title: A new quantitative and low-cost determination method of nitrate in vegetables, based on deconvolution of UV spectra.
abstract: A new UV-spectrophotometric method for the determination of nitrate in vegetables is presented. The method is based on the spectral deconvolution: UV spectrum of a sample is considered as a linear combination of absorption spectra, named reference spectra. The combination of a small number of spectra of reference allows to reconstitute the shape of UV spectrum of an unknown sample. There have been several fresh vegetables (lettuce, curly lettuce, oak-leaf lettuce), as well as frozen spinaches that have been tested. The results obtained were comparable to those obtained with the reference HPLC method (official European reference method for the determination of nitrate in foodstuffs). The nitrate content varied from 377 to 3240 mg kg(-1) of fresh vegetables, and 545 to 1190 mg kg(-1) of frozen spinach. The recovery of added nitrate ranged from 91 to 99%. The results were obtained with a laboratory spectrophotometer and also with a dedicated field-type spectrophotometer. This method does not require almost any consumable, is quantitative and very fast reading with easy and low maintenance.
authors.affiliation: Chemical Engineering Department, Université de Technologie de Compiègne, BP 20.529, 60205 Compiègne Cedex, France.
authors.forename: Pham Hoai
authors.initials: PH
authors.lastname: Nam
authors.forename: Benitez
authors.initials: B
authors.lastname: Alejandra
authors.forename: Hommet
authors.initials: H
authors.lastname: Frédéric
authors.forename: Bombe
authors.initials: B
authors.lastname: Didier
authors.forename: Schoefs
authors.initials: S
authors.lastname: Olivier
authors.forename: André
authors.initials: A
authors.lastname: Pauss
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000191:economics* / Q000295:instrumentation* / Q000379:methods; D005504:Food Analysis / Q000191:economics* / Q000295:instrumentation* / Q000379:methods; D005506:Food Contamination / Q000032:analysis; D006801:Humans; D018545:Lactuca / Q000378:metabolism; D015233:Models, Statistical; D009566:Nitrates / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000191:economics* / Q000295:instrumentation* / Q000379:methods; D018724:Spinacia oleracea / Q000378:metabolism; D014466:Ultraviolet Rays; D014675:Vegetables / Q000378:metabolism*
chemical_list: D009566:Nitrates