpler and cheaper than chromatography/MS based methods and most routine laboratories lack such sophisticated instrumentation, it is desirable to establish novel sensitive, well-established, and field-applicable spectrophotometric methods for the rapid assay of DNOC in water and soil. For this purpose, two distinct spectrophotometric methods utilizing the periodate and copper(II)-neocuproine (Nc) reagents have been developed following Zn/HCl reduction of the pesticide in a microwave oven for 15 s, and validated for DNOC determination at mg L-1 level. The LOD values were 1.6 and 0.2 mg L-1 for periodate and Cu(II)-Nc methods, respectively. Statistical comparison of the developed methods was made with the aid of high performance liquid chromatography (HPLC) equipped with a C18 (5 μm), 250 mm× 4.6 mm ID reversed phase column in conjunction with a UV (264 nm) detector, and a methanol (HPLC grade) +0.1% glacial acetic acid mixture mobile phase. Both spectrophotometric methods were directly applicable to soil since they were not interfered with common soil cations and anions, together with some pesticides. These methods were applied to real samples such as synthetically contaminated montmorillonite and lemon juice, and overall recovery efficiencies at the order of 95% or greater were achieved in the devised adsorption/elution procedures. An 8-hydroxyquinoline (oxine)-impregnated XAD copolymer resin stabilized with Fe(III) salt was used to preconcentrate DNOC at a concentration factor of 20 from lemon juice contaminated with 1 mg L-1 DNOC, and the analyte retained at pH 2.5 was eluted with 0.025 M methanolic NaOH. Both the devised spectrophotometric methods and the proposed preconcentration column with optimized sorption and desorption conditions are novel for DNOC assay in the natural environment.
AB - Although the use of once widely applied selective herbicide, 4,6-dinitro-o-cresol (DNOC), was cancelled by US-EPA in 1987, it is still found in soil and water due to its slow degradation in the environment. Since solid phase extraction-spectrophotometry combinations are much simpler and cheaper than chromatography/MS based methods and most routine laboratories lack such sophisticated instrumentation, it is desirable to establish novel sensitive, well-established, and field-applicable spectrophotometric methods for the rapid assay of DNOC in water and soil. For this purpose, two distinct spectrophotometric methods utilizing the periodate and copper(II)-neocuproine (Nc) reagents have been developed following Zn/HCl reduction of the pesticide in a microwave oven for 15 s, and validated for DNOC determination at mg L-1 level. The LOD values were 1.6 and 0.2 mg L-1 for periodate and Cu(II)-Nc methods, respectively. Statistical comparison of the developed methods was made with the aid of high performance liquid chromatography (HPLC) equipped with a C18 (5 μm), 250 mm× 4.6 mm ID reversed phase column in conjunction with a UV (264 nm) detector, and a methanol (HPLC grade) +0.1% glacial acetic acid mixture mobile phase. Both spectrophotometric methods were directly applicable to soil since they were not interfered with common soil cations and anions, together with some pesticides. These methods were applied to real samples such as synthetically contaminated montmorillonite and lemon juice, and overall recovery efficiencies at the order of 95% or greater were achieved in the devised adsorption/elution procedures. An 8-hydroxyquinoline (oxine)-impregnated XAD copolymer resin stabilized with Fe(III) salt was used to preconcentrate DNOC at a concentration factor of 20 from lemon juice contaminated with 1 mg L-1 DNOC, and the analyte retained at pH 2.5 was eluted with 0.025 M methanolic NaOH. Both the devised spectrophotometric methods and the proposed preconcentration column with optimized sorption and desorption conditions are novel for DNOC assay in the natural environment.
KW - 4,6-Dinitro-o-cresol assay
KW - Copper(II)-neocuproine
KW - Periodate
KW - Solid phase extraction
KW - Spectrophotometry
KW - XAD-oxine resin
UR - http://www.scopus.com/inward/record.url?scp=33750018998&partnerID=8YFLogxK
U2 - 10.1016/j.aca.2006.07.047
DO - 10.1016/j.aca.2006.07.047
M3 - Article
AN - SCOPUS:33750018998
SN - 0003-2670
VL - 580
SP - 83
EP - 90
JO - Analytica Chimica Acta
JF - Analytica Chimica Acta
IS - 1
ER -