title: Determination of linuron in potatoes using capillary column gas chromatography/mass spectrometry.
abstract: A convenient method for the determination of the N-methyl,N-methoxy-phenylurea herbicide (linuron) in potatoes has been developed. The herbicide is extracted from potatoes using a slightly modified Luke multiresidue procedure. The extract is analyzed directly by gas chromatography with cold on-column injection, using an ion trap mass spectrometer in the chemical ionization mode as the detector. Quantitation is performed using p-bromonitrobenzene as the internal standard. The limit of detection is 0.1 ppm. Recoveries of linuron in potatoes averaged 112 +/- 6% at the 0.5 ppm level, and 110 +/- 2% at the 0.2 ppm level. No linuron residues were found in 25 potato samples that were analyzed by this method. Two other N-methyl,N-methoxy-phenylurea herbicides, metobromuron and chlorbromuron, are also sufficiently stable to be determined by this method, but the N,N-dialkyl-phenylurea herbicides neburon, diuron, and monuron are too thermally unstable and degrade in the gas chromatograph.
authors.affiliation: Rutgers University, Cook College, Department of Food Science, New Brunswick, NJ 08903.
authors.forename: G C
authors.initials: GC
authors.lastname: Mattern
authors.forename: G M
authors.initials: GM
authors.lastname: Singer
authors.forename: J
authors.initials: J
authors.lastname: Louis
authors.forename: M
authors.initials: M
authors.lastname: Robson
authors.forename: J D
authors.initials: JD
authors.lastname: Rosen
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D006540:Herbicides / Q000032:analysis*; D007202:Indicators and Reagents; D008044:Linuron / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D011198:Solanum tuberosum / Q000032:analysis*
chemical_list: D006540:Herbicides; D007202:Indicators and Reagents; D010573:Pesticide Residues; D008044:Linuron