Analysis of phosphorus herbicides by ion-pairing reversed-phase liquid chromatography coupled to inductively coupled plasma mass spectrometry with octapole reaction cell.
A reversed phase ion-pairing high performance liquid chromatographic (RPIP-HPLC) method is developed for the separation of two phosphorus herbicides, Glufosinate and Glyphosate as well as Aminomethylphosphonic acid (AMPA), the major metabolite of Glyphosate. Tetrabutylammonium hydroxide is used as the ion-pairing reagent in conjunction with an ammonium acetate/acetic acid buffering system at pH 4.7. An inductively coupled plasma mass spectrometer (ICP-MS) is coupled to the chromatographic system to detect the herbicides at m/z = 31P. Historically, phosphorus has been recognized as one of the elements difficult to analyze in argon plasma. This is due to its relatively high ionization potential (10.5 eV) as well as the inherent presence of the polyatomic interferences 14N16O1H+ and 15N16O+ overlapping its only isotope at m/z = 31. An octapole reaction cell is utilized to minimize the isobaric polyatomic interferences and to obtain the highest signal-to-background ratio. Detection limits were found to be in the low ppt range (25-32 ng/l). The developed method is successfully applied to the analysis of water samples collected from the Ohio River and spiked with a standard compounds at a level of 20 microg/l.
Sadi
Baki B M
BB
Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, OH 45221-0172, USA.
Vonderheide
Anne P
AP
Caruso
Joseph A
JA
D000613:Aminobutyrates / Q000032:analysis* / Q000302:isolation & purification; D002852:Chromatography, Ion Exchange; D005618:Fresh Water / Q000032:analysis; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000302:isolation & purification; D006371:Helium; D006540:Herbicides / Q000032:analysis* / Q000302:isolation & purification; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000302:isolation & purification; D010758:Phosphorus / Q000032:analysis; D012015:Reference Standards; D014874:Water Pollutants, Chemical / Q000032:analysis; D000097797:Glyphosate
D000613:Aminobutyrates; D005998:Glycine; D006371:Helium; D006540:Herbicides; D007202:Indicators and Reagents; D009943:Organophosphorus Compounds; D010758:Phosphorus; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C003121:phosphinothricin