title: Improved Discrimination for Brassica Vegetables Treated with Agricultural Fertilizers Using a Combined Chemometric Approach.
abstract: Multielement and stable isotope (δ(13)C, δ(15)N, δ(2)H, δ(18)O, (207)Pb/(206)Pb, and (208)Pb/(206)Pb) analyses were combined to provide a new chemometric approach to improve the discrimination between organic and conventional Brassica vegetable production. Different combinations of organic and conventional fertilizer treatments were used to demonstrate this authentication approach using Brassica chinensis planted in experimental test pots. Stable isotope analyses (δ(15)N and δ(13)C) of B. chinensis using elemental analyzer-isotope ratio mass spectrometry easily distinguished organic and chemical fertilizer treatments. However, for low-level application fertilizer treatments, this dual isotope approach became indistinguishable over time. Using a chemometric approach (combined isotope and elemental approach), organic and chemical fertilizer mixes and low-level applications of synthetic and organic fertilizers were detectable in B. chinensis and their associated soils, improving the detection limit beyond the capacity of individual isotopes or elemental characterization. LDA shows strong promise as an improved method to discriminate genuine organic Brassica vegetables from produce treated with chemical fertilizers and could be used as a robust test for organic produce authentication.
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Guixian
authors.initials: G
authors.lastname: Hu
authors.affiliation: Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences , Beijing 100081, P.R. China.
authors.forename: Tianjin
authors.initials: T
authors.lastname: Chen
authors.affiliation: Qingdao Academy of Agricultural Sciences , Qingdao 266100, P.R. China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Xiahong
authors.initials: X
authors.lastname: Xu
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Shengzhi
authors.initials: S
authors.lastname: Shao
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Jiahong
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P.R. China.|Key Lab for Pesticide Residue Detection, Ministry of Agriculture , Hangzhou 310021, P.R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: National Isotope Centre, GNS Science , 30 Gracefield Road, Lower Hutt 5040, New Zealand.
authors.forename: Karyne M
authors.initials: KM
authors.lastname: Rogers
mesh_terms: D000383:Agriculture; D001937:Brassica / Q000737:chemistry / Q000254:growth & development*; D002247:Carbon Isotopes / Q000032:analysis; D016002:Discriminant Analysis; D005308:Fertilizers / Q000032:analysis*; D058870:Food, Organic / Q000032:analysis; D013058:Mass Spectrometry; D009587:Nitrogen Isotopes / Q000032:analysis; D058871:Organic Agriculture; D014675:Vegetables / Q000737:chemistry / Q000254:growth & development*
chemical_list: D002247:Carbon Isotopes; D005308:Fertilizers; D009587:Nitrogen Isotopes
keywords: Brassica chinensis; chemometric; linear discriminant analysis (LDA); multielement; stable isotope